Solution of Schrödinger’s equation for the hydrogen atom shows that the electron can only have certain allowed wave functions (eigenfunctions). Each of these corresponds to a probability distribution in space given by the manner in which

Ψ
2 varies with position. They also have an associated value of the energy ‘E’. These allowed wave functions, or orbitals, are characterized by three quantum numbers similar to those characterized the allowed orbits in the earlier quantum theory of the atom:

‘n’, the ‘principal quantum number, can have values of 1, 2, 3, etc. the orbital with n =1 has the lowest energy. The states of the electron with n = 1, 2, 3, etc., are called ‘shells’ and designate the K, L, M shells, etc. ‘I’, the ‘azimuthal quantum numbers’, which for a given value of ‘n’ can have values of 0, 1, 2, . . . ( n‒1 ). An electron in the ‘L’ shell of an atom with n = 2 can occupy two sub-shells of different energy corresponding to I = 0, I = 1, and I = 2. Orbitals with I = 0, 1, 2 and 3 are called s, p, d, and ƒ orbitals respectively. The significance of I quantum number is that it gives the angular momentum of the electron. The orbital angular momentum of an electron is given by:

[I( I + 1 )( h/2π).

‘m’, the ‘magnetic quantum number, which for a given value of I can have values’

‒ I, ‒( I - 1 ), . . . , 0, . . . ( I - 1 ), I.À

Thus, for a ‘p’ orbital for orbits with m = 1, 0, and 1. These orbitals, with the same values of ‘n’ and ‘I’ but different ‘m’ values, have the same energy. The significance of this quantum number is that it indicates the number of different levels that would be produced if the atom were subjected to an external magnetic field.

According to wave theory the electron may be at any distance from the nucleus, but in fact, there is only a reasonable chance of it being within a distance of ~ 5 x 10-11 metre. Indeed the maximum probability occurs when r - a0 where a0 is the radius of the first Bohr orbit. It is customary to represent an orbital by a surface enclosing a volume within which there is an arbitrarily decided probability (say 95% ) of finding the electron.

Finally, the electron in an atom can have a fourth quantum number MS, characterizing its spin direction. This can be + ½ or ‒ ½, and according to the “Pauli Exclusion Principle,” each orbital can hold only two electrons. The four quantum numbers lead to an explanation of the periodic table of the elements.

In earlier mention, the concerns referring to the ‘moment’ had been to our exchanges to issue as, i.e., the moment of inertia, moment of momentum. The moment of a force about an axis is the product of the perpendicular distance of the axis from the line of action of the force, and the component of the force in the plane perpendicular to the axis. The moment of a system of coplanar forces about an axis perpendicular to the plane containing them is the algebraic sum of the moments of the separate forces about that axis of a anticlockwise moment appear taken controventionally to be positive and clockwise of ones uncomplementarity. The moment of momentum about an axis, symbol L is the product to the moment of inertia and angular velocity (Iω). Angular momentum is a pseudo-vector quality, as it is connected in an isolated system. It is a scalar and is given a positive or negative sign as in the moment of force. When contending to systems, in which forces and motions do not all lie in one plane, the concept of the moment about a point is needed. The moment of a vector P, e.g., force or momentous pulsivity, from which a point ‘A’ is a pseudo-vector M equal to the vector product of r and P, where r is any line joining ‘A’ to any point ‘B’ on the line of action of P. The vector product M = r x p is independent of the position of ‘B’ and the relation between the scalar moment about an axis and the vector moment about which a point on the axis is that the scalar is the component of the vector in the direction of the axis.

The linear momentum of a particle ‘p’ is the product of the mass and the velocity of the particle. It is a vector quality directed through the particle in the direction of motion. The linear momentum of a body or of a system of particles is the vector sum of the linear momenta of the individual particle. If a body of mass ‘M’ is translated with a velocity ‘V’, its momentum is MV, which is the momentum of a particle of mass ‘M’ at the centre of gravity of the body. (1) In any system of mutually interacting or impinging particles, the linear momentum in any fixed direction remains unaltered unless there is an external force acting in that direction. (2) Similarly, the angular momentum is constant in the case of a system rotating about a fixed axis provided that no external torque is applied.

Subatomic particles fall into two major groups: The elementary particles and the hadrons. An elementary particle is not composed of any smaller particles and therefore represents the most fundamental form of matter. A hadron is composed of panicles, including the major particles called quarks, the most common of the subatomic particles, includes the major constituents of the atom -the electron is an elementary particle, and the proton and the neutron (hadrons). An elementary particle with zero charge and a rest mass equal to

1.674 9542 x 10-27 kg,

i.e., 939.5729 MeV / c2.

It is a constituent of every atomic nucleus except that of ordinary hydrogen, free neutrons decay by ‘beta decay’ with a mean life of 914 s. the neutron has spin ½, Isospin ½, and positive parity. It is a ‘fermion’ and is classified as a ‘hadron’ because it has strong interaction.

Neutrons can be ejected from nuclei by high-energy particles or photons, the energy required is usually about 8 MeV, although sometimes it is less. The fission is the most productive source. They are detected using all normal detectors of ionizing radiation because of the production of secondary particles in nuclear reactions. The discovery of the neutron (Chadwick, 1932) involved the detection of the tracks of protons ejected by neutrons by elastic collisions in hydrogenous materials.

Unlike other nuclear particles, neutrons are not repelled by the electric charge of a nucleus so they are very effective in causing nuclear reactions. When there is no ‘threshold energy’, the interaction ‘cross sections’ become very large at low neutron energies, and the thermal neutrons produced in great numbers by nuclear reactions cause nuclear reactions on a large scale. The capture of neutrons by the (n, ϒ) process produces large quantities of radioactive materials, both useful nuclides such as 66Co for cancer therapy and undesirable by-products. The least energy required to cause a certain process, in particular a reaction in nuclear or particle physics. It is often important to distinguish between the energies required in the laboratory and in centre-of-mass co-ordinates. In “fission” the splitting of a heavy nucleus of an atom into two or more fragments of comparable size usually as the result of the impact of a neutron on the nucleus. It is normally accompanied by the emission of neutrons or gamma rays. Plutonium, uranium, and thorium are the principle fissionable elements

In nuclear reaction, a reaction between an atonic nucleus and a bombarding particle or photon leading to the creation of a new nucleus and the possible ejection of one or more particles. Nuclear reactions are often represented by enclosing brackets and symbols for the incoming and final nuclides being shown outside the brackets. For example: 14N (α, p)17O.

Energy from nuclear fissions, on the whole, the nucleuses of atoms of moderate size are more tightly held together than the largest nucleus, so that if the nucleus of a heavy atom can be induced to split into two nuclei and moderate mass, there should be considerable release of energy. By Einstein’ s law of the conservation of mass and energy, this mass and energy difference is equivalent to the energy released when the nucleons binding differences are equivalent to the energy released when the nucleons bind together. Y=this energy is the binding energy, the graph of binding per nucleon, EB. A increases rapidly up to a mass number of 50-69 (iron, nickel, etc.) and then decreases slowly. There are therefore two ways in which energy can be released from a nucleus, both of which can be released from the nucleus, both of which entail a rearrangement of nuclei occurring in the lower as having to curve into form its nuclei, in the upper, higher-energy part of the curve. The fission is the splitting of heavy atoms, such as uranium, into lighter atoms, accompanied by an enormous release of energy. Fusion of light nuclei, such as deuterium and tritium, releases an even greater quantity of energy.

The work that must be done to detach a single particle from a structure of free electrons of an atom or molecule to form a negative ion. The process is sometimes called ‘electron capture, but the term is more usually applied to nuclear processes. As many atoms, molecules and free radicals from stable negative ions by capturing electrons to atoms or molecules to form a negative ion. The electron affinity is the least amount of work that must be done to separate from the ion. It is usually expressed in electro-volts

The uranium isotope 235U will readily accept a neutron but one-seventh of the nuclei stabilized by gamma emissions while six-sevenths split into two parts. Most of the energy released amounts to about 170 MeV, in the form of the kinetic energy of these fission fragments. In addition an averaged of 2.5 neutrons of average energy 2 MeV and some gamma radiation is produced. Further energy is released later by radioactivity of the fission fragments. The total energy released is about 3 x 10-11 joule per atom fissioned, i.e., 6.5 x 1013 joule per kg conserved.

To extract energy in a controlled manner from fissionable nuclei, arrangements must be made for a sufficient proportion of the neutrons released in the fissions to cause further fissions in their turn, so that the process is continuous, the minium mass of a fissile material that will sustain a chain reaction seems confined to nuclear weaponry. Although, a reactor with a large proportion of 235U or plutonium 239Pu in the fuel uses the fast neutrons as they are liberated from the fission, such a rector is called a ‘fast reactor’. Natural uranium contains 0.7% of 235U and if the liberated neutrons can be slowed before they have much chance of meeting the more common 238U atom and then cause another fission. To slow the neutron, a moderator is used containing light atoms to which the neutrons will give kinetic energy by collision. As the neutrons eventually acquire energies appropriate to gas molecules at the temperatures of the moderator, they are then said to be thermal neutrons and the reactor is a thermal reactor.

Then, of course, the Thermal reactors, in typical thermal reactors, the fuel elements are rods embedded as a regular array in which the bulk of the moderator that the typical neutron from a fission process has a good chance of escaping from the relatively thin fuel rod and making many collisions with nuclei in the moderator before again entering a fuel element. Suitable moderators are pure graphite, heavy water (D2O), are sometimes used as a coolant, and ordinary water (H2O). Very pure materials are essential as some unwanted nuclei capture neutrons readily. The reactor core is surrounded by a reflector made of suitable material to reduce the escape of neutrons from the surface. Each fuel element is encased e. g., in magnesium alloy or stainless steel, to prevent escape of radioactive fission products. The coolant, which may be gaseous or liquid, flows along the channels over the canned fuel elements. There is an emission of gamma rays inherent in the fission process and, many of the fission products are intensely radioactive. To protect personnel, the assembly is surrounded by a massive biological shield, of concrete, with an inner iron thermal shield to protect the concrete from high temperatures caused by absorption of radiation.

To keep the power production steady, control rods are moved in or out of the assembly. These contain material that captures neutrons readily, e.g., cadmium or boron. The power production can be held steady by allowing the currents in suitably placed ionization chambers automatically to modify the settings of the rods. Further absorbent rods, the shut-down rods, are driven into the core to stop the reaction, as in an emergence if the control mechanism fails. To attain high thermodynamic efficiency so that a large proportion of the liberated energy can be used, the heat should be extracted from the reactor core at a high temperature.

In fast reactors no mediator is used, the frequency of collisions between neutrons and fissile atoms being creased by enriching the natural uranium fuel with 239Pu or additional 235U atoms that are fissioned by fast neutrons. The fast neutrons are thus built up a self-sustaining chain reaction. In these reactions the core is usually surrounded by a blanket of natural uranium into which some of the neutrons are allowed to escape. Under suitable conditions some of these neutrons will be captured by 238U atoms forming 239U atoms, which are converted to 239Pu. As more plutonium can be produced than required to enrich the fuel in the core, these are called ‘fast breeder reactors’.

Thus and so, a neutral elementary particle with spin½, that only takes part in weak interactions. The neutrino is a lepton and exists in three types corresponding to the three types of charged leptons, that is, there are the electron neutrinos (ve) tauon neutrinos (vμ) and tauon neutrinos (vτ). The antiparticle of the neutrino is the antineutrino.

Neutrinos were originally thought to have a zero mass, but recently there have been some advances to an indirect experiment that evince to the contrary. In 1985 a Soviet team reported a measurement for the first time, of a non-zero neutrino mass. The mass measured was extremely small, some 10 000 times smaller than the mass of the electron. However, subsequent attempts to reproduce the Soviet measurement were unsuccessful. More recent (1998-99), the Super-Kamiokande experiment in Japan has provided indirect evidence for massive neutrinos. The new evidence is based upon studies of neutrinos, which are created when highly energetic cosmic rays bombard the earth’s upper atmosphere. By classifying the interaction of these neutrinos according to the type of neutrino involved ( an electron neutrino or muon neutrino ), and counting their relative numbers as a function: An oscillatory behaviour may be shown to occur. Oscillation in this sense is the charging back and forth of the neutrino’s type as it travels through space or matter. The Super-Kamiokande result indicates that muon neutrinos are changing into another type of neutrino, e.g., sterile neutrinos. The experiment does not, however, determine directly the masses, though the oscillations suggest very small differences in mass between the oscillating types.

The neutrino was first postulated (Pauli 1930)to explain the continuous spectrum of beta rays. It is assumed that there is the same amount of energy available for each beta decay of a particle nuclide and that energy is shared according to a statistical law between the electron and a light neutral particle, now classified as the anti-neutrino, ύe Later it was shown that the postulated particle would also conserve angular momentum and linear momentum in the beta decays.

In addition to beta decay, the electron neutrino is also associated with, for example, positron decay and electron capture:

22Na → 22Ne + e+ + ve

55Fe + e‒ → 55Mn + ve

The absorption of anti-neutrinos in matter by the process

1H + ΰe ➝ n + e+

was first demonstrated by Reines and Cowan? The muon neutrino is generated in such processes as:

π+ → μ+ + vμ

Although the interactions of neutrinos are extremely weak the cross sections increase with energy and reaction can be studied at the enormous energies available with modern accelerators in some forms of ‘grand unification theories’, neutrinos are predicted to have a non-zero mass. Nonetheless, no evidences have been found to support this prediction.

The antiparticle of an electron, i.e., an elementary particle with electron mass and positive charge and equal to that of the electron. According to the relativistic wave mechanics of Dirac, space contains a continuum of electrons in states of negative energy. These states are normally unobservable, but if sufficient energy can be given, an electron may be raised into a state of positivity and become observable. The vacant state of negativity seems to behave as a positive particle of positive energy, which is observed as a positron.

A theory of elementary particles based on the idea that the fundamental entities are not point-like particles, but finite lines (strings) or closed loops formed by stings. The original idea was that an elementary particle was the result of a standing wave in a string. A considerable amount of theoretical effort has been put into development string theories. In particular, combining the idea of strings with that of super-symmetry, which has led to the idea with which correlation holds strongly with super-strings. This theory may be a more useful route to a unified theory of fundamental interactions than quantum field theory, simply because it’s probably by some unvioded infinites that arise when gravitational interactions are introduced into field theories. Thus, superstring theory inevitably leads to particles of spin 2, identified as gravitons. String theory also shows why particles violate parity conservation in weak interactions.

Superstring theories involve the idea of higher dimensional spaces: 10 dimensions for fermions and 26 dimensions for bosons. It has been suggested that there are the normal 4 space-time dimensions, with the extra dimension being tightly ‘curved’. Still, there are no direct experimental evidences for super-strings. They are thought to have a length of about 10-35 m and energies of 1014 GeV, which is well above the energy of any accelerator. An extension of the theory postulates that the fundamental entities are not one-dimensional but two-dimensional, i.e., they are super-membranes.

Allocations often other than what are previous than in time, awaiting the formidable combinations of what precedes the presence to the future, because of which the set of invariance of a system, a symmetry operation on a system is an operation that does not change the system. It is studied mathematically using “Group Theory.” Some symmetries are directly physical, for instance the reelections and rotations for molecules and translations in crystal lattices. More abstractively the implicating inclinations toward abstract symmetries involve changing properties, as in the CPT Theorem and the symmetries associated with “Gauge Theory.” Gauge theories are now thought to provide the basis for a description in all elementary particle interactions. The electromagnetic particle interactions are described by quantum electrodynamics, which is called Abelian gauge theory

Quantum field theory for which measurable quantities remain unchanged under a ‘group transformation’. All these theories consecutive field transformations do not commute. All non-Abelian gauge theories are based on work proposed by Yang and Mills in 1954, describe the interaction between two quantum fields of fermions. In which particles represented by fields whose normal modes of oscillation are quantized. Elementary particle interactions are described by relativistically invariant theories of quantized fields, ie., by relativistic quantum field theories. Gauge transformations can take the form of a simple multiplication by a constant phase. Such transformations are called ‘global gauge transformations’. In local gauge transformations, the phase of the fields is alterable by amounts that vary with space and time; i.e., Ψ ➝ eiθ ( χ ) Ψ, Where θ ( χ ) is a function of space-time. As, in Abelian gauge theories, consecutive field transformations commute, i.e.,

Ψ ➝ ei θ ( χ ) ei φ Ψ = ei φ ( χ ) ei φ ( χ ) Ψ,

Where φ (χ ) is another function of space and time. Quantum chromodynamics ( the theory of the strong interaction ) and electroweak and grand unified theories are all non-Abelian. In these theories consecutive field transformations do not commute. All non-Abelian gauge theories are based on work proposed by Yang and Mils, as Einstein’s theory of general relativity can also be formulated as a local gauge theory.

A symmetry including both boson and fermions, in theories based on super-symmetry every boson has a corresponding boson. Th boson partners of existing fermions have names formed by prefacing the names of the fermion with an “s” ( e.g., selection, squark, lepton ). The names of the fermion partners of existing bosons are obtained by changing the terminal -on of the boson to -into ( e.g., photons, gluons, and zino ). Although, super-symmetries have not been observed experimentally, they may prove important in the search for a Unified Field Theory of the fundamental interactions.

The quark is a fundamental constituent of hadrons, i.e., of particles that take part in strong interactions. Quarks are never seen as free particles, which is substantiated by lack of experimental evidence for isolated quarks. The explanation given for this phenomenon in gauge theory is known a quantum chromodynamics, by which quarks are described, is that quark interaction become weaker as they come closer together and fall to zero when the distance between them is zero. The converse of this proposition is that the attractive forces between quarks become stronger s they move, as this process has no limited, quarks can never separate from each other. In some theories, it is postulated that at very high-energy temperatures, as might have prevailed in the early universe, quarks can separate, te temperature at which this occurs is called the ‘deconfinement temperatures’. Nevertheless, their existence has been demonstrated in high-energy scattering experiments and by symmetries in the properties of observed hadrons. They are regarded s elementary fermions, with spin ½, baryon number ⅓, strangeness 0 or = 1, and charm 0 or + 1. They are classified I six flavours up (u), charm (c) and top (t), each with charge ⅔ the proton charge, down (d), strange (s) and bottom (b ), each with ‒ ⅓ the proton charge ]. Each type has an antiquark with reversed signs of charge, baryon number, strangeness, nd charm. The top quark has not been observed experimentally, but there are strong theoretical arguments for its existence. The top quark mass is known to be greater than about 90 GeV / c2.

The fractional charges of quarks are never observed in hadrons, since the quarks form combinations in which the sum of their charges is zero or integral. Hadrons can be either baryons or mesons, essentially, baryons are composed of three quarks while mesons are composed of a quark-antiquark pair. These components are bound together within the hadron by the exchange of particles known as gluons. Gluons are neutral massless gauge bosons, the quantum field theory of electromagnetic interactions discriminate themselves against the gluon as the analogue of the photon and with a quantum number known as ‘colour’ replacing that of electric charge. Each quark type ( or flavour ) comes in three colours ( red, blue and green, say ), where colour is simply a convenient label and has no connection with ordinary colour. Unlike the photon in quantum chromodynamics, which is electrically neutral, gluons in quantum chromodynamics carry colour and can therefore interact with themselves. Particles that carry colour are believed not to be able to exist in free particles. Instead, quarks and gluons are permanently confined inside hadrons (strongly interacting particles, such as the proton and the neutron).

The gluon self-interaction leads to the property known as ‘asymptotic freedom’, in which the interaction strength for th strong interaction decreases as the momentum transfer involved in an interaction increase. This allows perturbation theory to be used and quantitative comparisons to be made with experiment, similar to, but less precise than those possibilities of quantum chromodynamics. Quantum chromodynamics the being tested successfully in high energy muon-nucleon scattering experiments and in proton-antiproton and electron-positron collisions at high energies. Strong evidence for the existence of colour comes from measurements of the interaction rates for e+e‒ ➝ hadrons and e+e‒ ➝ μ+ μ‒. The relative rate for these two processes is a factor of three larger than would be expected without colour, this factor measures directly the number of colours, i.e., for each quark flavour.

The quarks and antiquarks with zero strangeness and zero charm are the u, d, û and . They form the combinations:

proton ( uud ), antiproton ( ūū )

neutron ( uud ), antineutron ( ū )

pion: π+ (u ), π‒ ( ūd ), π0 ( d, uū ).

The charge and spin of these particles are the sums of the charge and spin of the component quarks and/or antiquarks.

In the strange baryon, e.g., the Λ and Σ meons, either the quark or antiquark is strange. Similarly, the presence of one or more ‘c’ quarks leads to charmed baryons’ ‘a’ ‘c’ or ‘č’ to the charmed mesons. It has been found useful to introduce a further subdivision of quarks, each flavour coming in three colours ( red, green, blue ). Colour as used here serves simply as a convenient label and is unconnected with ordinary colour. A baryon comprises a red, a green, and a blue quark and a meson comprised a red and ant-red, a blue and ant-blue, or a green and antigreen quark and antiquark. In analogy with combinations of the three primary colours of light, hadrons carry no net colour, i.e., they are ‘colourless’ or ‘white’. Only colourless objects can exist as free particles. The characteristics of the six quark flavours are shown in the table.

The cental feature of quantum field theory, is that the essential reality is a set of fields subject to the rules of special relativity and quantum mechanics, all else is derived as a consequence of the quantum dynamics of those fields. The quantization of fields is essentially an exercise in which we use complex mathematical models to analyse the field in terms of its associated quanta. And material reality as we know it in quantum field theory is constituted by the transformation and organization of fields and their associated quanta. Hence, this reality

Reveals a fundamental complementarity, in which particles are localized in space/time, and fields, which are not. In modern quantum field theory, all matter is composed of six strongly interacting quarks and six weakly interacting leptons. The six quarks are called up, down, charmed, strange, top, and bottom and have different rest masses and functional changes. The up and own quarks combine through the exchange of gluons to form protons and neutrons.

The ‘lepton’ belongs to the class of elementary particles, and does not take part in strong interactions. They have no substructure of quarks and are considered indivisible. They are all; fermions, and are categorized into six distinct types, the electron, muon, and tauon, which are all identically charged, but differ in mass, and the three neutrinos, which are all neutral and thought to be massless or nearly so. In their interactions the leptons appear to observe boundaries that define three families, each composed of a charged lepton and its neutrino. The families are distinguished mathematically by three quantum numbers, Ie, Iμ, and Iv lepton numbers called ‘lepton numbers. In weak interactions their IeTOT, IμTOT and Iτ for the individual particles are conserved. In quantum field theory, potential vibrations at each point in the four fields are capable of manifesting themselves in their complemtarity, their expression as individual particles. And the interactions of the fields result from the exchange of quanta that are carriers of the fields. The carriers of the field, known as messenger quanta, are the ‘coloured’ gluons for the strong-binding-force, of which the photon for electromagnetism, the intermediate boson for the weak force, and the graviton or gravitation. If we could re-create the energies present in the fist trillionths of trillionths of a second in the life o the universe, these four fields would, according to quantum field theory, become one fundamental field.

The movement toward a unified theory has evolved progressively from super-symmetry to super-gravity to string theory. In string theory the one-dimensional trajectories of particles, illustrated in the Feynman lectures, seem as if, in at all were possible, are replaced by the two-dimensional orbits of a string. In addition to introducing the extra dimension, represented by a smaller diameter of the string, string theory also features another mall but non-zero constant, with which is analogous to Planck’s quantum of action. Since the value of the constant is quite small, it can be generally ignored except at extremely small dimensions. But since the constant, like Planck’s constant is not zero, this results in departures from ordinary quantum field theory in very small dimensions.

Part of what makes string theory attractive is that it eliminates, or ‘transforms away’, the inherent infinities found in the quantum theory of gravity. And if the predictions of this theory are proven valid in repeatable experiments under controlled coeditions, it could allow gravity to be unified with the other three fundamental interactions. But even if string theory leads to this grand unification, it will not alter our understanding of ave-particle duality. While the success of the theory would reinforce our view of the universe as a unified dynamic process, it applies to very small dimensions, and therefore, does not alter our view of wave-particle duality.

While the formalism of quantum physics predicts that correlations between particles over space-like inseparability, of which are possible, it can say nothing about what this strange new relationship between parts (quanta) and the whole (cosmos) cause to result outside this formalism. This does not, however, prevent us from considering the implications in philosophical terms. As the philosopher of science Errol Harris noted in thinking about the special character of wholeness in modern physics, a unity without internal content is a blank or empty set and is not recognizable as a whole. A collection of merely externally related parts does not constitute a whole in that the parts will not be “mutually adaptive and complementary to one-another.”

Wholeness requires a complementary relationship between unity and difference and is governed by a principle of organization determining the interrelationship between parts. This organizing principle must be universal to a genuine whole and implicit in all parts constituting the whole, even the whole is exemplified only in its parts. This principle of order, Harris continued, “is nothing really in and of itself. It is the way he parts are organized, and another constituent additional to those that constitute the totality.”

In a genuine whole, the relationship between the constituent parts must be “internal or immanent” ion the parts, as opposed to a more spurious whole in which parts appear to disclose wholeness dur to relationships that are external to the arts. The collection of parts that would allegedly constitute the whole in classical physics is an example of a spurious whole. Parts continue a genuine whole when the universal principle of order is inside the parts and hereby adjusts each to all so that they interlock and become mutually complementary. This not only describes the character of the whole revealed in both relativity theory and quantum mechanics. It is also consistent with the manner in which we have begun to understand the relations between parts and whole in modern biology.

Modern physics also reveals, claimed Harris, complementary relationship between the differences between parts that constitute and the universal ordering principle that are immanent in each part. While thje whole cannot be finally disclosed in the analysis of the parts, the study of the differences between parts provides insights into the dynamic structure of the whole present in each part. The part can never, however, be finally isolated from the web of relationships that discloses the interconnections with the whole, and any attempt to do so results in ambiguity.

Much of the ambiguity in attempts to explain the character of wholes in both physics and biology derives from the assumption that order exists between or outside parts. Yet order in complementary relationships between difference and sameness in any physical event is never external to that event, and the cognations are immanent in the event. From this perspective, the addition of non-locality to this picture of the distributive constitution in dynamic function of wholeness is not surprising. The relationships between part, as quantum event apparent in observation or measurement, and the undissectable whole, calculate on in but are not described by the instantaneous correlations between measurements in space-like separate regions, is another extension of the part-whole complementarity in modern physics.

If the universe is a seamlessly interactive system that evolves to higher levels of complex and complicating regularities of which ae lawfully emergent in property of systems, we can assume that the cosmos is a single significant whole that evinces progressive order in complementary relations to its parts. Given that this whole exists in some sense within all parts (quanta), one can then argue that in operates in self-reflective fashion and is the ground from all emergent plexuities. Since human consciousness evinces self-reflective awareness in te human brain (well protected between the cranium walls) and since this brain, like all physical phenomena, can b viewed as an emergent property of the whole, it is unreasonable to conclude, in philosophical terms at least, that the universe is conscious.

Nevertheless, since the actual character of this seamless whole cannot be represented or reduced to its parts, it lies, quite laterally, beyond all human representation or descriptions. If one chooses to believe that the universe be a self-reflective and self-organizing whole, this lends no support whatsoever to conceptual representation of design, meaning, purpose, intent, or plan associated with mytho-religious or cultural heritage. However, if one does not accept this view of the universe, there is noting in the scientific description of nature that can be used to refute this position. On the other hand, it is no longer possible to argue that a profound sense of unity with the whole, which has long been understood as foundation of religious experiences, but can be dismissed, undermined, or invalidated with appeals to scientific knowledge.

While we have consistently tried to distinguish between scientific knowledge and philosophical speculation based on this of what is obtainable, let us be quite clear on one point -there is no empirically valid causal linkage between the former and the latter. Those who wish to dismiss the speculative base on which is obviously free to do as done. However, there is another conclusion to be drawn, in that is firmly grounded in scientific theory and experiment there is no basis in the scientific descriptions of nature for believing in the radical Cartesian division between mind and world sanctioned by classical physics. Clearly, his radical separation between mind and world was a macro-level illusion fostered by limited awareness of the actual character of physical reality nd by mathematical idealizations extended beyond the realms of their applicability.

Nevertheless, the philosophical implications might prove in themselves as a criterial motive in debative consideration to how our proposed new understanding of the relationship between parts and wholes in physical reality might affect the manner in which we deal with some major real-world problems. This will issue to demonstrate why a timely resolution of these problems is critically dependent on a renewed dialogue between members of the cultures of human-social scientists and scientist-engineers. We will also argue that the resolution of these problems could be dependent on a renewed dialogue between science and religion.

As many scholars have demonstrated, the classical paradigm in physics has greatly influenced and conditioned our understanding and management of human systems in economic and political realities. Virtually all models of these realities treat human systems as if they consist of atomized units or parts that interact with one another in terms of laws or forces external to or between the parts. These systems are also viewed as hermetic or closed and, thus, its discreteness, separateness and distinction.

Consider, for example, how the classical paradigm influenced or thinking about economic reality. In the eighteenth and nineteenth centuries, the founders of classical economics -figures like Adam Smith, David Ricardo, and Thomas Malthus conceived of the economy as a closed system in which intersections between parts (consumer, produces, distributors, etc.) are controlled by forces external to the parts (supply and demand). The central legitimating principle of free market economics, formulated by Adam Smith, is that lawful or law-like forces external to the individual units function as an invisible hand. This invisible hand, said Smith, frees the units to pursue their best interests, moves the economy forward, and in general legislates the behaviour of parts in the best vantages of the whole. (The resemblance between the invisible hand and Newton’s universal law of gravity and between the relations of parts and wholes in classical economics and classical physics should be transparent.)

After roughly 1830, economists shifted the focus to the properties of the invisible hand in the interactions between pats using mathematical models. Within these models, the behaviour of pats in the economy is assumed to be analogous to the awful interactions between pats in classical mechanics. It is, therefore, not surprising that differential calculus was employed to represent economic change in a virtual world in terms of small or marginal shifts in consumption or production. The assumption was that the mathematical description of marginal shifts n the complex web of exchanges between parts (atomized units and quantities) and whole (closed economy) could reveal the lawful, or law-like, machinations of the closed economic system.

These models later became one of the fundamentals for microeconomics. Microeconomics seek to describe interactions between parts in exact quantifiable measures -such as marginal cost, marginal revenue, marginal utility, and growth of total revenue as indexed against individual units of output. In analogy with classical mechanics, the quantities are viewed as initial conditions that can serve to explain subsequent interactions between parts in the closed system in something like deterministic terms. The combination of classical macro-analysis with micro-analysis resulted in what Thorstein Veblen in 1900 termed neoclassical economics -the model for understanding economic reality that is widely used today

Beginning in the 1939s, the challenge became to subsume the understanding of the interactions between parts in closed economic systems with more sophisticated mathematical models using devices like linear programming, game theory, and new statistical techniques. In spite of the growing mathematical sophistication, these models are based on the same assumptions from classical physics featured in previous neoclassical economic theory -with one exception. They also appeal to the assumption that systems exist in equilibrium or in perturbations from equilibria, and they seek to describe the state of the closed economic system in these terms.

One could argue that the fact that our economic models are assumptions from classical mechanics is not a problem by appealing to the two-domain distinction between micro-level macro-level processes expatiated upon earlier. Since classical mechanic serves us well in our dealings with macro-level phenomena in situations where the speed of light is so large and the quantum of action is so small as to be safely ignored for practical purposes, economic theories based on assumptions from classical mechanics should serve us well in dealing with the macro-level behaviour of economic systems.

The obvious problem, . . . acceded peripherally, . . . nature is relucent to operate in accordance with these assumptions, in that the biosphere, the interaction between parts be intimately related to the hole, no collection of arts is isolated from the whole, and the ability of the whole to regulate the relative abundance of atmospheric gases suggests that the whole of the biota appear to display emergent properties that are more than the sum of its parts. What the current ecological crisis reveals in the abstract virtual world of neoclassical economic theory. The real economies are all human activities associated with the production, distribution, and exchange of tangible goods and commodities and the consumption and use of natural resources, such as arable land and water. Although expanding economic systems in the really economy ae obviously embedded in a web of relationships with the entire biosphere, our measure of healthy economic systems disguises this fact very nicely. Consider, for example, the healthy economic system written in 1996 by Frederick Hu, head of the competitive research team for the World Economic Forum -short of military conquest, economic growth is the only viable means for a country to sustain increases in natural living standards . . . An economy is internationally competitive if it performs strongly in three general areas: Abundant productive inputs from capital, labour, infrastructure and technology, optimal economic policies such as low taxes, little interference, free trade and sound market institutions. Such as the rule of law and protection of property rights.

The prescription for medium-term growth of economies ion countries like Russia, Brazil, and China may seem utterly pragmatic and quite sound. But the virtual economy described is a closed and hermetically sealed system in which the invisible hand of economic forces allegedly results in a health growth economy if impediments to its operation are removed or minimized. It is, of course, often trued that such prescriptions can have the desired results in terms of increases in living standards, and Russia, Brazil and China are seeking to implement them in various ways.

In the real economy, however, these systems are clearly not closed or hermetically sealed: Russia uses carbon-based fuels in production facilities that produce large amounts of carbon dioxide and other gases that contribute to global warming: Brazil is in the process of destroying a rain forest that is critical to species diversity and the maintenance of a relative abundance of atmospheric gases that regulate Earth temperature, and China is seeking to build a first-world economy based on highly polluting old-world industrial plants that burn soft coal. Not to forget, . . . the victual economic systems that the world now seems to regard as the best example of the benefits that can be derived form the workings of the invisible hand, that of the United States, operates in the real economy as one of the primary contributors to the ecological crisis.

In “Consilience,” Edward O. Wilson makes to comment, the case that effective and timely solutions to the problem threatening human survival is critically dependent on something like a global revolution in ethical thought and behaviour. But his view of the basis for this revolution is quite different from our own. Wilson claimed that since the foundations for moral reasoning evolved in what he termed ‘gene-culture’ evolution, the rules of ethical behaviour re emergent aspects of our genetic inheritance. Based on the assumptions that the behaviour of contemporary hunter-gatherers resembles that of our hunter-gatherers forebears in the Palaeolithic Era, he drew on accounts of Bushman hunter-gatherers living in the centre Kalahari in an effort to demonstrate that ethical behaviour is associated with instincts like bonding, cooperation, and altruism.

Wilson argued that these instincts evolved in our hunter-gatherer accessorial descendabilities, whereby genetic mutation and the ethical behaviour associated with these genetically based instincts provided a survival advantage. He then claimed that since these genes were passed on to subsequent generations of our dependable characteristics, which eventually became pervasive in the human genome, the ethical dimension of human nature has a genetic foundation. When we fully understand the “innate epigenetic rules of moral reasoning,” it seems probable that the rules will probably turn out to be an ensemble of many algorithms whose interlocking activities guide the mind across a landscape of nuances moods and choices.

Any reasonable attempt to lay a firm foundation beneath the quagmire of human ethics in all of its myriad and often contradictory formulations is admirable, and Wilson’s attempt is more admirable than most. In our view, however, there is little or no prospect that I will prove successful for a number of reasons. Wile te probability for us to discover some linkage between genes and behaviour, seems that the lightened path of human ethical behaviour and ranging advantages of this behaviour is far too complex, not o mention, inconsistently been reduced to a given set classification of “epigenetic ruled of moral reasoning.”

Also, moral codes may derive in part from instincts that confer a survival advantage, but when we are t examine these codes, it also seems clear that they are primarily cultural products. This explains why ethical systems are constructed in a bewildering variety of ways in different cultural contexts and why they often sanction or legitimate quite different thoughts and behaviours. Let us not forget that rules f ethical behaviours are quite malleable and have been used to sacredly legitimate human activities such as slavery, colonial conquest, genocide and terrorism. As Cardinal Newman cryptically put it, “Oh how we hate one another for the love of God.”

According to Wilson, the “human mind evolved to believe in the gods” and people “need a sacred narrative” to his view are merely human constructs and, therefore, there is no basis for dialogue between the world views of science and religion. “Science for its part, will test relentlessly every assumption about the human condition and in time uncover the bedrock of the moral and religiously sentient. The eventual result of the competition between the two world view, is believed, as I, will be the secularization of the human epic and of religion itself.

Wilson obviously has a right to his opinions, and many will agree with him for their own good reasons, but what is most interesting about his thoughtful attempted to posit a more universal basis for human ethics in that it s based on classical assumptions about the character of both physical and biological realities. While Wilson does not argue that human’s behaviour is genetically determined in the strict sense, however, he does allege that there is a causal linkage between genes and behaviour that largely condition this behaviour, he appears to be a firm believer in classical assumption that reductionism can uncover the lawful essences that principally govern the physical aspects attributed to reality, including those associated with the alleged “epigenetic rules of moral reasoning.”

Once, again, Wilson’s view is apparently nothing that cannot be reduced to scientific understandings or fully disclosed in scientific terms, and this apparency of hope for the future of humanity is that the triumph of scientific thought and method will allow us to achieve the Enlightenments ideal of disclosing the lawful regularities that govern or regulate all aspects of human experience. Hence, science will uncover the “bedrock of moral and religious sentiment, and the entire human epic will be mapped in the secular space of scientific formalism.” The intent is not to denigrate Wilson’s attentive efforts to posit a more universal basis for the human condition, but is to demonstrate that any attempt to understand or improve upon the behaviour based on appeals to outmoded classical assumptions is unrealistic and outmoded. If the human mind did, in fact, evolve in something like deterministic fashion in gene-culture evolution - and if there were, in fact, innate mechanisms in mind that are both lawful and benevolent. Wilson’s program for uncovering these mechanisms could have merit. But for all th reasons that have been posited, classical determinism cannot explain the human condition and its evolutionary principle that govern in their functional dynamics, as Darwinian evolution should be modified to accommodate the complementary relationships between cultural and biological principles that governing evaluations do indeed have in them a strong, and firm grip upon genetical mutations that have attributively been the distribution in the contribution of human interactions with themselves in the finding to self-realizations and undivided wholeness.

Equally important, the classical assumption that the only privileged or valid knowledge is scientific is one of the primary sources of the stark division between the two cultures of humanistic and scientists-engineers, in this view, Wilson is quite correct in assuming that a timely end to the two culture war and a renewer dialogue between members of these cultures is now critically important to human survival. It is also clear, however, that dreams of reason based on the classical paradigm will only serve to perpetuate the two-culture war. Since these dreams are also remnants of an old scientific word view that no longer applies in theory in fact, to the actual character of physical reality, as reality is a probable service to frustrate the solution for which in found of a real world problem.

However, there is a renewed basis for dialogue between the two cultures, it is believed as quite different from that described by Wilson. Since classical epistemology has been displaced, or is the process of being displaced, by the new epistemology of science, the truths of science can no longer be viewed as transcendent ad absolute in the classical sense. The universe more closely resembles a giant organism than a giant machine, and it also displays emergent properties that serve to perpetuate the existence of the whole in both physics and biology that cannot be explained in terms of unrestricted determinism, simple causality, first causes, linear movements and initial conditions. Perhaps the first and most important precondition for renewed dialogue between the two cultural conflicting realizations as Einstein explicated upon its topic as, that a human being is a “part of the whole.’ It is this spared awareness that allows for the freedom, or existential choice of self-decision of choosing our free-will and the power to differentiate a direct cars to free ourselves of the “optical illusion”of our present conception of self as a “part limited in space and time” and to widen “our circle of compassion to embrace al living creatures and the whole of nature in its beauty.” Yet, one cannot, of course, merely reason oneself into an acceptance of this view, nonetheless, the inherent perceptions of the world are reason that the capacity for what Einstein termed “cosmic religious feedings.” Perhaps, our enabling capability for that which is within us to have the obtainable ability to enabling of ours is to experience the self-realization, that of its realness is to sense its proven existence of a sense of elementarily leaving to some sorted conquering sense of universal consciousness, in so given to arise the existence of the universe, which really makes an essential difference to the existence or its penetrative spark of awakening indebtednesses of reciprocality?

Those who have this capacity will hopefully be able to communicate their enhanced scientific understanding of the relations among all aspects, and in part that is our self and the whole that are the universe in ordinary language wit enormous emotional appeal. The task lies before the poets of this renewing reality have nicely been described by Jonas Salk, which “man has come to the threshold of a state of consciousness, regarding his nature and his relationship to the Cosmos, in terms that reflects “reality.” By using the processes of Nature and metaphor, to describe the forces by which it operates upon and within Man, we come as close to describing “reality” as we can within te limits of our comprehension. Men will be very uneven in their capacity or such understanding, which, naturally, differs for different ages and cultures, and develops and changes over the course of time. For these reasons it will always be necessary to use metaphorical and mythical provisions as comprehensive guides to living. In this way. Man’s afforded efforts by the imagination and intellect can be playing the vital roles embarking upon the survival and his endurable evolution.

It is time, if not, only, concluded from evidence in its suggestive conditional relation, for which the religious imagination and the religious experience to engage upon the complementary truths of science in fitting that silence with meaning, as having to antiquate a continual emphasis, least of mention, that does not mean that those who do not believe in the existence of God or Being, should refrain in any sense from assessing the impletions of the new truths of science. Understanding these implications does not necessitate any ontology, and is in no way diminished by the lack of any ontology. And one is free to recognize a basis for a dialogue between science and religion for the same reason that one is free to deny that this basis exists -there is nothing in our current scientific world view that can prove the existence of God or Being and nothing that legitimate any anthropomorphic conceptions of the nature of God or Being. The question of belief in some ontology yet remains in what it has always been -a question, and the physical universe on the most basic level remains what it always been a riddle. And the ultimate answer to the question and the ultimate meaning of the riddle is, and probably always will be, a matter of personal choice and conviction.

The present time is clearly a time of a major paradigm shift, but consider the last great paradigm shift, the one that resulted in the Newtonian framework. This previous paradigm shift was profoundly problematic for the human spirit, it led to the conviction that we are strangers, freaks of nature, conscious beings in a universe that is almost entirely unconscious, and that, since the universe its strictly deterministic, even the free will we feel in regard to the movements of our bodies is an illusion. Yet it was probably necessary for the Western mind to go through the acceptance of such a paradigm.

The overwhelming success of Newtonian physics led most scientists and most philosophers of the Enlightenment to rely on it exclusively. As far as the quest for knowledge about reality was concerned, they regarded all of the other mode’s of expressing human experience, such as accounts of numinous emergences, poetry, art, and so on, as irrelevant. This reliance on science as the only way to the truth about the universe s clearly obsoletes. Science has to give up the illusion of its self-sufficiency and self-sufficiency of human reason. It needs to unite with other modes of knowing, n particular with contemplation, and help each of us move to higher levels of being and toward the Experience of Oneness.

If this is indeed the direction of the emerging world-view, then the paradigm shifts we are presently going through will prove to be nourishing to the human spirit and in correspondences with its deepest conscious or unconscious yearning -the yearning to emerge out of Plato’s shadows and into the light of luminosity.

Ideas began with Plato, as eternal mind-independent forms or archetypes of the things in the material world. Neoplatonism made them thoughts in the mind of God who created the world. The much criticized ‘new way of ideas’, so much a part of seventeenth and eighteenth-century philosophy, began with Descartes’ consciousable extension of ‘idea’ to cover whatever is in human minds too, an extension of which Locke made much use. But are they like mental images, of things outside the mind: Or non-representational, like sensations? If representational are they mental objects, standing between the mind and what they represent, or are they acts and modifications of a mind perceiving the world directly? Yet, are they neither objects nor acts, but dispositions? Malebranche and Arnauld (and then Leibniz) famously disagreed about how ‘ideas’ should be understood, and recent scholars disagree about how Arnauld, Descartes, Locke and Malebranche in fact understood them.

Although given to rise of many problems of especially of interpretation, but narrative descriptions define a space of philosophical problems. Nonetheless, ‘ideas’ are that with which we think, or in Locke’s terms, whatever the mind may be employed about in thinking. Looked at that way, they seem to be inherently transient, fleeting and unstable private presences. What is more, that ideas provide the way in which objective knowledge can be expressed. They are the essential components of understanding, and any intelligible proposition that is true must be capable of being understood. Plato’s theory of ‘forms’ is a launching celebration of the objective and timeless existence of ideas as concepts, and reified to the point where they make up the only real world, of separate and perfect models of which the empirical world is only a poor cousin. This doctrine, notable in the Timaeus, opened the way for the Neoplatonic notion pf idea as the thoughts of God. The concept gradually lost this other-worldly aspect, until after Descartes ideas become assimilated to whatever it is that lies in the mind of any thinking being.

Nonetheless, ideas give rise to many problems of interpretation, but between them they define a space of philosophical problems. Ideas are that with which we think, or in Locke’s terms, whatever the mind may be employed about in thinking. Looked at that way, they seem to be inherently transient, fleeting, and unstable private presences. Ideas provide the way in which objective knowledge can be expressed. They are the essential components of understanding, and any intelligible proposition that is true must be capable of being understood. Plato’s theory of ‘forms’ is a launching celebration of the objective and timeless existence of ideas as concepts, and reified to the point where they make up the only real world, of separate and perfect models of which the empirical world is only a poor cousin. This doctrine, notably in the ‘Timaeus’, opened the way for the Neoplatonic notion of ideas as the thoughts of God. The concept gradually lost this other-worldly aspect, until after Descartes ideas become assimilated to whatever it is that lies in the mind of any thinking being.

Together with a general bias toward the sensory, so that what lies in the mind may be thought of as something like images, and a belief that thinking is well explained as the manipulation having no real existence but existing in a fancied imagination. It is not reason but ‘the imagination’ that is found to be responsible for our making the empirical inferences that we do. There are certain general ‘principles of the imagination’ according to which ideas naturally come and go in the mind under certain conditions. It is the task of the ‘science of human nature’ to discover such principles, but without itself going beyond experience. For example, an observed correlation between things of two kinds can be seen to produce in everyone a propensity to expect a thing to the second sort given an experience of a thing of the first sort. We get a feeling, or an ‘impression’, when the mind makes such a transition and that is what leads us to attribute necessarily to the reflation between things of the two kinds, there is no necessity in the relations between things that happen in the world, but, given our experience and the way our minds naturally work, we cannot help thinking that there is.

A similar appeal to certain ‘principles of the imagination’ is what explains our belief in a world of enduring objects. Experience alone cannot produce that belief, everything we directly perceive is ‘momentary and fleeting’. And whatever our experience is like, no reasonable reservation could ensure us the existence of something independent of our impressions, which continues to exist when they cease. The series of our constantly changing sense impressions presents us with observable features which Hume calls ‘constancy ‘ and ‘coherence’, and these naturally operate on the mind in such a way as eventually to produce ‘the opinion of a continued and distinct existence’. The explanation is complicated, but it is meant to appeal only to psychological mechanisms which can be discovered by ‘careful and exact experiments, and the observation of those particular effects, which result from [the mind’s] different circumstances and situations’.

We believe not only in bodies, but also in persons, or selves, which continue to exist through time, and this belief too can be explained only by the operation of certain ‘principles of the imagination’. We never directly perceive anything we can call ourselves: The most we can be aware of in ourselves are our constantly changing momentary perceptions, not the mind or self which has them. For Hume, there is nothing that really binds the different perceptions together, we are led into the ‘fiction’ that they form a unity only because of the way in which the thought of such series of perceptions works upon the mind. ‘The mind is a kind of theatre, where several perceptions successively make their appearance, . . . there is properly no simplicity in it at one time, nor identity in different: Whatever natural propensity we may have to imagine that simplicity and identity. The comparison of the theatre must not mislead us. They are the successive perceptions only, that constitutes the mind.

Leibniz’s held, in opposition to Descartes, that adult humans can have experiences of which they are unaware: Experiences of which effect what they do, but which are not brought to self-consciousness. Yet there are creatures, such as animals and babies, which completely lack the ability to reflect of their experiences, and to become aware of them as experiences of theirs. The unity of a subject’s experience, which stems from his capacity to recognize all his experience as his, was dubbed by Kant ‘the transcendental unity of apperception ~ Leibniz’s term for inner awareness or self-consciousness. In contrast with ‘perception’ or outer awareness ~. However, this apprehension of unity is transcendental, than empirical, because it is presupposed in experience and cannot be derived from it. Kant used the need for this unity as the basis of his attempted refutation of scepticism about the external world. He argued that my experiences could only be united in self-consciousness if at least some of them were experiences of a law-governed world of objects in space. Outer experience is thus a necessary condition of inner awareness.

Here we seem to have a clear case of ‘introspection’, derived from the Latin ‘intro’ (within) + ‘specere’ (to look), introspection is the attention the mind gives to itself or to its own operations and occurrences. I can know there is a fat hairy spider in my bath by looking there and seeing it. But how do I know that I am seeing it rather than smelling it, or that my attitude to it is one of disgust than delight? One indistinct interpretation is to consider that: By a subsequent introspective act of ‘looking within’ and implementation to the psychological state ~ my seeing the spider. Introspection, therefore, is a mental occurrence, which, has as its object, some other psychological state like perceiving, desiring, willing, feeling, etc. In being a distinct awareness-episode it is different from a greater or higher degree to what is expected in the ordinary or naturalized course of events of belonging or what is typically a general ‘self-consciousness’ which characterizes all or some of our mental history.

The awareness generated by an introspective act can have varying degrees of complexity. It might be a simple knowledge of (mental) things’ ~ such as a particular perception-episode, or it might be the more complex knowledge of truths about one’s own mind. In this latter full-blown judgement form, introspection is usually the self-ascription of psychological properties and, when linguistically expressed, results in statements like ‘I am watching the spider’ or ‘I am repulsed’.

In psychology this deliberate inward look becomes a scientific method when it is ‘directed toward answering questions of theoretical importance for the advancement of our systematic knowledge of the laws and conditions of mental processes’. In philosophy, introspection (sometimes also called ‘reflection’) remains simply ‘that notice which mind takes of its own operations and has been used to serve the following important functions:

(1) Methodological: Thought experiments are a powerful tool in philosophical investigation. The Ontological Argument, for example, asks us to try to think of the most perfect being as lacking existence and Berkeley’s Master Argument challenges us to conceive of an unseen tree, conceptual results are then drawn from our failure or success. From such experiments to work, we must not only have (or fail to have) the relevant conceptions but also know that we have (or fail to have) them ~ presumably by introspection.

(2) Metaphysical: A metaphysical of mind needs to take cognizance of introspection. One can argue for ‘ghostly’ mental entities for ‘qualia’, for ‘sense-data’ by claiming introspective awareness of them. First-person psychological reports can have special consequences for the nature of persons and personal identity: Hume, for example, was content to reject the notion of a soul-substance because he failed to find such a thing by ‘looking within’. Moreover, some philosophers argue for the existence of additional perspectival facts ~ the fact of ‘what it is like’ to be the person I am or to have an experience of such-and-such-a-kind. Introspection as our access to such facts becomes important when we construct a complete metaphysic of the world.

(3) Epistemological: Surprisingly, the most important use made of introspection has been in an accounting for our knowledge of the outside world. According to a foundationalist theory of justification an empirical belief is either basic and ‘self-justifying’ or justified in relation to basic beliefs. Basic beliefs therefore, constitute the rock-bottom of all justification and knowledge. Now introspective awareness is said to have a unique epistemological status in it, we are said to achieve the best possibly epistemological position and consequently, introspective beliefs and thereby constitute the foundation of all justification.

Coherence is a major player in the theatre of knowledge. There are coherence theories of belief, truth and justification where these combine in various ways to yield theories of knowledge, coherence theories of belief are concerned with the content of beliefs. Consider a belief you now have, the belief that you are reading a page in a book. So what makes that belief the belief that it is? What makes it the belief that you are reading a page in a book than the belief that you have something other of a preoccupation? The same stimuli may produce various beliefs and various beliefs may produce the same action. The role that gives the belief the content it has is the role it plays within a network of relations to other beliefs, the role in inference and implication, for example, I infer different things from believing that I am reading a page in a book than from any other belief, just as I infer that belief from different things than I refer other beliefs from.

The input of perception and the output of an action supplement the central role of the systematic relations the belief has to other beliefs, but the systematic relations give the belief the special content it has. They are the fundamental source of the content of beliefs. That is how coherence comes to be. A belief that the content that it does because of the away in which it coheres within the system of beliefs, however, weak coherence theories affirm that coherence is one determinant of the content of belief as strong coherence theories on the content of belief affirm that coherence is the sole determinant of the content of belief.

Nonetheless, the concept of the given-referential immediacy as apprehended of the contents of sense experience is expressed in the first person, and present tense reports of appearances. Apprehension of the given is seen as immediate both in a causal sense, since it lacks the usual causal chain involved in perceiving real qualities of physical objects, and in an epistemic sense, since judgements expressing it are justified independently of all other beliefs and evidence. Some proponents of the idea of the ‘given’ maintain that its apprehension is absolutely certain: Infallible, incorrigible and indubitable. It has been claimed also that a subject is omniscient with regard to the given ~ if a property appears, then the subject knows this.

Without some independent indication that some of the beliefs within a coherent system are true, coherence in itself is no indication of truth. Fairy stories can cohere, however, our criteria for justification must indicate to us the probable truth of our beliefs. Hence, within any system of beliefs there must be some privileged class with which others must cohere to be justified. In the case of empirical knowledge, such privileged beliefs must represent the point of contact between subject and world: They must generate or impose of a set up, if only to bring into existence, the perceptions that when challenged, however, we justify our ordinary perceptual beliefs about physical properties by appeal to beliefs about appearances. The latter seem more suitable as foundational, since there is no class of more certain perceptual beliefs to which we appeal for their justification.

The argument that foundations must be certain was offered by Lewis (1946). He held that no proposition can be probable unless some are certain. If the probability of all propositions or beliefs were relative to evidence expressed in others, and if these relations were linear, then any regress would apparently have to terminate in propositions or beliefs that are certain. But Lewis shows neither that such relations must be linear nor that redresses cannot terminate in beliefs that are merely probable or justified in themselves without being certain or infallible.

Arguments against the idea of the given originate with Kant (1724-1804), who argues that percepts without concepts do not yet constitute any form of knowing. Being non-epistemic, they presumably cannot serve as epistemic foundations. Once we recognize that we must apply concepts of properties to appearances and formulate beliefs utilizing those concepts before the appearances can play any epistemic role, it becomes more plausible that such beliefs are fallible. The argument was developed by Wilfrid Sellars (1963), which according to him, the idea of the given involves a confusion between sensing particulars (having sense impressions), which is non-epistemic, and having non-inferential knowledge of propositions referring to appearances. The former may be necessary for acquiring perceptual knowledge, but it is not itself a primitive kind of knowing. Its being non-epistemic renders it immune from error, but also unsuitable for epistemological foundations. The latter, non-referential perceptual knowledge, are fallible, requiring concepts acquired through trained responses to public physical objects.

Contemporary foundationalist’s deny the coherentist’s claim whole eschewing the claim that foundations, in the form of reports about appearances, are infallible. They seek alternatives to the given as foundations. Although arguments against infallibility are sound, other objections to the idea of foundations are not. That concepts of objective properties are learned prior to concepts of appearances, for example, implied neither that claims about appearances are less certain than claims about objective properties, nor that the latter are prior in chains of justification. That there can be no knowledge prior to the acquisition and consistent application of concepts allows for propositions whose truth requires only consistent applications of concepts, and this may be so for some claims about appearances, least of mention, coherentists would add that such genuine belief’s stands in need of justification themselves and so cannot be foundations.

Coherentists will claim that a subject requires evidence that he applies concepts consistently that he is able, for example, consistently to distinguish red from other colours that appear. Beliefs about red appearances could not then be justified independently of other beliefs expressing that evidence. To say that part of the doctrine of the given that holds beliefs about appearances to be self-justified, we require an account of how such justification is possible, how some beliefs about appearances can be justified without appeal to evidence. Some foundationalists simply assert such warrant as derived from experience, but, unlike appeals to certainty by proponents of the given.

It is, nonetheless, an explanation of this capacity that enables its developments as an epistemological corollary into an essential metaphysical dualism. The world of ‘matter’ is known through external/outer sense-perception. So cognitive access to ‘mind’ must be based on a parallel process of introspection which ‘thought . . . not ‘sense’, as having nothing to do with external objects: Yet [put] is very like it, and might properly enough be called ‘internal sense’. However, having mind as object, is not sufficient to make a way of knowing ‘inner’ in the relevant sense be because mental facts can be grasped through sources other than introspection. To point, is significantly given in somewhat of a tenable provision in the giving validation for the manifested implications are that some ‘inner perceptions’ provide a kind of access to the mental not obtained otherwise ~ it is a ‘look within from within’. Stripped of metaphor this indicates the following epistemological features:

1. Only I can introspect my mind.

2. I can introspect only my mind.

3. Introspective awareness is superior to any other knowledge of contingent facts that I or others might have.

(1) and (2) are grounded in the Cartesian of ‘privacy’ of the mental. Normally, a single object can be perceptually or inferentially grasped by many subjects, just as the same subject can perceive and infer different things. The epistemic peculiarity of introspection is that, is, is exclusive ~ it gives knowledge only of the mental history of the subject introspecting.

The tenet (2) of the traditional theory is grounded in the Cartesian idea of ‘privileged access’. The epistemic superiority of introspection lies in its being and infallible source of knowledge. First-person psychological statements which are its typical results cannot be mistaken. This claim is sometimes supported by an ‘imaginability test’, e.g., the impossibility of imaging that I believe that I am in pain, while at the same time imaging evidence that I am not in pain. An apparent counter-example to this infallibility claim would be the introspective judgement ‘I am perceiving a dead friend’ when I am really hallucinating. This is taken to by reformulating such introspective reports as ‘I seem to be perceiving a dead friend’. The importance of such privileged access is that introspection becomes a way of knowing immune from the pitfalls of other sources of cognition. The basic asymmetry between first and third person psychological statements by introspective and non-introspective methods, but even dualists can account for introspective awareness in different ways:

(1) Non-perceptual models ~ Self-scrutiny need not be perceptual. My awareness of an object ‘O’ changes the status of ‘O’. It now acquires the property of ‘being an object of awareness’. On the basis of this or the fact that I am aware of ‘O’, such an ‘inferential model’ of awareness is suggested by the Bhatta Mimamsa school of Indian Epistemology. This view of introspection does not construe it as a direct awareness of mental operations but, interestingly, we will have occasion to refer to theories where the emphasis on directness itself leads to a non-perceptual, or at least, a non-observational account of introspection.

(2) Reflexive models ~ Epistemic access to our minds need not involve a separate attentive act. Part of the meaning of a conscious state is that I know in that state when I am in that state. Conscious perception is here conceived as an awareness of ‘phosphorescence’ attached to some mental occurrence and in no need of a subsequent illustration to reveal itself. Of course, if introspection is defined as a distinct act then reflexive models are really accounts of the first-person access that makes no appeal to introspection.

(3) Public-mind theories and fallibility/infallibility models ~ the physicalists’ denial of metaphysically private mental facts naturally suggests that ‘looking within’ is not merely like perception but is perception. For Ryle (1900-76). Mental states are ‘iffy’ behavioural facts which, in principle, are equally accessible to everyone by the same means: One’s own self-awareness therefore is, in effect, no different in type from anyone else’s observations about one’s mind.

A more interesting move is for the physicalists to retain the truism that I grasp that I am sad in a very different way from that in which I know you to be sad. This directedness or non-inferential nature of self-knowledge can be preserved in some physicalists theories of introspection. For instance, Armstrong’s identification of mental states with causes of bodily behaviour and of the latter with brain states, makes introspection the process of acquiring information about such inner physical causes. But since introspection is itself a mental state, it is a process in the brain as well: And since its grasp of the relevant causal information is direct, it becomes a process in which the brain scans itself. Alternatively, a broadly ‘functionalist’ view of mental states suggest of the machine-analogue of the introspective situation: A machine-table with the instruction ‘Print: ‘I am in state A’ when in state ‘A’, results in the output ‘I am in state A’ when expounds the ‘view of mental states that views of mental states suggest’ occurs. Similarly, if we define mental states and events functionally, we can say that introspection occurs when an occurrence of a mental state ‘M’ directly results in awareness of ‘M’. Observe with care that this way of emphasizing directness yields a non-perceptual and non-observational model of introspection. The machine in printing ‘I am positioned in state A’, (when it is not making a ‘verbal mistake’) just because it is in state ‘A’. There is no computation of information or process of ascertaining involved. The latter, at best, consist simply in passing through a sequence of states.

Furthering towards the legitimate question: How do I know that I am seeing a spider? Was interpreted as a demand for the faculty or information-processing-mechanism whereby I come to acquire this knowledge? Peculiarities of first-person psychological awareness and reports were carried over as peculiarities of this mechanism. However, the question need not demand the search for a method of knowing but rather for an explanation of the special epistemic features of first-person psychological statements. In that, the problem of introspection (as a way of knowing) dissolves but the problem of explaining ‘introspective’ or first-person authority remains.

Traditionally, belief has been of epistemological interest in its propositional guise: ‘S’ believes that ‘p’, where ‘p’ is a proposition towards which an agent, ‘S’, exhibits an attitude of acceptance. Not all belief is of this sort. If I trust what you say, I believe you. And someone may believe in Mrs. Collins, or in a free-market economy, or in God. It is sometimes supposed that all beliefs are ‘reducible’ to propositional belief, belief-that. Thus, my believing you might be thought as matter of my believing, perhaps, that what you say is true, and your belief in free markets or in God, a matter of your believing that free-market economies are desirable or that God exists.

It is doubtful, however, that non-propositional believing can, in every case, be reduced in this way. Debated on this point has tended to focus on an apparent distinction between ‘belief-that’ and ‘belief-in’, and the application of this distinction to belief in God: St. Thomas Aquinas (1225-64), accepted or advanced as true or real on the basis of less than convincing evidence in supposing that to believe in God is simply to believe that certain truths hold, such that God exists, that he is benevolent, etc. Others ague that belief-in is a distinctive attitude, one that includes essentially an element of trust. More commonly, belief-in has been taken to involve a combination of propositional belief together with some further attitude.

H.H. Price (1969) defends the claim that there is different sorts of belief-in, some, but not all, reducible to beliefs-that. If you believe in God, you believe that God exists, that God is good, etc. But, according to Price, your belief involves, in addition, a certain complex pro-attitude toward its object. One might attempt to analyse this further attitude in terms of additional beliefs-that: ‘S’ believes in ‘χ’ exists (and perhaps holds further factual beliefs about ‘χ’) (2) ‘S’ believes that ‘χ; is good or valuable in some respect? ; and (3) ‘S’ believes that χ’s being good or valuable in this respect is it is a good thing. An analysis of this sort, however, fails adequately to capture the further affective component of belief-in. Thus, according to Price, if you believe in God, your belief is merely that certain truths hold: You possess, in addition, an attitude of commitment and trust towards God.

An “idea”, actually exists in the mind as a product of mental activity. Human history is in essence a history of ideas, as thoughts are distinctly intellectual and stresses contemplation and reasoning. Justly as language is the dress of thought. Ideas began with Plato, as eternal, mind-independent forms or archetypes of the things in the material world. Neoplatonism made them thoughts in the mind of God who created the world. The much criticized ‘new way of ideas’, so much a part of seventeenth and eighteenth-century philosophy, began with Descartes’ (1596-1650) conscionable extension of ideas to cover whatever is in human minds too, an extension of which Locke (1632-1704) made much use. But are they like mental images, of things outside the mind, or non-representational, like sensations? If representational, are they mental objects, standing between the mind and what they represent, or are they mental acts and modifications of a mind perceiving the world directly? Finally, are they neither objects nor mental acts, but dispositions? Malebranche (1632-1715) and Arnauld (1612-94), and then Leibniz, famously disagreed about how ‘ideas’ should be understood, and recent scholars disagree about how Arnauld, Descartes, Locke and Malebranche in fact understood them.

Although ideas give rise to many problems of interpretation, but between them they define a space of philosophical problems. Ideas are that with which we think, or in Locke’s terms, whatever the mind may be employed about in thinking. Looked at that way, they seem to be inherent ly transient, fleeting, and unstable private presences. Ideas provide the way in which objective knowledge can be expressed. They are the essential components of understanding, and any intelligible proposition that is true must be capable of being understood. Plato’s theory of ‘forms’ is a launching celebration of the objective and timeless existence of ideas as concepts, and reified to the point where they make up the only real world, of separate and perfect models of which the empirical world is only a poor cousin. This doctrine, notably in the Timaeus, opened the way for the Neoplatonic notion of ideas as the thoughts of God. The concept gradually lost this other-worldly aspect, until after Descartes ideas become assimilated to whatever it is that lies in the mind of any thinking being.

Together with a general bias toward the sensory, so that what lies in the mind may be thought of as something like images, and a belief that thinking is well explained as the manipulation having no real existence but existing in a fancied imagination. It is not reason but ‘the imagination’ that is found to be responsible for our making the empirical inferences that we do. There are certain general ‘principles of the imagination’ according to which ideas naturally come ans goo in the mind under certain conditions. It is the task of the ‘science of human nature’ to discover such principles, but without itself going beyond experience. For example, an observed correlation between things of two kinds can be seen to produce in everyone a propensity to expect a thing to the second sort given an experience of a thing of the first sort. We get a feeling, or an ‘impression’, when the mind makes such a transition and that is what leads us to attribute necessarily to the reflation between things of the two kinds, there is no necessity in the relations between things that happen in the world, but, given our experience e and the way our minds naturally work, we cannot help thinking that there is.

A similar appeal to certain ‘principles of the imagination’ is what explains our belief in a world of enduring objects. Experience alone cannot produce that belief, everything we directly perceive is ‘momentary and fleeting’. And whatever our experience is like, no reasoning could assure us of the existence of something independent of our impressions which continues to exist when they cease. The series of our constantly changing sense impressions presents us with observable features which Hume calls ‘constancy ‘ and ‘coherence’, and these naturally operate on the mind in such a way as eventually to produce ‘the opinion of a continued and distinct existence’. psychological mechanisms which can ne discovered by ‘careful and exact experiments, and the observation of those particular effects, which result from [the mind’s] different circumstances and situations’.

We never directly perceive anything we can call ourselves: The most we can be aware of in ourselves are our constantly changing momentary perceptions, not the mind or self which has them. For Hume, there is nothing that really binds the different perceptions together, we are led into the ‘fiction’ that they form a unity only because of the way in which the thought of such series of perceptions works upon the mind. ‘The mind is a kind of theater, where several perceptions successively make their appearance, . . . there is properly no simplicity in it at one time, nor identity in different: Whatever natural propensity we may have to imagine that simplicity and identity. The comparison of the theater must not mislead us. They are the successive perceptions only, that constitute the mind.

Leibniz’s held, in opposition to Descartes, that adult humans can have experiences of which they are unaware: Experiences of which affect what they do, but which are not brought to self-consciousness. Yet there are creatures, such as animals and babies, which completely lack the ability to reflect of their experiences, and to become aware of them as experiences of theirs. The unity of a subject’s experience, which stems from his capacity to recognize all his experience as his, was dubbed by Kant ‘the transcendental unity of apperception ~ Leibniz’s term for inner awareness or self-consciousness. In contrast with ‘perception’ or outer awareness ~. However, this apprehension of unity is transcendental, than empirical, because it is presupposed in experience and cannot be derived from it. Kant used the need for this unity as the basis of his attempted refutation of scepticism about the external world. He argued that my experiences could only be united in one self-consciousness if at least some of them were experiences of a law-governed world of objects in space. Outer experience is thus a necessary condition of inner awareness.

Here we seem to have a clear case of ‘introspection’, derived from the Latin ‘intro’ (within) + ‘specere’ (to look), introspection is the attention the mind gives to itself or to its own operations and occurrences. I can know there is a fat hairy spider in my bath by looking there and seeing it. Bu t how do I know that I am seeing it rather than smelling it, or that my attitude to it is one of disgust than delight? One answer is: by a subsequent introspective act of ‘looking within’ and attending to the psychological state ~ my seeing the spider. Introspection, therefore, is a mental occurrence, which has as its object some other psychological state like perceiving, desiring, willing, feeling, etc. In being a distinct awareness-episode it is different from a more general ‘self-consciousness’ which characterize all or some of our mental history.

The awareness generated by an introspective act can have varying degrees of complexity. It might be a simple knowledge of (mental) things ~ such as a particular perception-episode, or it might be the more complex knowledge of truths about one’s own mind. In this latter full-blown judgement form, introspection is usually the self-ascription of psychological properties and, when linguistically expressed, results in statements like ‘I am watching the spider’ or ‘I am repulsed’.

In psychology this deliberate inward look becomes a scientific method when it is ‘directed towards answering questions of theoretical importance for the advancement of our systematic knowledge of the laws and conditions of mental processes’. In philosophy, introspection (sometimes also called ‘reflection’) remains simply ‘that notice which mind takes of its own operations and has been used to serve the important functions

Nonetheless, the concept of the given-referential immediacy as apprehended of the contents of sense experience is expressed in the first person, and present tense reports of appearances. Apprehension of the given is seen as immediate both in a causal sense, since it lacks the usual causal chain involved in perceiving real qualities of physical objects, and in an epistemic sense, since judgements expressing it are justified independently of all other beliefs and evidence. Some proponents of the idea of the given maintain that its apprehension is absolutely certain: Infallible, incorrigible and indubitable. It has been claimed also that a subject is omniscient with regard to the given ~ if a property appears, then the subject knows this.

Without some independent indication that some of the beliefs within a coherent system are true, coherence in itself is no indication of truth. Fairy stories can cohere, however, our criteria for justification must indicate to us the probable truth of our beliefs. Hence, within any system of beliefs there mus t be some privileged class with which others must cohere to be justified. In the case of empirical knowledge, such privileged beliefs must represent the point of contact between subject and world: They must originate in perception, that when challenged, however, we justify our ordinary perceptual beliefs about physical properties by appeal to beliefs about appearances. The latter seem more suitable as foundational, since there is no class of more certain perceptual beliefs to which we appeal for their justification.

The argument that foundations must be certain was offered by Lewis (1946). He held that no proposition can be probable unless some are certain. If the probability of all propositions or beliefs were relative to evidence expressed in others, and if these relations were linear, then any regress would apparently have to terminate in propositions or beliefs that are certain. But Lewis shows neither that such relations must be linear nor that redresses cannot terminate in beliefs that are merely probable or justified in themselves without being certain or infallible.

Arguments against the idea of the given originate with Kant, who argues that percepts without concepts do not yet constitute any form of knowing. Being non-epistemic, they presumably cannot serve as epistemic foundations. Once we recognize that we must apply concepts of properties to appearances and formulate beliefs utilizing those concepts before the appearances can play any epistemic role, it becomes more plausible that such beliefs are fallible. The argument was developed by Wilfrid Sellars (1963), that according to him, the idea of the given involves a confusion between sensing particulars (having sense impressions), which is non-epistemic, and having non-inferential knowledge of propositions referring to appearances. The former may be necessary for acquiring perceptual knowledge, but it is not itself a primitive kind of knowing. Its being non-epistemic renders it immune from error, but also unsuitable for epistemological foundations. The latter, non-referential perceptual knowledge, is fallible, requiring concepts acquired through trained responses to public physical objects.

Contemporary foundationalist’s deny the coherentist’s claim whole eschewing the claim that foundations, in the form of reports about appearances, are infallible. They seek alternatives to the given as foundations. Although arguments against infallibility are sound, other objections to the idea of foundations are not. That concepts of objective properties are learned prior to concepts of appearances, for example, implied neither that claims about appearances are less certain than claims about objective properties, nor that the latter are prior in chains of justification. That there can be no knowledge prior to the acquisition and consistent application of concepts allows for propositions whose truth requires only consistent application of concepts, and this may be so for some claims about appearances, least of mention, coherentists would add that such genuine beliefs stand in need of justification themselves and so cannot be foundations.

Coherentists will claim that a subject requires evidence that he applies concepts consistently, that he is able, for example, consistently to distinguish red from other colours that appear. Beliefs about red appearances could not then be justified independently of other beliefs expressing that evidence. To save that part of the doctrine of the given that holds beliefs about appearances to be self-justified, we require an account of how such justification is possible, how some beliefs about appearances can be justified without appeal to evidence. Some foundationalists simply assert such warrant as derived from experience, but, unlike appeals to certainty by proponents of the given.

Furthering towards the legitimate question: How do I know that I am seeing a spider? Was interpreted as a demand for the faculty or information-processing-mechanism whereby I come to acquire this knowledge. Peculiarities of first-person psychological awareness and reports were carried over as peculiarities of this mechanism. However, the question need not demand the search for a method of knowing but rather for an explanation of the special epistemic features of first-person psychological statements. In that, the problem of introspection (as a way of knowing) dissolves but the problem of explaining ‘introspective’ or first-person authority remains.

Traditionally, belief has been of epistemological interest in its propositional guise: ‘S’ believes that ‘p’, where ‘p’ is a proposition towards which an agent, ‘S’, exhibits an attitude of acceptance . No all belief is of this sort . If I trust what you say, I believe you. And someone may believe in Mrs. Collins, or in a free-market economy, or in God. It is sometimes supposed that all beliefs is ‘reducible’ to propositional belief, belief-that. Thus, my believing you might be thought as matter of my believing, perhaps, that what you say is true, and your belief in free markets or in God, a matter of your believing that free-market economies are desirable or that God exists.

It is doubtful, however, that non-propositional believing can, in every case, be reduced in this way. Debated on this point has tended to focus on an apparent distinction between ‘belief-that’ and ‘belief-in’, and the application of this distinction to belief in God: St. Thomas Aquinas (1225-64), accepted or advanced as true or real on the basis of less than convincing evidence in supposing that to believe in God is simply to believe that certain truths hold, such that God exists, that he is benevolent, etc. Others ague that belief-in is a distinctive attitude, one that includes essentially an element of trust. More commonly, belief-in has been taken to involve a combination of propositional belief together with some further attitude.

H.H. Price (1969) defends the claim that there are different sorts of belief-in, some, but not all, reducible to beliefs-that. If you believe in God, you believe that God exists, that God is good, etc. Bu t, according to Price, your belief involves, in addition, a certain complex pro-attitude toward its object. One might attempt to analyse this further attitude in terms of additional beliefs-that: ‘S’ believes in ‘χ’ exists (and perhaps holds further factual beliefs about ‘χ’) (2) ‘S’ believes that ‘χ; is good or valuable in some respect; and (3) ‘S’ believes that χ’s being good or valuable in this respect is itself is a good thing. An analysis of this sort, however, fails adequately to capture the further affective component of belief-in. Thus, according to Price, if you believe in God, your belief is merely that certain truths hold: You possess, in addition, an attitude of commitment and trust towards God.

Notoriously, belief-in outruns the evidence for the corresponding belief-that. Does this diminish its rationality? If belief-in presupposes belief-that, it might be thought that the evidential standards for the former must be, at least, as, high as standards for the latter. And any additional pro-attitude might be thought to require e a further layers of justification not required for cases of belief-that.

Some philosophers have argued that, at least for cases in which belief-in is synonymous with faith (or, faith-in), evidential thresholds for constituent propositional beliefs are diminished. You may reasonably have faith in God or Mrs. Collins, even though beliefs about their respective attributes, were you to harbour them would be evidentially standard.

Belief-in may be, in general, less susceptible to alteration in the face of unfavourable evidence than belief-that. A believer who encounters evidence against God’s existence may remain unshaken in his belief, in part because the evidence does not bear in his pro-attitude. So long as this is united with his belief that God exists, the belief may survive epistemic buffeting ~ and reasonably so ~ in a way that an ordinary propositional belief that would not.

What is at stake here is the appropriateness of distinct types of explanation. That ever since the times of Aristotle (384-322Bc) philosophers have emphasized the importance of explanatory knowledge. In simplest terms, we want to know not only what is the case but also why it is. This consideration suggests that we define ab explanation as an answer to a why-question. Such a definition would, however, be too broad, because some why-questions are request for consolation (Why did my son have to die?) Or moral justification (Why should woman not be paid the same as men for the same work?) It would also be too narrow because some explanations are responses to how-questions (How does radar work?) Or how-possibly-questions (How is it possible for cats always to land on four feet?)

In its most general sense , ‘to explain’ means to make clear, to make plain, or to provide understanding. Definitions of this sort used philosophically un-helped, for the terms used in the definitions are no less problematic than the term to be defined. Moreover, since a wide variety of things require explanation, and since many different types of explanation exist, a more complex explanation is required. The term ‘explanandum’ is used to refer to that which is to be explained: The term ‘explanans’ refers to that which does the explaining. The explanams and the explanandum taken together constitute the explanation.

One common type of explanation occurs when deliberate human actions are explained in terms of conscionable purposes. ‘Why did you go to the pharmacy yesterday? ‘Because I had a headache and needed to get some aspirin’. It is tacitly assumed that aspirin is an appropriate medication for headaches and that going to the pharmacy would be an efficient way of getting some. Such explanations are, of course, teleological, referring, as they do to goals. The explanans is not the realisation of a future goal ~ if the pharmacy happened to be closed for stocktaking the aspirin would not have been obtained there, but that would not invalidate the explanation. Some philosophers would say that the antecedent desire to achieve the end is what does the explaining: Others might say that the explaining is done by the nature of the goal and the fact that the action promoted the chances of realizing I t. in any case, it should not be automatically assumed that such explanations are causal. Philosophers differ considerably on whether these explanations are to be framed in terms of cause or reason

The distinction between reason and causes is motivate d in good part by a desire to separate the rational from the natural order. Many who have insisted on distinguishing reasons from causes have failed to distinguish two kinds of reason. Consider my reason for sending a letter by express mail. Asked why I did so, I might say I wanted to get it there in a day, or simply: to get it there in a day . Strictly, the reason is expressed by ‘to get it there in a day’. But what this expresses is my reason only because I am suitably motivated, in that I am in a reason state, wanting to get the letter there in a day. It is reason states ~ especially wants, beliefs and intentional ~ and not reasons strictly so called, that are candidates for causes. The latter are abstract contents of propositional altitudes, as the former are psychological elements that play motivational roles.

It has also seemed to those who deny that reasons are causes that the former justify, as well as explain the actions for which they are reasons, whereas the role of causes is at most to explain. Another claim is that the relation between reasons (and here reason states are often cited explicitly) and the action they explain is non-contingent: Whereas, the relation of causes to their effects is contingent. The ‘logical connection argument’ proceeds from this claim to the conclusion that reasons are mot causes.

All the same, the explanation as framed in terms of reason and or causes, and there are many differing analyses of such concepts as intention and agency. Expanding the domain beyond consciousness. Freud maintained, in addition, that much human behaviour can be explained in terms of unconscious wishes. These Freudian explanations should probably be construed as basically causal.

Problems arise when teleological explanations are offered in other context. The behaviour of non-human animals is often explained in terms of purpose, e.g., the mouse ran to escape from the cat. In such cases the existence of conscious purpose seems dubious. The situation is still more problematic when a super-empirical purpose is invoked ~, e.g., the explanation of living species in terms of God’s purpose, or the vitalistic explanation of biological phenomena in terms of an entelechy or vital principle. In recent years an ‘anthropic principle’ has received attention in cosmology. All such explanations have been condemned by many philosophers as anthropomorphic.

The preceding objection, for and all, that philosophers and scientists often maintain that functional explanations play an important and legitimate role in various sciences such as evolutionary biology, anthropology and sociology. For example, the case of the peppered moth in Liverpool, the change in colour and back again to the light phase provided adaption to a changing environment and fulfilled the function of reducing predation on the species. In the study of primitive societies anthropologists have maintained that various rituals, e.g., a rain dance, which may be inefficacious in bring about their manifest goals, e.g., producing rain. Actually fulfil the latent function of increasing social cohesion at a period of stress, e.g., theological and/or functional explanations in common sense ans science often take pains to argue that such explanations can be analysed entirely in terms of efficient causes, thereby escaping the change of anthropomorphism, yet not all philosophers agree.

Mainly to avoid the incursion of unwanted theology, metaphysics, or anthropomorphism into science, many philosophers and scientist ~ especially during the first half of the twentieth century ~ held that science provides only descriptions and predictions of natural phenomena, but not explanations. Beginning in the 1930s, however, a series of influential philosophers of science ~ including Karl Pooper (1935) Carl Hempel and Paul Oppenheim (1948) and Hempel (1965) ~ maintained that empirical science can explain natural phenomena without appealing to metaphysics and theology. It appears that this view is now accepted by a vast majority of philosophers of science, though there is sharp disagreement on the nature of scientific explanation.

The previous approach, developed by Hempel Popper and others became virtually a ‘received view’ in the 1960s and 1970s. According to this view, to give scientific explanation of an natural phenomenon is to show how this phenomenon can be subsumed under a law of nature. A particular rupture in a water pipe can be explained by citing the universal law that water expands when it freezes and the fact that the temperature of the water in the pipe dropped below the freezing point. General laws, as well as particular facts, can be explained by subsumption. The law of conservation of linear momentum can be explained by derivation from Newton’s second and third laws of motion. Each of these explanations is a deductive argument: The premisses constitute the explanans and the conclusion is the explanandum. The explanans contain one or more statements of universal laws and, in many cases, statements describing initial conditions. This pattern of explanation is known as the ‘deductive-nomological model’ any such argument shows that the explanandum had tp occur given the explanans.

Moreover, in contrast to the foregoing views ~ which stress such factors as logical relations, laws of nature and causality ~ a number of philosopher have argued that explanation, and not just scientific explanation, can be analysed entirely in pragmatic terms.

During the past half-century much philosophical attention has been focussed on explanation in science and in history. Considerable controversy has surrounded the question of whether historical explanation must be scientific, or whether history requires explanations of different types. Many diverse views have been articulated: the foregoing brief surveys does not exhaust the variety.

In everyday life we encounter may types of explanation, which appear not to raise philosophical difficulties, in addition to those already of mention. Prior to take-off a flight attendant explain how to use the safety equipment on the aeroplane. In a museum the guide explains the significance of a famous painting. A mathematics teacher explains a geometrical proof to be a bewildered student. A newspaper story explains how a prisoner escaped. Additional examples come easily to mind. The main point is to remember the great variety of context in which explanations are sought and given.

Another item of importance to epistemology is the widely held notion that non-demonstrative inference can be characterized as the inference to the best explanation. Given the variety of views on the nature of explanation, this popular slogan can hardly provide a useful philosophical analysis.

The inference to the best explanation is claimed by many to be a legitimate form of non-deductive reasoning, which provides an important alternative to both deduction and enumerative induction. Some would claim it is only through reasoning to the best explanation that one can justify beliefs about the external world, the past, theoretical entities in science, and even the future. Consider belief about the external world and assume that we know what we do about our subjective and fleeting sensations. It seems obvious that we cannot deduce any truths about the existence of physical objects from truths describing the character of our sensations. But neither can we observe a correlation between sensations and something other than sensations since by hypothesis all we eve have to rely on ultimately is knowledge of our sensations. Nonetheless, we may be able to posit physical objects as the best explanation for the character and order of our sensations. In the same way, various hypotheses about the past might best explain present memory: Theatrical postulates in physics might best explain phenomena in the macro-world, and it is possible that our access to the future is through past observations. But what exactly is the form of an inference to the best explanation?

When one presents such an inference in ordinary discourse it often seems to have as of:

1. ‘O’ is the case

2. If ‘E’ had been the case ‘O’ is what we would expect,

Therefore there is a high probability that

3. ‘E’ was the case.

This is the argument form that Peirce (1839-1914) called hypophysis or abduction. To consider a very simple example, we might upon coming across some footsteps on the beach, reason to the conclusion that a person walking along the beach recently by noting that if a person had walked along the beach one would expect to find just such footsteps.

But is abduction a legitimate form of reasoning? Obviously, if the conditional in (2) above is read as a material conditional such arguments would be hopelessly based. Since the proposition that ‘E’ materially implies ‘O’ is entailed by ‘O’, there would always be an infinite number of competing inferences to the best explanation and none of them would seem to lend support to its conclusion. The conditionals we employ in ordinary discourse, however, are seldom, if ever, material conditionals. Such that the vast majority of ‘if . ., . then . . . ‘ statements do not seem to be truth-functionally complex. Rather, they seem to assert a connection of some sort between the states of affairs referred to in the antecedent (after the ‘if’) and in the consequent (after the ‘then’). Perhaps the argument form has more plausibility if the conditional is read in this more natural way. But consider an alternative footsteps explanation:

1. There are footprints on the beach

2. If cows wearing boots had walked along the beach recently one would expect to find such footprints

Therefore. There is a high probability that

3. Cows wearing boots walked along the beach recently.

This inference has precisely the same form as the earlier inference to the conclusion that people walked along the beach recently and its premisses are just as true, but we would no doubt regard both the conclusion and the inference as simply silly. If we are to distinguish between legitimate and illegitimate reasoning to the best explanation it would seem that we need a more sophisticated model of the argument form. It would seem that in reasoning to an explanation we need criteria for choosing between alternative explanations. If reasoning to the best explanation is to constitute a genuine alternative to inductive reasoning. It is important that these criteria not be implicit premisses which will convert our argument into an inductive argument. Thus, for example, if the reason we conclude that people rather than cows walked along the beach is only that we are implicitly relying on the premiss that footprints of this sort are usually produced by people,. Then it is certainly tempting to suppose that our inference to the best explanation was really a disguised inductive inference of the form:

1. Most footprints are produced by people.

2. Here are footprints

Therefore in all probability,

3. These footprints were produced by people.

If we follow the suggestion made above, we might construe the form of reasoning to the best explanation, such that:

1. ‘O’ (a description of some phenomenon).

2. Of the set of available and competing explanations E1, E2 . . ., En capable of explaining ‘O’, E1 is the best according to the correct criteria for choosing among potential explanations.

Therefore in all probability,

3. E1.

Here too, is a crucial ambiguity in the concept of the best explanation. It might be true of an explanation E1 that it has the best chance of being correct without it being probable that E1 is correct. If I have two tickets in the lottery and one hundred other people each have one ticket, I am the person who has the best chance of winning, but it would be completely irrational to conclude on that basis that I am likely to win. It is much more likely that one of the other people will win than I will win. To conclude that a given explanation is actually likely to be correct on must hold that it is more likely that it is true than that the distinction of all other possible explanations is correct. And since on many models of explanation the number of potential explanations satisfying the formal requirements of adequate explanation is unlimited this will be normal feat.

Explanations are also sometimes taken to be more plausible the more explanatory ‘power’ they have. This power is usually defined in terms of the number of things or more likely, the number of kinds of things, the theory can explain. Thus, Newtonian mechanics was so attractive, the argument goes, partly because of the range of phenomena the theory could explain.

The familiarity of an explanation in terms of explanations is also sometimes cited as a reason for preferring that explanation to less familiar kinds of explanation. So if one provides a kind of evolutionary explanation for the disappearance of one organ in a creature, one should look more favourably on a similar sort of explanation for the disappearance of another organ.

Evaluating the claim that inference to the best explanation constitutes a legitimate and independent argument form. One must explore the question of whether it is a contingent fact that, at least, most phenomena have explanations and that explanations that satisfy a given criterions, simplicity, for example, are more likely to be correct. While it might be nice if the universe were structured in such a way that simple, powerful, familiar explanations were usually the correct explanation, it is difficult to avoid the conclusion that if this is true it would be an empirical fact about our universe discovered only a posteriori. If the reasoning to the explanation relies on such criteria, it seems that one cannot without circularity use reasoning to the best explanation to discover that the reliance on such criteria is safe. But if one has some independent way of discovering that simple, powerful, familiar explanations are more often correct, then why should we think that reasoning to the best explanation is an independent source of information about the world? Again, why should we not conclude that it would be more perspicuous to represent the reasoning this way:

1. Most phenomena have the simplest, most powerful, familiar explanations available

2. Here is an observed phenomena, and E1 is the simplest, most powerful, familiar explanation available.

Therefore, in all probability,

3. This is to be explained by E1.

But the above is simply an instance of familiar inductive reasoning.

There are various ways of classifying mental activities and states. One useful distinction is that between the propositional attitudes and everything else. A propositional attitude in one whose description takes a sentence as complement of the verb. Belief is a propositional attitude: One believes (truly or falsely as the case may be), that there are cookies in the jar. That there are cookies in the jar is the proposition expressed by the sentence following the verb. Knowing, judging, inferring, concluding and doubting are also propositional attitudes: One knows, judges, infers, concludes, or doubts that a certain proposition (the one expressed by the sentential complement) is true.

Though the propositions are not always explicit, hope, fear, expectation. Intention, and a great many others terms are also (usually) taken to describe propositional attitudes, one hopes that (is afraid that, etc.) there are cookies in the jar. Wanting a cookie is, or can be construed as, a propositional attitude: Wanting that one have (or eat or whatever) a cookie, intending to eat a cookie is intending that one will eat a cookie.

Propositional attitudes involve the possession and use of concepts and are, in this sense, representational. One must have some knowledge or understanding of what χ’s are in order to think, believe or hope that something is ‘χ’. In order to want a cookie, intend to eat one must, in some way, know or understand what a cookie is. One must have this concept. There is a sense in which one can want to eat a cookie without knowing what a cookie is ~ if, for example, one mistakenly thinks there are muffins in the jar and, as a result wants to eat what is in the jar (= cookies). But this sense is hardly relevant, for in this sense one can want to eat the cookies in the jar without wanting to eat any cookies. For this reason(and this sense) the propositional attitudes are cognitive: They require or presuppose a level of understanding and knowledge, this kind of understanding and knowledge required to possess the concepts involved in occupying the propositional state.

Thought there is sometimes disagreement about their proper analysis, non-propositional mental states, yet do not, at least on the surface, take propositions as their object. Being in pain, being thirsty, smelling the flowers and feeling sad are introspectively prominent mental states that do not, like the propositional attitudes, require the application or use of concepts. One doesn’t have to understand what pain or thirst is to experience pain or thirst. Assuming that pain and thirst are conscious phenomena, one must, of course, be conscious or aware of the pain or thirst to experience them, but awareness of must be carefully distinguished from awareness that. One can be aware of ‘χ’ ~ thirst or a toothache ~ without being aware that, that, e.g., thirst or a toothache, is that like belief that and knowledge that, is a propositional attitude, awareness of is not.

As the examples, pain, thirst, tickles, itches, hunger are meant to suggest, the non-propositional states have a felt or experienced [‘phenomenal’] quality to them that is absent in the case of the propositional attitudes. Aside from who it is we believe to be playing the tuba, believing that John is playing the tuba is much the same as believing that Joan is playing the tuba. These are different propositional states, different beliefs, yet, they are distinguished entirely in terms of their propositional content ~ in terms of what they are beliefs about. Contrast this with the difference between hearing John play the tuba and seeing him play the tuba. Hearing John play the tuba and seeing John play the tuba differ, not just (as do beliefs) in what they are of or about (for these experiences are, in fact, of the same thing: John playing the tuba), but in their qualitative character, the one involves a visual, the other an auditory, experience. The difference between seeing John play the tuba and hearing John play the tuba, then, is a sensory not a cognitive difference.

Some mental states are a combination of sensory and cognitive elements. Fear and terror, sadness and anger, joy and depression, are ordinarily thought of in this way sensations are: Not in terms of what propositions (if any) they represent, but (like visual and auditory experience) in their intrinsic character, in how they feel to the person experiencing them. But when we describe a person as being afraid that, sad that, upset that (as opposed to merely thinking or knowing that) so-and-so happened, we typically mean to be describing the kind of sensory (feeling or emotional) quality accompanying the cognitive state. Being afraid that the dog is going to bite me is both to think (that he might bite me) ~ a cognitive state ~ and feel fear or apprehension (sensory) at the prospect.

The perceptual verbs exhibit this kind of mixture, this duality between the sensory and the cognitive. Verbs like ‘to hear’, ‘to say’, and ‘to feel’ are [often] used to describe propositional (cognitive) states, but they describe these states in terms of the way (sensory) one comes to be in them. Seeing that there are two cookies left by seeing. Feeling that there are two cookies left is coming to know this in a different way, by having tactile experiences (sensations).

On this model of the sensory-cognitive distinction (at least it is realized in perceptual phenomena). Sensations are a pre-conceptual, a pre-cognitive, vehicle of sensory information. The terms ‘sensation’ and ‘sense-data’ (or simply ‘experience’) were (and, in some circles, still are) used to describe this early phase of perceptual processing. It is currently more fashionable to speak of this sensory component in perception as the percept, the sensory information store, is generally the same: An acknowledgement of a stage in perceptual processing in which the incoming information is embodied in ‘raw’ sensory (pre-categorical, pre-0recognitional) form. This early phase of the process is comparatively modular ~ relatively immune to, and insulated from, cognitive influence. The emergence of a propositional [cognitive] state ~ seeing that an object is red ~ depends, then, on the earlier occurrence of a conscious, but nonetheless, non-propositional condition, seeing (under the right condition, of course) the red object. The sensory phase of this process constitutes the delivery of information (about the red object) in a particular form (visual): Cognitive mechanisms are then responsible for extracting and using this information ~ for generating the belief (knowledge) that the object is red. (The belief of blindness suggests that this information can be delivered, perhaps in degraded form, at a non-conscious level.)

To speak of sensations of red objects, tubes and so forth, is to say that these sensations carry information about an object’s colour, its shape, orientation, and position and (in the case of audition) information about acoustic qualities such as pitch, timbre, volume. It is not to say that the sensations share the properties of the objects they are sensations of or that they have the properties they carry information about. Auditory sensations are not loud and visual sensations are not coloured. Sensations are bearers of nonconceptualized information, and the bearer of the information that something is red need not itself be red. It need not even be the sort of thing that could be red: It might be a certain pattern of neuronal events in the brain. Nonetheless, the sensation, though not itself red, will (being the normal bearer of the information) typically produce in the subject who undergoes the experience a belief, or tendency to believe, that something red is being experienced. Hence the existence of hallucinations.

Just as there are theories of the mind, that would deny the existence of any state of mind whose essence was purely qualitative (i.e., did not consists of the state’s extrinsic, causal, properties) there are theories of perception and knowledge ~ cognitive theories ~ that deny a sensory component to ordinary sense perception. The sensor y dimension (the look, feel, smell, taste of things) is (if it isn’ t altogether r denied) identified with some cognitive condition (knowledge or belief) of the experienced. All seeing (not to mention hearing, smelling and feeling) becomes a form of believing or knowing. As a result, organisms that cannot know cannot have experiences. Often, to avoid these striking counterintuitive results, implicit or otherwise unobtrusive (and, typically, undetectable) forms of believing or, knowing.

Aside, though, from introspective evidence (closing and opening one’s eyes, if it changes beliefs at all, doesn’t just change beliefs, it eliminates and restores a distinctive kind of conscionable experience), there is a variety of empirical evidence for the existence of a stage in perceptual processing that is conscious without being cognitive (in any recognizable sense). For example, experiments with brief visual displays reveal that when subjects are exposed for very brief (50 msec.) Intervals to information-rich stimuli, there is persistence (at the conscious level) of what is called an image or visual icon that embodies more information about the stimulus than the subject can cognitively process or report on. Subjects cab exploit the information in this persisting icon by reporting on any part of the absent array of numbers (the y can, for instance, reports of the top three numbers, the middle three or the bottom three). They cannot, however, identify all nine numbers. The y report seeing all nine, and the y can identify any one of the nine, but they cannot identify all nine. Knowledge and brief, recognition and identification ~ these cognitive states, though present for any two or three numbers in the array, are absent for all nine numbers in the array. Yet, the image carries information about all nine numbers (how else accounts for subject’s ability to identify any number in the absent array?) Obviously, then, information is there, in the experience itself, whether or not it is, or even can be. As psychologists conclude, there is a limit on the information processing capacities of the latter (cognitive) mechanisms that is not shared by the sensory stages themselves.

Perceptual knowledge is knowledge acquired by or through the senses. This includes most of what we know. Some would say it includes everything we know. We cross intersections when we see the light turn green, head for the kitchen when we smell the roast burning, squeeze the fruit to determine its ripeness, and climb out of bed when we hear the alarm, ring. In each case we come to know something ~ that the light has turned green, that the roast is burning, that the melon is overripe, and that it is time to get up ~ that the light has turned green ~ by use of the eyes. Feeling that the melon is overripe in coming to know a fact ~ that the melon is overripe ~ by one’s sense of touch. In each case the resulting knowledge is somehow based on, derived from or grounded in the sort of experience that characterizes the sense modality in question.

Seeing a rotten kumquat is not at all like the experience of smelling, tasting or feeling a rotten kumquat. Yet all these experiences can result in the same knowledge ~ Knowledge that the kumquat is rotten. Although the experiences are much different, they must, if they are to yield knowledge, embody information about the kumquat: The information that it is rotten. Seeing that the fruit is rotten differs from smelling that it is rotten, not in what is known, but how it is known. In each case, the information has the same source ~ the rotten kumquat ~, but it is, so top speak, delivered via different channels and coded and re-coded in different experiential neuronal excitations as stimulated sense attractions.

It is important to avoid confusing perceptual knowledge of facts, e.g., that the kumquat is rotten, with the perception of objects, e.g., rotten kumquats. It is one thing ro see (taste, smell, feel) a rotten kumquat, and quite another to know (by seeing or tasting) that it is a rotten kumquat. Some people, after all, don not know what kumquats look like. They see a kumquat but do not realize (do mot see that) it is a kumquat. Again, some people do not know what a kumquat smell like. They smell a rotten kumquat and ~ thinking, perhaps, that this is a way this strange fruit is supposed to smell ~ do no t realize from the smell, i.e., do not smell that it is a rotted kumquat. In such cases people see and smell rotten kumquats ~ and in this sense perceive rotten kumquat ~ and never know that they are kumquats ~ let alone rotten kumquats. They cannot, not at least by seeing and smelling, and not until they have learned something about (rotten) kumquats. Since the topic as such is incorporated in the perceptual knowledge ~ knowing, by sensory means, that something if ‘F’ ~, we will be primary concerned with the question of what more, beyond the perception of F’s, is needed to see that (and thereby know that) they are ‘F’. The question is, however, not how we see kumquats (for even the ignorant can do this) but, how we know (if, that in itself, that we do) that, that is what we see.

Much of our perceptual knowledge is indirect, dependent or derived. By this is that it is meant that the facts we describe ourselves as learning, as coming to know, by perceptual means are pieces of knowledge that depend on our coming to know something else, some other fat, in a more direct way. We see, by the gauge, that we need gas, see, by the newspapers, that our team has lost again, or see, by her expression that is nervous. This derived or dependent sort of obtainable knowledge is particularly prevalent in the case of vision but it occurs, to a lesser degree, in every sense modality. We install bells and other noise-makers so that we can, for example, hear (by the bells) that someone is at the door and (by the alarm) that its time to get away. When we obtain knowledge in this way. It is clear that unless one sees ~ hence, comes to know. Something about the gauge (that it reads ‘empty’), the newspaper (which is says) and the person’s expression, one would not see (hence, know) what one is described as coming to know by perceptual means. If one cannot hear that the bell is ringing, one cannot ~ not at least in this way ~ hear that one’s visitors have arrived. In such cases one sees (hears, smells, etc.) that ‘a’ is ‘F’, coming to know thereby that ‘a’

is ‘F’, by seeing (hearing, etc.) that some other condition, b’s being ‘G’, obtains. When this occurs, the knowledge (that ‘a’ is ‘F’) is derived, or dependent on, the more basic perceptual knowledge that ‘b’ is ‘G’.

Though perceptual knowledge about objects is often, in this way, dependent on knowledge of fats about different objects, the derived knowledge is sometimes about the same object. That is, we see that ‘a’ is ‘F’ by seeing, not that some other object is ‘G’, but that ‘a’ itself is ‘G’. We see, by her expression, that she is nervous. She tells that the fabric is silk (not polyester) by the characteristic ‘greasy’ feel of the fabric itself (not, as I do, by what is printed on the label). We tell whether it is an oak tree, a Porsche, a geranium, an igneous rock or a misprint by its shape, colour, texture, size, behaviour and distinctive markings. Perceptual knowledge of this sort is also deprived ~ derived from the more basic facts (about ‘a’) we use to make the identification. In this case the perceptual knowledge is still indirect because, although the same object is involved, the facts we come to know about it are different than the facts that enable us to know it.

Derived knowledge is sometimes described as inferential, but this is misleading, at the conscious level there is no passage of the mind from premise to conclusion, no reasoning, no problem-solving. The observer, the one who sees that ‘a’ is ‘F’ by seeing that ‘b’ (or ‘a’ itself) is ‘G’, need not be (and typically is not) aware of any process of inference, any passage of the mind from one belief to another. The resulting knowledge, though logically derivative, is psychologically immediate. I could see that she was getting angry: so, I moved my hand. I did not ~ at least not at any conscious level ~ infer (from her expression and behaviour) that she was getting angry. I could (or, so it seemed to me) see that she was getting angry. It is this psychological immediacy that makes indirect perceptual knowledge a species of perceptual knowledge.

The psychological immediacy that characterises so much of our perceptual knowledge ~ even (sometimes) the most indirect and derived forms of it ~ does not mean that learning is not required to know in this way. One is not born with (may, in fact, never develop) the ability to recognize daffodils, muskrats and angry companions. It is only after a long experience that one is able visually to identify such things. Beginners may do something corresponding to inference: They recognize relevant features of trees, birds, and flowers, factures they already know how to perceptually identify, and then infer (conclude), on the basis of what they see, and under the guidance of more expert observers, that its an oak a finch or a geranium. But the experts (and we are all experts on many aspects of our familiar surroundings) do not typically fo through such a process. The expert just sees that its an oak, a finch or a geranium. The perceptual knowledge of the expert is still dependent, of course, since even an expert cannot see what kind of flower it is if she cannot first see its colour and shape, but it is to say, that the expert has developed identificatory skills that no longer require the sort of conscious inferential processes that characterize a beginner’s efforts.

Coming to know that ‘a’ is ‘F’ by seeing that ‘b’ is ‘G’ obviously requires some background assumption on the part of the observer, an assumption to the effect that ‘a’ is ‘F’ (or perhaps only probable ‘F’) when ‘b’ is ‘G’. If one does not assume (as taken to be granted) that the gauge is properly connected, and does not, thereby assume that it would not register ‘empty’,unless the tank was nearly empty, then even if one could see that it registered ‘empty’, one would not learn ( hence, would not see) that one needed gas. At least, one would not see it by consulting the gauge. Likewise, in trying to identify birds, its no use being able to see their markings if one doesn’t know something about which birds have which marks ~ sometimes of the form: A bird with these markings is (probably) a finch.

It would seem, moreover, that these background assumptions, if they are to yield knowledge that ‘a’ is ‘F’, as they must if the observer is to see (by b’s being ‘G’) that ‘a’ is ‘F’, must themselves qualify as knowledge. For if this background fact is not known, if it is not known whether ‘a’ is ‘F’ when ‘b’ is ‘G’, then the knowledge of b’s being ‘G’, taken by itself, powerless to generate the knowledge that ‘a; is ‘F’. If the conclusion is to be known to be true, both the premises used to reach that conclusion must be known to be true. Or so it would seem.

Externalists, however, argue that the indirect knowledge that ‘a’ is ‘F’, though it may depend on the knowledge that ‘b’ is ‘G’, does not require knowledge of the connecting fact, the fact that ‘a’ is ‘F’ when ‘b’ is ‘G’. Simple belief (or, perhaps, justified belief, there are stronger and weaker versions of externalism) in the connecting fact is sufficient to confer a knowledge of the fact is sufficient to confer a knowledge e of the connected fact. Even if, strictly speaking, I don’t know she is nervous whenever she fidgets like that, I can nonetheless, see and hence know, that she is nervous by the way she fidgets, if I (correctly) assume that his behaviour r is a reliable expression of nervousness. One need not know the gauge is working well to make observations (acquire observational knowledge) with it. All that is required, besides the observer believing that the gauge is reliable, is that the gauge, in fact, be reliable, i.e., that the observer’s background beliefs be true. Critics of externalisms have been quick to point out that this theory has the unpalatable consequence that knowledge can be made possible by ~ and, in this sense, be made to rest on ~ lucky hunches (that turn out true) and unsupported (even irrational) beliefs. Surely, internalist argue, if one is going t o know that ‘a’ is ‘F’ on the basis of b’s being ‘G’, one should have (as a bare minimum) some justification for thinking that ‘a’ is ‘F’, or is probably ‘F’, when ‘b’ is ‘G’.

Whatever view one takes about these matters (with the possible exception of extreme externalism) indirect perception obviously requires some understanding (knowledge? Justification? Belief?) of the general relationship between the fact one comes to know (that ‘a’ is ‘F’) and the facts (that ‘b’ is ‘G’) that enable one to know it. And it is this requirement on background knowledge or understanding that leads to questions to questions about the possibility of indirect perceptual knowledge. Is it really knowledge? The first question is inspired by sceptical doubts about whether we can ever know the connecting facts in question. How is it possible to learn, to acquire knowledge of, the connecting facts knowledge of which is necessary to see,. By b’s being ‘G’, and that ‘a’ is ‘F’? These connecting facts do not appear to be perceptually knowable. Quite the contrary, they appear to b e general truths knowable (if knowable at all) by inductive inference e from past observations. And if one is sceptical about obtaining knowledge in this indirect, inductive way one is, perforced, sceptical about the existence of the kind of indirect knowledge, including indirect perceptual knowledge of the set described, in that depends on it.

Even if one puts aside such sceptical questions, how ever, there remains a legitimate concern about the perceptual character of this kind knowledge. If one sees that ‘a’ is ‘F’ by seeing that ‘b’ is ‘G’, is really seeing that ‘a’ is ‘F’? Isn’t perception merely a part ~ and, from an epistemological standpoint, the less significant part ~ of the process whereby one comes to know that ‘a’ is ‘F’. One must, it is true, sere that ‘b’ is ‘G’, but this is only one of the premises needed to reach the conclusion (knowledge) that ‘a’ is ‘F’. There is also the background knowledge that is essential to the process. If we think of a theory as any factual proposition, or set of factual propositions, that cannot itself be known in some direct observational way, we can express this worry by saying that indirect perception is always theory-loaded: Seeing (indirectly)that ‘a’ is ‘F’ is only possible if the observer already has knowledge of (justification for, belief in) some theory, the theory ‘connecting’ the fast one cannot come to know (that ‘a’ is ‘F’) with the fact (that ‘b’ is ‘G’) that enables one to know it.

This, of course, reverses the standard foundationalist picture of human knowledge. Instead of theoretical knowledge depending on, and being derived from, perception, perception (of the indirect sort) presupposes a prior knowledge.

Foundationalists are quick to point out that this apparent reversal in the structure of human knowledge is only apparent. Our indirect perception of facts depends on theory, yes, but this merely shows that indirect perceptual knowledge is not part of the foundation. To reach the kind of perceptual knowledge that lies at the foundation, we need to look at a form of perception that is purified of all theoretical elements. This then, will be perceptual knowledge pure and direct. No background knowledge or assumptions about connecting regularities are needed in direct perception because the known facts are presented directly and immediately and not (as, in indirect perception) on the basis of some other facts. In direct perception all the justification (needed for knowledge) is right there in the experience itself.

What, then, about the possibility of perceptual knowledge pure and direct, the possibility of coming to know, on the basis of sensory experience, that ‘a’ is ‘F’ where this does not require assumptions or knowledge that has a source outside the experience itself? Where is this epistemological ‘pure gold’ to be found?

There are, basically, two views about the nature of direct perceptual knowledge (coherentists would deny that any of our knowledge is basic in this sense). These views (following traditional nomenclature) can be called ‘direct realism’ and ‘representationalism’ or ‘representative realism’. A representationalist restricts direct perceptual knowledge to objects of a very special sort: Ideas, impressions, or sensations, sometimes called sense-data ~ entities in the mind of the observer. One directly perceives a fact, e.g., that ‘b’ is ‘G’ , only when ‘b’ is a mental entity of some sort ~ a subjective appearance or sense-data ~ and ‘G’ is a property of this datum. Knowledge of these sensory states is supposed to be certain and infallible. These sensory facts are, so o speak, right up against the mind’s eye. One cannot be mistaken about these facts for these facts are, in reality, facts about the way things appear to be, and one cannot be mistaken about the way things appear to be. Normal perception of external conditions, then, turns out to be (always) a type of indirect perception. One ‘sees’ that there is a tomato in front of one by seeing that the appearance (of the tomato) have a certain quality (reddish and bulgy) and inferring as this is topically said to be automatic and unconscious, on the basis of certain background assumptions, e.g., that there typically is a tomato in front of one when one has experiences of this sort, that there is a tomato in front of one. All knowledge of objective reality, then, even what commonsense regards as the most direct perceptual knowledge, is based on an even more direct knowledge of the appearances.

Although ideas give rise to many problems of interpretation, but between them they define a space of philosophical problems. Ideas are that with which we think, or in Locke’s terms, whatever the mind may be employed about in thinking. Looked at that way, they seem to be inherently transient, fleeting, and unstable private presences. Ideas provide the way in which objective knowledge can be expressed. They are the essential components of understanding, and any intelligible proposition that is true must be capable of being understood. Plato’s theory of ‘forms’ is a launching celebration of the objective and timeless existence of ideas as concepts, and reified to the point where they make up the only real world, of separate and perfect models of which the empirical world is only a poor cousin. This doctrine, notably in the ‘Timaeus’, opened the way for the Neoplatonic notion of ideas as the thoughts of God. The concept gradually lost this other-worldly aspect, until after Descartes ideas become assimilated to whatever it is that lies in the mind of any thinking being.

Together with a general bias toward the sensory, so that what lies in the mind may be thought of as something like images, and a belief that thinking is well explained as the manipulation having no real existence but existing in a fancied imagination. It is not reason but ‘the imagination’ that is found to be responsible for our making the empirical inferences that we do. There are certain general ‘principles of the imagination’ according to which ideas naturally come and go in the mind under certain conditions. It is the task of the ‘science of human nature’ to discover such principles, but without itself going beyond experience. For example, an observed correlation between things of two kinds can be seen to produce in everyone a propensity to expect a thing to the second sort given an experience of a thing of the first sort. We get a feeling, or an ‘impression’, when the mind makes such a transition and that is what leads us to attribute necessarily to the reflation between things of the two kinds, there is no necessity in the relations between things that happen in the world, but, given our experience and the way our minds naturally work, we cannot help thinking that there is.

A similar appeal to certain ‘principles of the imagination’ is what explains our belief in a world of enduring objects. Experience alone cannot produce that belief, everything we directly perceive is ‘momentary and fleeting’. And whatever our experience is like, no reasoning could assure us of the existence of something as autonomous of our impressions which continues to exist when they cease. The series of constantly changing sense impressions presents us with observable features which Hume calls ‘constancy ‘ and ‘coherence’, and these naturally operate on the mind in such a way as eventually to produce ‘the opinion of a continued and distinct existence’. The explanation is complicated, but it is meant to appeal only to psychological mechanisms which can be discovered by ‘careful and exact experiments, and the observation of those particular effects, which result from [the mind’s] different circumstances and situations’.

We believe not only in bodies, but also in persons, or selves, which continue to exist through time, and this belief too can be explained only by the operation of certain ‘principles of the imagination’. We never directly perceive anything we can call ourselves: The most we can be aware of in ourselves are our constantly changing momentary perceptions, not the mind or self which has them. For Hume, there is nothing that really binds the different perceptions together, we are led into the ‘fiction’ that they form a unity only because of the way in which the thought of such series of perceptions works upon the mind. ‘The mind is a kind of theatre, where several perceptions successively make their appearance, . . . there is properly no simplicity in it at one time, nor identity in different: Whatever natural propensity we may have to imagine that simplicity and identity. The comparison of the theatre must not mislead us. They are the successive perceptions only, that constitutes the mind.

Leibniz’s held, in opposition to Descartes, that adult humans can have experiences of which they are unaware: Experiences of which effect what they do, but which are not brought to self-consciousness. Yet there are creatures, such as animals and babies, which completely lack the ability to reflect of their experiences, and to become aware of them as experiences of theirs. The unity of a subject’s experience, which stems from his capacity to recognize all his experience as his, was dubbed by Kant ‘the transcendental unity of apperception - Leibniz’s term for inner awareness or self-consciousness. In contrast with ‘perception’ or outer awareness -. However, this apprehension of unity is transcendental, than empirical, because it is presupposed in experience and cannot be derived from it. Kant used the need for this unity as the basis of his attempted refutation of scepticism about the external world. He argued that my experiences could only be united in one-self-consciousness, if, at least some of them were experiences of a law-governed world of objects in space. Outer experience is thus a necessary condition of inner awareness.

Here we seem to have a clear case of ‘introspection’, derived from the Latin ‘intro’ (within) + ‘specere’ (to look), introspection is the attention the mind gives to itself or to its own operations and occurrences. I can know there is a fat hairy spider in my bath by looking there and seeing it. But how do I know that I am seeing it rather than smelling it, or that my attitude to it is one of disgust than delight? One answer is: By a subsequent introspective act of ‘looking within’ and attending to the psychological state, - my seeing the spider. Introspection, therefore, is a mental occurrence, which has, as its object, some other psychological state like perceiving, desiring, willing, feeling, etc. In being a distinct awareness-episode it is different from more general ‘self-consciousness’ which characterizes all or some of our mental history.

The awareness generated by an introspective act can have varying degrees of complexity. It might be a simple knowledge of (mental) things’ - such as a particular perception-episode, or it might be the more complex knowledge of truths about one’s own mind. In this latter full-blown judgement form, introspection is usually the self-ascription of psychological properties and, when linguistically expressed, results in statements like ‘I am watching the spider’ or ‘I am repulsed’.

In psychology this deliberate inward look becomes a scientific method when it is ‘directed toward answering questions of theoretical importance for the advancement of our systematic knowledge of the laws and conditions of mental processes’. In philosophy, introspection (sometimes also called ‘reflection’) remains simply ‘that notice which mind takes of its own operations and has been used to serve the following important functions:

(1) Methodological: Thought experiments are a powerful tool in philosophical investigation. The Ontological Argument, for example, asks us to try to think of the most perfect being as lacking existence and Berkeley’s Master Argument challenges us to conceive of an unseen tree, conceptual results are then drawn from our failure or success. From such experiments to work, we must not only have (or fail to have) the relevant conceptions but also know that we have (or fail to have) them - presumably by introspection.

(2) Metaphysical: A metaphysical of mind needs to take cognizance of introspection. One can argue for ‘ghostly’ mental entities for ‘qualia’, for ‘sense-data’ by claiming introspective awareness of them. First-person psychological reports can have special consequences for the nature of persons and personal identity: Hume, for example, was content to reject the notion of a soul-substance because he failed to find such a thing by ‘looking within’. Moreover, some philosophers argue for the existence of additional perspectival facts - the fact of ‘what it is like’ to be the person I am or to have an experience of such-and-such-a-kind. Introspection as our access to such facts becomes important when we construct a complete metaphysics of the world.

(3) Epistemological: Surprisingly, the most important use made of introspection has been in an accounting for our knowledge of the outside world. According to a foundationalist theory of justification an empirical belief is either basic and ‘self-justifying’ or justified in relation to basic beliefs. Basic beliefs therefore, constitute the rock-bottom of all justification and knowledge. Now introspective awareness is said to have a unique epistemological status in it, we are said to achieve the best possibly epistemological position and consequently, introspective beliefs and thereby constitute the foundation of all justification.

Coherence is a major player in the theatre of knowledge. There are coherence theories of belief, truth and justification where these combine in various ways to yield theories of knowledge, coherence theories of belief are concerned with the content of beliefs. Consider a belief you now have, the belief that you are reading a page in a book. So what makes that belief the belief that it is? What makes it the belief that you are reading a page in a book than the belief that you have something other of a preoccupation? The same stimuli may produce various beliefs and various beliefs may produce the same action. The role that gives the belief the content it has is the role it plays within a network of relations to other beliefs, the role in inference and implication, for example, I infer different things from believing that I am reading a page in a book than from any other belief, just as I infer that belief from different things than I refer other beliefs from.

The input of perception and the output of an action supplement the central role of the systematic relations the belief has to other beliefs, except that the systematic relations given to the belief specified of the content it has. They are the fundamental source of the content of beliefs. That is how coherence comes to be. A belief that the content that it does because of the away in which it coheres within the system of beliefs, however, weak coherence theories affirm that coherence is one determinant of the content of belief as strong coherence theories on the content of belief affirm that coherence is the sole determinant of the content of belief.

Nonetheless, the concept of the given-referential immediacy as apprehended of the contents of sense experience is expressed in the first person, and present tense reports of appearances. Apprehension of the given is seen as immediate both in a causal sense, since it lacks the usual causal chain involved in perceiving real qualities of physical objects, and in an epistemic sense, since judgements expressing it are justified independently of all other beliefs and evidence. Some proponents of the idea of the ‘given’ maintain that its apprehension is absolutely certain: Infallible, incorrigible and indubitable. It has been claimed also that a subject is omniscient with regard to the given - if a property appears, then the subject knows this.

Without some independent indication that some of the beliefs within a coherent system are true, coherence in itself is no indication of truth. Fairy stories can cohere, however, our criteria for justification must indicate to us the probable truth of our beliefs. Hence, within any system of beliefs there must be some privileged class with which others must cohere to be justified. In the case of empirical knowledge, such privileged beliefs must represent the point of contact between subject and world: They must originate within our descendable inherentability perceptions of the world, that when challenged, however, we justify our ordinary perceptual beliefs about physical properties by appeal to beliefs about appearances. The latter seem more suitable as foundational, since there is no class of more certain perceptual beliefs to which we appeal for their justification.

The argument that foundations must be certain was offered by Lewis (1946). He held that no proposition can be probable unless some are certain. If the probability of all propositions or beliefs were relative to evidence expressed in others, and if these relations were linear, then any regress would apparently have to terminate in propositions or beliefs that are certain. But Lewis shows neither that such relations must be linear nor that redresses cannot terminate in beliefs that are merely probable or justified in themselves without being certain or infallible.

Arguments against the idea of the given originate with Kant (1724-1804), who argues that percepts without concepts do not yet constitute any form of knowing. Being non-epistemic, they presumably cannot serve as epistemic foundations. Once we recognize that we must apply concepts of properties to appearances and formulate beliefs utilizing those concepts before the appearances can play any epistemic role, it becomes more plausible that such beliefs are fallible. The argument was developed by Wilfrid Sellars (1963), which according to him, the idea of the given involves a confusion between sensing particulars (having sense impressions), which is non-epistemic, and having non-inferential knowledge of propositions referring to appearances. The former may be necessary for acquiring perceptual knowledge, but it is not itself a primitive kind of knowing. Its being non-epistemic renders it immune from error, but also unsuitable for epistemological foundations. The latter, non-referential perceptual knowledge, are fallible, requiring concepts acquired through trained responses to public physical objects.

Contemporary foundationalist’s deny the coherentist’s claim whole eschewing the claim that foundations, in the form of reports about appearances, are infallible. They seek alternatives to the given as foundations. Although arguments against infallibility are sound, other objections to the idea of foundations are not. That concepts of objective properties are learned prior to concepts of appearances, for example, implied neither that claims about appearances are less certain than claims about objective properties, nor that the latter are prior in chains of justification. That there can be no knowledge prior to the acquisition and consistent application of concepts allows for propositions whose truth requires only consistent applications of concepts, and this may be so for some claims about appearances, least of mention, coherentists would add that such genuine belief’s stands in need of justification themselves and so cannot be foundations.

Coherentists will claim that a subject requires evidence that he applies concepts consistently that he is able, for example, consistently to distinguish red from other colours that appear. Beliefs about red appearances could not then be justified independently of other beliefs expressing that evidence. To say that part of the doctrine of the given that holds beliefs about appearances to be self-justified, we require an account of how such justification is possible, how some beliefs about appearances can be justified without appeal to evidence. Some foundationalists simply assert such warrant as derived from experience, but, unlike appeals to certainty by proponents of the given.

It is, nonetheless, an explanation of this capacity that enables its developments as an epistemological corollary to metaphysical dualism. The world of ‘matter’ is known through external/outer sense-perception. So cognitive access to ‘mind’ must be based on a parallel process of introspection which ‘thought . . . not ‘sense’, as having nothing to do with external objects: Yet [put] is very like it, and might properly enough be called ‘internal sense’. However, having mind as object, is not sufficient to make a way of knowing ‘inner’ in the relevant sense be because mental facts can be grasped through sources other than introspection. To point, is rather that ‘inner perception’, provides a kind of access to the mental not obtained otherwise - it is a ‘look within from within’. Stripped of metaphor this indicates the following epistemological features:

1. Only I can introspect my mind.

2. I can introspect only my mind.

3. Introspective awareness is superior to any other knowledge of contingent facts that I or others might have.

The tenets of (1) and (2) are grounded in the Cartesian of ‘privacy’ of the mental. Normally, a single object can be perceptually or inferentially grasped by many subjects, just as the same subject can perceive and infer different things. The epistemic peculiarity of introspection is that, is, is exclusive - it gives knowledge only of the mental history of the subject introspecting.

The tenet (2) of the traditional theory is grounded in the Cartesian idea of ‘privileged access’. The epistemic superiority of introspection lies in its being and infallible source of knowledge. First-person psychological statements which are its typical results cannot be mistaken. This claim is sometimes supported by an ‘imaginability test’, e.g., the impossibility of imaging that I believe that I am in pain, while at the same time imaging evidence that I am not in pain. An apparent counter-example to this infallibility claim would be the introspective judgement ‘I am perceiving a dead friend’ when I am really hallucinating. This is taken to by reformulating such introspective reports as ‘I seem to be perceiving a dead friend’. The importance of such privileged access is that introspection becomes a way of knowing immune from the pitfalls of other sources of cognition. The basic asymmetry between first and third person psychological statements by introspective and non-introspective methods, but even dualists can account for introspective awareness in different ways:

(1) Non-perceptual models - Self-scrutiny need not be perceptual. My awareness of an object ‘O’ changes the status of ‘O’. It now acquires the property of ‘being an object of awareness’. On the basis of this or the fact that I am aware of ‘O’, such an ‘inferential model’ of awareness is suggested by the Bhatta Mimamsa school of Indian Epistemology. This view of introspection does not construe it as a direct awareness of mental operations but, interestingly, we will have occasion to refer to theories where the emphasis on directness itself leads to a non-perceptual, or at least, a non-observational account of introspection.

(2) Reflexive models - Epistemic access to our minds need not involve a separate attentive act. Part of the meaning of a conscious state is that I know in that state when I am in that state. Consciousness is here conceived as a ‘phosphorescence’ attached to some mental occurrence and in no need of a subsequent illustration to reveal itself. Of course, if introspection is defined as a distinct act then reflexive models are really accounts of the first-person access that makes no appeal to introspection.

(3) Public-mind theories and fallibility/infallibility models - the physicalists’ denial of metaphysically private mental facts naturally suggests that ‘looking within’ is not merely like perception but is perception. For Ryle (1900-76). Mental states are ‘iffy’ behavioural facts which, in principle, are equally accessible to everyone in the same was: One’s own self-awareness therefore is, in effect, no different in type from anyone else’s observations about one’s mind.

A more interesting move is for the physicalists to retain the truism that I grasp that I am sad in a very different way from that in which I know you to be sad. This directedness or non-inferential nature of self-knowledge can be preserved in some physicalists theories of introspection. For instance, Armstrong’s identification of mental states with causes of bodily behaviour and of the latter with brain states, makes introspection the process of acquiring information about such inner physical causes. But since introspection is itself a mental state, it is a process in the brain as well: And since its grasp of the relevant causal information is direct, it becomes a process in which the brain scans itself.

Alternatively, a broadly ‘functionalist’ inclination of what is consented to mental states suggest of the machine-analogue of the introspective situation: A machine-table with the instruction ‘Print: ‘I am in state A’ when in state ‘A’ results in the output ‘I am in state A’ when state ‘A’ occurs. Similarly, if we define mental states and events functionally, we can say that introspection occurs when an occurrence of a mental state ‘M’ directly results in awareness of ‘M’. Observe with care that this way of emphasizing directness yields a non-perceptual and non-observational model of introspection. The machine in printing ‘I am in state A’ does so (when it is not making a ‘verbal mistake’) just because it is in state ‘A’. There is no computation of information or process of ascertaining involved. The latter, at best, consist simply in passing through a sequence of states.

Furthering towards the legitimate question: How do I know that I am seeing a spider? Was interpreted as a demand for the faculty or information-processing-mechanism whereby I come to acquire this knowledge? Peculiarities of first-person psychological awareness and reports were carried over as peculiarities of this mechanism. However, the question need not demand the search for a method of knowing but rather for an explanation of the special epistemic features of first-person psychological statements. In that, the problem of introspection (as a way of knowing) dissolves but the problem of explaining ‘introspective’ or first-person authority remains.

Traditionally, belief has been of epistemological interest in its propositional guise: ‘S’ believes that ‘p’, where ‘p’ is a proposition towards which an agent, ‘S’, exhibits an attitude of acceptance. Not all belief is of this sort. If I trust what you say, I believe you. And someone may believe in Mrs. Collins, or in a free-market economy, or in God. It is sometimes supposed that all beliefs are ‘reducible’ to propositional belief, belief-that. Thus, my believing you might be thought as matter of my believing, perhaps, that what you say is true, and your belief in free markets or in God, a matter of your believing that free-market economy is desirable or that God exists.

It is doubtful, however, that non-propositional believing can, in every case, be reduced in this way. Debated on this point has tended to focus on an apparent distinction between ‘belief-that’ and ‘belief-in’, and the application of this distinction to belief in God: St. Thomas Aquinas (1225-64), accepted or advanced as true or real on the basis of less than convincing evidence in supposing that to believe in God is simply to believe that certain truths hold, such that God exists, that he is benevolent, etc. Others ague that belief-in is a distinctive attitude, one that includes essentially an element of trust. More commonly, belief-in has been taken to involve a combination of propositional belief together with some further attitude.

H.H. Price (1969) defends the claim that there is different sorts of belief-in, some, but not all, reducible to beliefs-that. If you believe in God, you believe that God exists, that God is good, etc. But, according to Price, your belief involves, in addition, a certain complex pro-attitude toward its object. One might attempt to analyse this further attitude in terms of additional beliefs-that: ‘S’ believes in ‘χ’ exists (and perhaps holds further factual beliefs about ‘χ’) (2) ‘S’ believes that ‘χ; is good or valuable in some respect? ; and (3) ‘S’ believes that χ’s being good or valuable in this respect is it is a good thing. An analysis of this sort, however, fails adequately to capture the further affective component of belief-in. Thus, according to Price, if you believe in God, your belief is merely that certain truths hold: You possess, in addition, an attitude of commitment and trust towards God.

Notoriously, belief-in outruns the evidence for the corresponding belief-that. Does this diminish its rationality? If belief-in presupposes belief-that, it might be thought that the evidential standards for the former must be, at least, as, high as standards for the latter. And any additional pro-attitude might be thought to require further layers of justification not required for cases of belief-that.

Some philosophers have argued that, at least for cases in which belief-in is synonymous with faith (or, faith-in), evidential thresholds for constituent propositional beliefs are diminished. You may reasonably have faith in God or Mrs. Collins, even though beliefs about their respective attributes, were you to harbour them would be evidentially standard.

Belief-in may be, in general, less susceptible to alteration in the face of unfavourable evidence than belief-that. A believer who encounters evidence against God’s existence may remain unshaken in his belief, in part because the evidence does not bear in his pro-attitude. So long as this is united with his belief that God exists, the belief may survive epistemic buffeting - and reasonably so - in a way that an ordinary propositional belief that would not.

What is at stake here is the appropriateness of distinct types of explanation. That ever since the times of Aristotle (384-322 Bc) philosophers have emphasized the importance of explanatory knowledge. In simplest terms, we want to know not only what is the case but also why it is. This consideration suggests that we define explanation as an answer to a why-question. Such a definition would, however, be too broad, because some why-questions are request for consolation (Why did my son have to die?) Or moral justification (Why should women not be paid the same as men for the same work?) It would also be too narrow because some explanations are responses to how-questions (How does radar work?) Or how-possibly-questions (How is it possible for cats always to land on four feet?)

In its overall sense, ‘to explain’ means to make clear, to make plain, or to provide understanding. Definitions of this sort used philosophically un-helped, for the terms used in the definitions are no less problematic than the term to be defined. Moreover, since a wide variety of things require explanation, and since many different types of explanation exist, a more complex explanation is required. The term ‘explanandum’ is used to refer to that which is to be explained: The term ‘explanans’ aims to that which does the explaining. The explanans and the explanandum taken together constitute the explanation.

One common type of explanation occurs when deliberate human actions are explained in terms of conscionable purposes. ‘Why did you go to the pharmacy yesterday? ‘Because I had a headache and needed to get some aspirin’. It is tacitly assumed that aspirin is an appropriate medication for headaches and that going to the pharmacy would be an efficient way of getting some. Such explanations are, of course, teleological, referring, as they do to goals. The explanans are not the realisation of a future goal - if the pharmacy happened to be closed for stocktaking the aspirin would not have been obtained there, but that would not invalidate the explanation. Some philosophers would say that the antecedent desire to achieve the end is what does the explaining: Others might say that the explaining is done by the nature of the goal and the fact that the action promoted the chances of realizing it. In any case, it should not be automatically assumed that such explanations are causal. Philosophers differ considerably on whether these explanations are to be framed in terms of cause or reason.

The distinction between reason and causes is motivated in good part by a desire to separate the rational from the natural order. Many who have insisted on distinguishing reasons from causes have failed to distinguish two kinds of reason. Consider my reason for sending a letter by express mail. Asked why I did so, I might say I wanted to get it there in a day, or simply: to get it there in a day. Strictly, the reason is expressed by ‘to get it there in a day’. But what this expresses are my reasons only because I am suitably motivated, in that I am in a reason state, wanting to get the letter there in a day. - especially wants reason states, beliefs and intentional - and not reasons strictly so called, that are candidates for causes. The latter are abstract contents of propositional altitudes, as the former are psychological elements that play motivational roles.

It has also seemed to those who deny that reasons are causes that the former justifies, as well as explain the actions for which they are reasons, whereas the role of causes is at most to explain. Another claim is that the relation between reasons (and here reason states are often cited explicitly) and the action they explain is non-contingent: Whereas, the relation of causes to their effects is contingent. The ‘logical connection argument’ proceeds from this claim to the conclusion that reasons are mot causes.

All the same, the explanation as framed in terms of reason and causes, and there are many differing analyses of such concepts as intention and agency. Expanding the domain beyond consciousness. Freud maintained, in addition, that much human behaviour can be explained in terms of unconscious wishes. These Freudian explanations should probably be construed as basically causal.

Problems arise when teleological explanations are offered in other context. The behaviour of non-human animals is often explained in terms of purpose, e.g., the mouse ran to escape from the cat. In such cases the existence of conscious purpose seems dubious. The situation is still more problematic when a super-empirical purpose is invoked -, e.g., the explanation of living species in terms of God’s purpose, or the vitalistic explanation of biological phenomena in terms of an entelechy or vital principle. In recent years an ‘anthropic principle’ has received attention in cosmology. All such explanations have been condemned by many philosophers as anthropomorphic.

The preceding objection, for and all, that philosophers and scientists often maintain that functional explanations play an important and legitimate role in various sciences such as evolutionary biology, anthropology and sociology. For example, the case of the peppered moth in Liverpool, the change in colour and back again to the light phase provided adaption to a changing environment and fulfilled the function of reducing predation on the species. In the study of primitive societies anthropologists have maintained that various rituals, e.g., a rain dance, which may be inefficacious in brings about their manifest goals, e.g., producing rain. Actually fulfil the latent function of increasing social cohesion at a period of stress, e.g., theological and/or functional explanations in common sense and science often take pains to argue that such explanations can be analysed entirely in terms of efficient causes, thereby escaping the change of anthropomorphism, yet not all philosophers agree.

Mainly to avoid the incursion of unwanted theology, metaphysics, or anthropomorphism into science, many philosophers and scientist - especially during the first half of the twentieth century - held that science provides only descriptions and predictions of natural phenomena, but not explanations. Beginning in the 1930s, a series of influential philosophers of science - including Karl Pooper (1935) Carl Hempel and Paul Oppenheim (1948) and Hempel (1965) - maintained that empirical science can explain natural phenomena without appealing to metaphysics and theology. It appears that this view is now accepted by a vast majority of philosophers of science, though there is sharp disagreement on the nature of scientific explanation.

The previous approach, developed by Hempel Popper and others became virtually a ‘received view’ in the 1960s and 1970s. According to this view, to give scientific explanation of an natural phenomenon is to show how this phenomenon can be subsumed under a law of nature. A particular rupture in a water pipe can be explained by citing the universal law that water expands when it heated and the fact that the temperature of the water in the pipe dropped below the freezing point, so began the contraction of structural composites that sustain the particular metal. General laws, as well as particular facts, can be explained by subsumption. The law of conservation of linear momentum can be explained by derivation from Newton’s second and third laws of motion. Each of these explanations is a deductive argument: The premisses constitute the explanans and the conclusion is the explanandum. The explanans contain one or more statements of universal laws and, in many cases, statements describing initial conditions. This pattern of explanation is known as the ‘deductive-nomological model’ any such argument shows that the explanandum had to occur given the explanans.

Moreover, in contrast to the foregoing views - which stress such factors as logical relations, laws of nature and causality - a number of philosophers have argued that explanation, and not just scientific explanation, can be analysed entirely in pragmatic terms.

During the past half-century much philosophical attention has been focussed on explanation in science and in history. Considerable controversy has surrounded the question of whether historical explanation must be scientific, or whether history requires explanations of different types. Many diverse views have been articulated: the foregoing brief survey does not exhaust the variety.

In everyday life we encounter many types of explanation, which appear not to raise philosophical difficulties, in addition to those already of mention. Prior to take-off a flight attendant explains how to use the safety equipment on the aeroplane. In a museum the guide explains the significance of a famous painting. A mathematics teacher explains a geometrical proof to be a bewildered student. A newspaper story explains how a prisoner escaped. Additional examples come easily to mind. The main point is to remember the great variety of context in which explanations are sought and given.

Another item of importance to epistemology is the widely held notion that non-demonstrative inference can be characterized as the inference to the best explanation. Given the variety of views on the nature of explanation, this popular slogan can hardly provide a useful philosophical analysis.

The inference to the best explanation is claimed by many to be a legitimate form of non-deductive reasoning, which provides an important alternative to both deduction and enumerative induction. Some would claim it is only through reasoning to the best explanation that one can justify beliefs about the external world, the past, theoretical entities in science, and even the future. Consider belief about the external world and assume that we know what we do about our subjective and fleeting sensations. It seems obvious that we cannot deduce any truths about the existence of physical objects from truths describing the character of our sensations. But neither can we observe a correlation between sensations and something other than sensations since by hypothesis all we have to rely on ultimately is knowledge of our sensations. Nonetheless, we may be able to posit physical objects as the best explanation for the character and order of our sensations. In the same way, various hypotheses about the past might best explain present memory: Theatrical postulates in physics might best explain phenomena in the macro-world, and it is possible that our access to the future is through past observations. But what exactly is the form of an inference to the best explanation?

When one presents such an inference in ordinary discourse it often seems to have as of:

1. ‘O’ is the case

2. If ‘E’ had been the case ‘O’ is what we would expect,

Therefore there is a high probability that:

3. ‘E’ was the case.

This is the argument form that Peirce (1839-1914) called ‘hypophysis’ or ‘abduction’. To consider a very simple example, we might upon coming across some footsteps on the beach, reason to the conclusion that a person walking along the beach recently by noting that if a person had walked along the beach one would expect to find just such footsteps.

But is abduction a legitimate form of reasoning? Obviously, if the conditional in (2) above is read as a material conditional such arguments would be hopelessly based. Since the proposition that ‘E’ materially implies ‘O’ is entailed by ‘O’, there would always be an infinite number of competing inferences to the best explanation and none of them would seem to lend support to its conclusion. The conditionals we employ in ordinary discourse, however, are seldom, if ever, material conditionals. Such that the vast majority of ‘if . . . Then . . . ‘ statements do not seem to be truth-functionally complex. Rather, they seem to assert a connection of some sort between the states of affairs referred to in the antecedent (after the ‘if’) and in the consequent (after the ‘then’). Perhaps the argument form has more plausibility if the conditional is read in this more natural way. But consider an alternative footsteps explanation:

1. There are footprints on the beach

2. If cows wearing boots had walked along the beach recently one would expect to find such footprints

Therefore. There is a high probability that:

3. Cows wearing boots walked along the beach recently.

This inference has precisely the same form as the earlier inference to the conclusion that people walked along the beach recently and its premisses are just as true, but we would no doubt regard both the conclusion and the inference as simply silly. If we are to distinguish between legitimate and illegitimate reasoning to the best explanation it would seem that we need a more sophisticated model of the argument form. It would seem that in reasoning to an explanation we need criteria for choosing between alternative explanations. If reasoning to the best explanation is to constitute a genuine alternative to inductive reasoning. It is important that these criteria not be implicit premisses which will convert our argument into an inductive argument. Thus, for example, if the reason we conclude that people rather than cow walked along the beach is only that we are implicitly relying on the premiss that footprints of this sort are usually produced by people,. Then it is certainly tempting to suppose that our inference to the best explanation was really a disguised inductive inference of the form:

1. Most footprints are produced by people.

2. Here are footprints

Therefore in all probability,

3. These footprints were produced by people.

If we follow the suggestion made above, we might construe the form of reasoning to the best explanation, such that:

1. ‘O’ (a description of some phenomenon).

2. Of the set of available and competing explanations E1, E2 . . . , En capable of explaining ‘O’, E1 is the best according to the correct criteria for choosing among potential explanations.

Therefore in all probability,

3. E1.

Here too, is a crucial ambiguity in the concept of the best explanation. It might be true of an explanation E1 that it has the best chance of being correct without it being probable that E1 is correct. If I have two tickets in the lottery and one hundred other people each have one ticket, I am the person who has the best chance of winning, but it would be completely irrational to conclude on that basis that I am likely to win. It is much more likely that one of the other people will win than I will win. To conclude that a given explanation is actually likely to be correct on must hold that it is more likely that it is true than that the distinction of all other possible explanations is correct. And since on many models of explanation the number of potential explanations satisfying the formal requirements of adequate explanation is unlimited. This will be a normal feat.

Explanations are also sometimes taken to be more plausible the more explanatory ‘power’ they have. This power is usually defined in terms of the number of things or more likely, the number of kinds of things, the theory can explain. Thus, Newtonian mechanics were so attractive, the argument goes, partly because of the range of phenomena the theory could explain.

The familiarity of an explanation in terms of explanations is also sometimes cited as a reason for preferring that explanation to less familiar kinds of explanation. So if one provides a kind of evolutionary explanation for the disappearance of one organ in a creature, one should look more favourably on a similar sort of explanation for the disappearance of another organ.

Evaluating the claim that inference to the best explanation constitutes a legitimate and independent argument form. One must explore the question of whether it is a contingent fact that, at least, most phenomena have explanations and that explanations that satisfy a given criterions, simplicities, for example, are more likely to be correct. While it might be nice if the universe were structured in such a way that simple, powerful, familiar explanations were usually the correct explanation, it is difficult to avoid the conclusion that if this is true it would be an empirical fact about our universe discovered only a posteriori. If the reasoning to the explanation relies on such criteria, it seems that one cannot without circularity use reasoning to the best explanation to discover that the reliance on such criteria is safe. But if one has some independent way of discovering that simple, powerful, familiar explanations are more often correct, then why should we think that reasoning to the best explanation is an independent source of information about the world? Again, why should we not conclude that it would be more perspicuous to represent the reasoning this way:

1. Most phenomena have the simplest, most powerful, familiar explanations available

2. Here is an observed phenomenon, and E1 is the simplest, most powerful, familiar explanation available.

Therefore, in all probability,

3. This is to be explained by E1.

But the above is simply an instance of familiar inductive reasoning.

There are various ways of classifying mental activities and states. One useful distinction is that between the propositional attitudes and everything else. A propositional attitude in one whose description takes a sentence as complement of the verb. Belief is a propositional attitude: One believes (truly or falsely as the case may be), that there are cookies in the jar. That there are cookies in the jar is the proposition expressed by the sentence following the verb. Knowing, judging, inferring, concluding and doubts are also propositional attitudes: One knows, judges, infers, concludes, or doubts that a certain proposition (the one expressed by the sentential complement) is true.

Though the propositions are not always explicit, hope, fear, expectation. Intention, and a great many others terms are also (usually) taken to describe propositional attitudes, one hopes that (is afraid that, etc.) there are cookies in the jar. Wanting a cookie is, or can be construed as, a propositional attitude: Wanting that one has (or eat or whatever) a cookie, intending to eat a cookie is intending that one will eat a cookie.

Propositional attitudes involve the possession and use of concepts and are, in this sense, representational. One must have some knowledge or understanding of what χ’s are in order to think, believe or hope that something is ‘χ’. In order to want a cookie, intend to eat one must, in some way, know or understand what a cookie is. One must have this concept. There is a sense in which one can want to eat a cookie without knowing what a cookie is - if, for example, one mistakenly thinks there are muffins in the jar and, as a result wants to eat what is in the jar (= cookies). But this sense is hardly relevant, for in this sense one can want to eat the cookies in the jar without wanting to eat any cookies. For this reason(and this sense) the propositional attitudes are cognitive: They require or presuppose a level of understanding and knowledge, this kind of understanding and knowledge required to possess the concepts involved in occupying the propositional state.

Thought there is sometimes disagreement about their proper analysis, non-propositional mental states, yet do not, at least on the surface, take propositions as their object. Being in pain, being thirsty, smelling the flowers and feeling sad are introspectively prominent mental states that do not, like the propositional attitudes, require the application or use of concepts. One doesn’t have to understand what pain or thirst is to experience pain or thirst. Assuming that pain and thirst are conscious phenomena, one must, of course, be conscious or aware of the pain or thirst to experience them, but awareness of must be carefully distinguished from awareness that. One can be aware of ‘χ’, - thirst or a toothache - without being aware that, that, e.g., thirst or a toothache, is that like beliefs that and knowledge that, are a propositional attitude, awareness of is not.

As the examples, pain, thirst, tickles, itches, hungers are meant to suggest, the non-propositional states have a felt or experienced [‘phenomenal’] quality to them that is absent in the case of the propositional attitudes. Aside from who it is we believe to be playing the tuba, believing that John is playing the tuba is much the same as believing that Joan is playing the tuba. These are different propositional states, different beliefs, yet, they are distinguished entirely in terms of their propositional content - in terms of what they are beliefs about. Contrast this with the difference between hearing John play the tuba and seeing him play the tuba. Hearing John play the tuba and seeing John play the tubas differ, not just (as do beliefs) in what they are of or about (for these experiences are, in fact, of the same thing: John playing the tuba), but in their qualitative character, the one involves a visual, the other an auditory, experience. The difference between seeing John play the tuba and hearing John play the tuba, is then, a sensory not a cognitive deviation.

Some mental states are a combination of sensory and cognitive elements, e.g., as fears and terror, sadness and anger, feeling joy and depression, are ordinarily thought of in this way sensations are: Not in terms of what propositions (if any) they represent, but (like visual and auditory experience) in their intrinsic character, as they are felt to the someone experiencing them. But when we describe a person for being afraid that, sad that, upset that (as opposed too merely thinking or knowing that) so-and-so happened, we typically mean to be describing the kind of sensory (feeling or emotional) quality accompanying the cognitive state. Being afraid that the dog is going to bite me is both to think (that he might bite me) - a cognitive state - and feel fear or apprehension (sensory) at the prospect.

The perceptual verbs exhibit this kind of mixture, this duality between the sensory and the cognitive. Verbs like ‘to hear’, ‘to say’, and ‘to feel’ is [often] used to describe propositional (cognitive) states, but they describe these states in terms of the way (sensory) one comes to be in them. Seeing that there are two cookies left by seeing. Feeling that there are two cookies left is coming to know this in a different way, by having tactile experiences (sensations).

On this model of the sensory-cognitive distinction (at least it is realized in perceptual phenomena). Sensations are a pre-conceptual, a pre-cognitive, vehicle of sensory information. The terms ‘sensation’ and ‘sense-data’ (or simply ‘experience’) were (and, in some circles, still are) used to describe this early phase of perceptual processing. It is currently more fashionable to speak of this sensory component in perception as the percept, the sensory information store, is generally the same: An acknowledgement of a stage in perceptual processing in which the incoming information is embodied in ‘raw’ sensory (pre-categorical, pre-recognitional) forms. This early phase of the process is comparatively modular - relatively immune to, and insulated from, cognitive influence. The emergence of a propositional [cognitive] states - seeing that an object is red - depends, then, on the earlier occurrence of a conscious, but nonetheless, non-propositional condition, seeing (under the right condition, of course) the red object. The sensory phase of this process constitutes the delivery of information (about the red object) in a particular form (visual): Cognitive mechanisms are then responsible for extracting and using this information - for generating the belief (knowledge) that the object is red. (The belief of blindness suggests that this information can be delivered, perhaps in degraded form, at a non-conscious level.)

To speak of sensations of red objects, tubas and so forth, is to say that these sensations carry information about an object’s colour, its shape, orientation, and position and (in the case of audition) information about acoustic qualities such as pitch, timbre, volume. It is not to say that the sensations share the properties of the objects they are sensations of or that they have the properties they carry information about. Auditory sensations are not loud and visual sensations are not coloured. Sensations are bearers of nonconceptualized information, and the bearer of the information that something is red need not itself be red. It need not even be the sort of thing that could be red: It might be a certain pattern of neuronal events in the brain. Nonetheless, the sensation, though not itself red, will (being the normal bearer of the information) typically produce in the subject who undergoes the experience a belief, or tendency to believe, that something red is being experienced. Hence the existence of hallucinations.

Just as there are theories of the mind, that would deny the existence of any state of mind whose essence was purely qualitative (i.e., did not consists of the state’s extrinsic, causal, properties) there are theories of perception and knowledge - cognitive theories - that denies a sensory component to ordinary sense perception. The sensor y dimension (the look, feel, smell, taste of things) is (if it is not altogether denied) identified with some cognitive condition (knowledge or belief) of the experienced. All seeing (not to mention hearing, smelling and feeling) becomes a form of believing or knowing. As a result, organisms that cannot know cannot have experiences. Often, to avoid these striking counterintuitive results, implicit or otherwise unobtrusive (and, typically, undetectable) forms of believing or, knowing.

Aside, though, from introspective evidence (closing and opening one’s eyes, if it changes beliefs at all, doesn’t just change beliefs, it eliminates and restores a distinctive kind of conscionable experience), there is a variety of empirical evidence for the existence of a stage in perceptual processing that is conscious without being cognitive (in any recognizable sense). For example, experiments with brief visual displays reveal that when subjects are exposed for very brief (50 msec.) Intervals to information-rich stimuli, there is persistence (at the conscious level) of what is called an image or visual icon that embodies more information about the stimulus than the subject can cognitively process or report on. Subjects cab exploit the information in this persisting icon by reporting on any part of the absent array of numbers (the y can, for instance, reports of the top three numbers, the middle three or the bottom three). They cannot, however, identify all nine numbers. The y report seeing all nine, and the y can identify any one of the nine, but they cannot identify all nine. Knowledge and brief, recognition and identification - these cognitive states, though present for any two or three numbers in the array, are absent for all nine numbers in the array. Yet, the image carries information about all nine numbers (how else accounts for subjects’ ability to identify any number in the absent array?) Obviously, then, information is there, in the experience itself, whether or not it is, or even can be. As psychologists conclude, there is a limit on the information processing capacities of the latter (cognitive) mechanisms that are not shared by the sensory stages themselves.

Perceptual knowledge is knowledge acquired by or through the senses. This includes most of what we know. Some would say it includes everything we know. We cross intersections when we see the light turn green, head for the kitchen when we smell the roast burning, squeeze the fruit to determine its ripeness, and climb out of bed when we hear the alarm, ring. In each case we come to know something - that the light has turned green, that the roast is burning, that the melon is overripe, and that it is time to get up - that the light has turned green - by use of the eyes. Feeling that the melon is overripe in coming to know a fact - that the melon is overripe - by one’s sense of touch. In each case the resulting knowledge is somehow based on, derived from or grounded in the sort of experience that characterizes the sense modality in question.

Seeing a rotten kumquat is not at all like the experience of smelling, tasting or feeling a rotten kumquat. Yet all these experiences can result in the same knowledge - Knowledge that the kumquat is rotten. Although the experiences are much different, they must, if they are to yield knowledge, embody information about the kumquat: The information that it is rotten. Seeing that the fruit is rotten differs from smelling that it is rotten, not in what is known, but how it is known. In each case, the information has the same source - the rotten kumquat -, but it is, so top speak, delivered via different channels and coded and re-coded in different experiential neuronal excitations as stimulated sense attractions.

It is important to avoid confusing perceptual knowledge of facts, e.g., that the kumquat is rotten, with the perception of objects, e.g., rotten kumquats. It is one thing ro see (taste, smell, feel) a rotten kumquat, and quite another to know (by seeing or tasting) that it is a rotten kumquat. Some people, after all, don not know what kumquats look like. They see a kumquat but do not realize (do mot see that) it is a kumquat. Again, some people do not know what a kumquat smell like. They smell a rotten kumquat and - thinking, perhaps, that this is a way this strange fruit is supposed to smell - does not realize from the smell, i.e., do not smell that it is a rotted kumquat. In such cases people see and smell rotten kumquats - and in this sense perceive rotten kumquat - and never know that they are kumquats - let alone rotten kumquats. They cannot, not at least by seeing and smelling, and not until they have learned something about (rotten) kumquats. Since the topic as such is incorporated in the perceptual knowledge - knowing, by sensory means, that something if ‘F’ -, we will be primary concerned with the question of what more, beyond the perception of F’s, is needed to see that (and thereby know that) they are ‘F’. The question is, however, not how we see kumquats (for even the ignorant can do this) but, how we know (if, that in itself, that we do) that, that is what we see.

Much of our perceptual knowledge is indirect, dependent or derived. By this is that it is meant that the facts we describe ourselves as learning, as coming to know, by perceptual means are pieces of knowledge that depend on our coming to know something else, some other fat, in a more direct way. We see, by the gauge, that we need gas, see, by the newspapers, that our team has lost again, or see, by her expression that is nervous. This derived or dependent sort of obtainable knowledge is particularly prevalent in the case of vision but it occurs, to a lesser degree, in every sense modality. We install bells and other noise-makers so that we can, for example, hear (by the bells) that someone is at the door and (by the alarm) that its time to get away. When we obtain knowledge in this way. It is clear that unless one sees - hence, comes to know. Something about the gauge (that it reads ‘empty’), the newspaper (which is says) and the person’s expression, one would not see (hence, know) what one is described as coming to know by perceptual means. If one cannot hear that the bell is ringing, one cannot - not at least in this way - hear that one’s visitors have arrived. In such cases one sees (hears, smells, etc.) that ‘a’ is ‘F’, coming to know thereby that ‘a’ is ‘F’, by seeing (hearing, etc.) that some other condition, b’s being ‘G’, obtains. When this occurs, the knowledge (that ‘a’ is ‘F’) is derived, or dependent on, the more basic perceptual knowledge that ‘b’ is ‘G’.

Though perceptual knowledge about objects is often, in this way, dependent on knowledge of fats about different objects, the derived knowledge is sometimes about the same object. That is, we see that ‘a’ is ‘F’ by seeing, not that some other object is ‘G’, but that ‘a’ itself is ‘G’. We see, by her expression, that she is nervous. She tells that the fabric is silk (not polyester) by the characteristic ‘greasy’ feel of the fabric itself (not, as I do, by what is printed on the label). We tell whether it is an oak tree, a Porsche, a geranium, an igneous rock or a misprint by its shape, colour, texture, size, behaviour and distinctive markings. Perceptual knowledge of this sort is also deprived - derived from the more basic facts (about ‘a’) we use to make the identification. In this case the perceptual knowledge is still indirect because, although the same object is involved, the facts we come to know about it are different than the facts that enable us to know it.

Derived knowledge is sometimes described as inferential, but this is misleading, at the conscious level there is no passage of the mind from premise to conclusion, no reasoning, no problem-solving. The observer, the one who sees that ‘a’ is ‘F’ by seeing that ‘b’ (or ‘a’ itself) is ‘G’, need not be (and typically is not) aware of any process of inference, any passage of the mind from one belief to another. The resulting knowledge, though logically derivative, is psychologically immediate. I could see that she was getting angry: so, I moved my hand. I did not, - at least not at any conscious level - infers (from her expression and behaviour) that she was getting angry. I could (or, so it seemed to me) see that she was getting angry. It is this psychological immediacy that makes indirect perceptual knowledge a species of perceptual knowledge.

The psychological immediacy that characterises so much of our perceptual knowledge - even (sometimes) the most indirect and derived forms of it - does not mean that learning is not required to know in this way. One is not born with (may, in fact, never develop) the ability to recognize daffodils, muskrats and angry companions. It is only after a long experience that one is able visually to identify such things. Beginners may do something corresponding to inference: They recognize relevant features of trees, birds, and flowers, factures they already know how to perceptually identify, and then infer (conclude), on the basis of what they see, and under the guidance of more expert observers, that its an oak a finch or a geranium. But the experts (and we are all experts on many aspects of our familiar surroundings) do not typically go through such a process. The expert just sees that its an oak, a finch or a geranium. The perceptual knowledge of the expert is still dependent, of course, since even an expert cannot see what kind of flower it is if she cannot first see its colour and shape, but it is to say, that the expert has developed identificatory skills that no longer require the sort of conscious inferential processes that characterize a beginner’s efforts.

Coming to know that ‘a’ is ‘F’ by seeing that ‘b’ is ‘G’ obviously requires some background assumption on the part of the observer, an assumption to the effect that ‘a’ is ‘F’ (or perhaps only probable ‘F’) when ‘b’ is ‘G’. If one does not assume (as taken to be granted) that the gauge is properly connected, and does not, thereby assume that it would not register ‘empty’,unless the tank was nearly empty, then even if one could see that it registered ‘empty’, one would not learn ( hence, would not see) that one needed gas. At least, one would not see it by consulting the gauge. Likewise, in trying to identify birds, its no use being able to see their markings if one doesn’t know something about which birds have which marks - sometimes of the form: A bird with these markings is (probably) a finch.

It would seem, moreover, that these background assumptions, if they are to yield knowledge that ‘a’ is ‘F’, as they must if the observer is to see (by b’s being ‘G’) that ‘a’ is ‘F’, must themselves qualify as knowledge. For if this background fact is not known, if it is not known whether ‘a’ is ‘F’ when ‘b’ is ‘G’, then the knowledge of b’s being ‘G’, taken by itself, powerless to generate the knowledge that ‘a; is ‘F’. If the conclusion is to be known to be true, both the premises used to reach that conclusion must be known to be true. Or so it would seem.

Externalism/Internalism are most generally accepted of this distinction if that a theory of justification is internalist, if and only if it requires that all of the factors needed for a belief to be epistemically justified for a given person be cognitively accessible to that person. Internal to his cognitive perspective, and external, if it allows that, at least, part of the justifying factor need not be thus accessible, so they can be external to the believers’ cognitive perspective, beyond his understanding. As complex issues well beyond our perception to the knowledge or an understanding, however, epistemologists often use the distinction between internalist and externalist theories of epistemic justification without offering any very explicit explication.

The externalism/internalism distinction has been mainly applied to theories of epistemic justification. It has also been applied in a closely related way to accounts of knowledge and in a rather different way to accounts of belief and thought content.

The internalist requirement of cognitive accessibility can be interpreted in at least two ways: A strong version of internalism required that the believer actually be aware of the justifying factor in order to be justified: While a weaker version would require only that he be capable of becoming aware of them by focussing his attention appropriately, but without the need for any change of position, new information etc. Though the phrase ‘cognitively accessible’ suggests the weak for internalism, wherefore, the idea that epistemic justification requires that the believer actually have in his cognitive possession a reason for thinking that the belief is true.

It should be carefully noticed that when internalism is construed by either that the justifying factors literally are internal mental states of the person or that the internalism. On whether actual awareness of the justifying elements or only the capacity to become aware of them is required, comparatively, the consistency and usually through a common conformity brings upon some coherentists views that could also be internalist, if both the belief and other states with which a justification belief is required to cohere and the coherence relations themselves are reflectively accessible. In spite of its apparency, it is necessary, because on at least some views, e.g., a direct realist view of perception, something other than a mental state of the believer can be cognitively accessible, not sufficient, because there are views according to which at least, some mental states need not be actual (strong versions) or even possible (weak versions) objects of cognitive awareness.

Obviously too, a view that was externalist in relation to a strong version of internalism (by not requiring that the believer actually be aware of all justifying factors) could still be internalist in relation to a weak version (by requiring that, at least, be capable of becoming aware of them).

The most prominent recent externalist views have been versions of ‘reliabilism’, whose main requirement for justification is roughly that the beliefs be produced in a way or to a considerable degree in which of subject matter conducting a process that makes of objectively likely that the belief is true. What makes such a view externalist is the absence of any requirement that the person for whom the belief is justified have any sort of cognitive access to the relation of reliability in question. Lacking such access, such a person will in general have no reason for thinking that the belief is true or likely to be true, but will, on such an account, nonetheless, be epistemically justified in accepting it. Thus, such a view arguably marks a major break from the modern epistemological tradition, stemming from Descartes, which identifies epistemic justification with having a reason, perhaps, even a conclusive reason, for thinking that the belief is true. An epistemologist working within this tradition is likely to feel that the externalist, than offering a competing account of the same concept of epistemic justification with which the traditional epistemologist is concerned, has simply changed the subject.

An alterative to giving an externalist account of epistemic justification, one which may be more defensible while still accommodating many of the same motivating concerns, is especially given to some externalists account of knowledge directly, without relying on an intermediate account of justification. Such a view will obviously have to reject the justified true belief account of knowledge, holding instead that knowledge is true belief which satisfies the chosen externalist condition, e.g., is a result of a reliable process, and, perhaps, further conditions as well. This makes it possible for such a view to retain an internalist account of epistemic justification, though the centralities are seriously diminished. Such an externalist account of knowledge can accommodate the common-sense conviction that animals, young children and unsophisticated adults possess knowledge though not the weaker conviction that such individuals are epistemically justified in their belief. It is also, at least. Vulnerable to internalist counter-examples, since the intuitions involved there pertains more clearly to justification than to knowledge, least of mention, as with justification and knowledge, the traditional view of content has been strongly internalist in character. An objection to externalist accounts of content is that they seem unable to do justice to our ability to know the content of our beliefs or thoughts ‘from the inside’, simply by reflection. So, then, the adoption of an externalist account of mental content would seem as if part of all of the content of a belief is inaccessible to the believer, then both the justifying status of other beliefs in relation to that content and the status of the content as justifying further beliefs will be similarly inaccessible, thus contravening the internalist requirements for justification.

Externalists, however, argue that the indirect knowledge that ‘a’ is ‘F’, though it may depend on the knowledge that ‘b’ is ‘G’, does not require knowledge of the connecting fact, the fact that ‘a’ is ‘F’ when ‘b’ is ‘G’. Simple belief (or, perhaps, justified belief, there is stronger and weaker versions of externalism) in the connecting fact is sufficient to confer a knowledge of the fact is sufficient to confer a knowledge e of the connected fact. Even if, strictly speaking, I don’t know she is nervous whenever she fidgets like that, I can nonetheless, see and hence know, that she is nervous by the way she fidgets, if I (correctly) assume that his behaviour r is a reliable expression of nervousness. One need not know the gauge is working well to make observations (acquire observational knowledge) with it. All that is required, besides the observer believing that the gauge is reliable, is that the gauge, in fact, be reliable, i.e., that the observer’s background beliefs be true. Critics of externalisms have been quick to point out that this theory has the unpalatable consequence that knowledge can be made possible by - and, in this sense, be made to rest on - lucky hunches (that turn out true) and unsupported (even irrational) beliefs. Surely, internalist argue, if one is going t o know that ‘a’ is ‘F’ on the basis of b’s being ‘G’, one should have (as a bare minimum) some justification for thinking that ‘a’ is ‘F’, or is probably ‘F’, when ‘b’ is ‘G’.

Whatever view one takes about these matters (with the possible exception of extreme externalism) indirect perception obviously requires some understanding (knowledge? Justification? Belief?) of the general relationship between the fact one comes to know (that ‘a’ is ‘F’) and the facts (that ‘b’ is ‘G’) that enable one to know it. And it is this requirement on background knowledge or understanding that leads to questions to questions about the possibility of indirect perceptual knowledge. Is it really knowledge? The first question is inspired by sceptical doubts about whether we can ever know the connecting facts in question. How is it possible to learn, to acquire knowledge of, the connecting facts knowledge of which is necessary to see,. By b’s being ‘G’, and that ‘a’ is ‘F’? These connecting facts do not appear to be perceptually knowable. Quite the contrary, they appear to b e general truths knowable (if knowable at all) by inductive inference e from past observations. And if one is sceptical about obtaining knowledge in this indirect, inductive way one is, perforce, sceptical about the existence of the kind of indirect knowledge, including indirect perceptual knowledge of the set described, in that depends on it.

Even if one puts aside such sceptical questions, however, they’re remains a legitimate concern about the perceptual character of this kind knowledge. If one sees that ‘a’ is ‘F’ by seeing that ‘b’ is ‘G’, is really seeing that ‘a’ is ‘F’? Isn’t perception merely a part - and, from an epistemological standpoint, the less significant part - of the process whereby one comes to know that ‘a’ is ‘F’. One must, it is true, sere that ‘b’ is ‘G’, but this is only one of the premises needed to reach the conclusion (knowledge) that ‘a’ is ‘F’. There is also the background knowledge that is essential to the process. If we think of a theory as any factual proposition, or set of factual propositions, that cannot itself be known in some direct observational way, we can express this worry by saying that indirect perception is always theory-loaded: Seeing (indirectly)that ‘a’ is ‘F’ is only possible if the observer already has knowledge of (justification for, belief in) some theory, the theory ‘connecting’ the fast one cannot come to know (that ‘a’ is ‘F’) with the fact (that ‘b’ is ‘G’) that enables one to know it.

This, of course, reverses the standard foundationalist picture of human knowledge. Instead of theoretical knowledge depending on, and being derived from, perception, perception (of the indirect sort) presupposes a prior knowledge.

Foundationalists are quick to point out that this apparent reversal in the structure of human knowledge is only apparent. Our indirect perception of facts depends on theory, yes, but this merely shows that indirect perceptual knowledge is not part of the foundation. To reach the kind of perceptual knowledge that lies at the foundation, we need to look at a form of perception that is purified of all theoretical elements. This then, will be perceptual knowledge pure and direct. No background knowledge or assumptions about connecting regularities are needed in direct perception because the known facts are presented directly and immediately and not (as, in indirect perception) on the basis of some other facts. In direct perception all the justification (needed for knowledge) is right there in the experience itself.

What, then, about the possibility of perceptual knowledge pure and direct, the possibility of coming to know, on the basis of sensory experience, that ‘a’ is ‘F’ where this does not require assumptions or knowledge that has a source outside the experience itself? Where is this epistemological ‘pure gold’ to be found?

There are, basically, two views about the nature of direct perceptual knowledge (coherentists would deny that any of our knowledge is basic in this sense). These views (following traditional nomenclature) can be called ‘direct realism’ and ‘representationalism’ or ‘representative realism’. A representationalist restricts direct perceptual knowledge to objects of a very special sort: Ideas, impressions, or sensations, sometimes called sense-data - entities in the mind of the observer. One directly perceives a fact, e.g., that ‘b’ is ‘G’ , only when ‘b’ is a mental entity of some sort - a subjective appearance or sense-data - and ‘G’ is a property of this datum. Knowledge of these sensory states is supposed to be certain and infallible. These sensory facts are, so o speak, right up against the mind’s eye. One cannot be mistaken about these facts for these facts are, in reality, facts about the way things appear to be, and one cannot be mistaken about the way things appear to be. Normal perception of external conditions, then, turns out to be (always) a type of indirect perception. One ‘sees’ that there is a tomato in front of one by seeing that the appearance (of the tomato) have a certain quality (reddish and bulgy) and inferring as this is topically said to be automatic and unconscious, on the basis of certain background assumptions, e.g., that there typically is a tomato in front of one when one has experiences of this sort, that there is a tomato in front of one. All knowledge of objective reality, then, even what commonsense regards as the most direct perceptual knowledge, is based on an even more direct knowledge of the appearances.

For the representationalist, then, perceptual knowledge of our physical surroundings is always theory-loaded and indirect. Such perception is ‘loaded’

with the theory that there is some regular, some uniform, correlation between the way things appear (known in the perceptually direct way) and the way things actually are (known, if known at all, in a perceptual indirect way).

The second view, direct realism, refuses to restrict perceptual knowledge, to an inner world of subjective experience. Though the direct realist is willing to concede that much of our knowledge of the physical world is indirect, however, direct and immediate it may sometimes feel, some perceptual knowledge of physical reality is direct. What makes it direct is that such knowledge is not based on, nor in any way dependent on, other knowledge and belief. The justification needed for the knowledge is right there in the experience itself.

To understand the way this is supposed to work, consider an ordinary example, ‘S’ identifies a banana (learns that it is a banana) by noting its shape and colour - perhaps, even tasting and smelling it (to make sure its not wax). In this case the perceptual knowledge that is a banana is (the direct realist admits) indirect, dependence on S’s perceptual knowledge of its shape, colour, smell, and taste. ‘S’ learns that it is a banana by seeing that it is yellow, banana-shaped, etc. Nonetheless, S’s perception of the banana’s colour and shape is not indirect. ‘S’ does not see that the object is yellow, for example, by seeing, knowing, believing anything more basic - either about the banana or anything else, e.g., his own sensations of the banana. ‘S’ has learned to identify such features, of course, but when ‘S’ learned to do is not an inference, even a unconscious inference, from other things be believes. What ‘S’ acquired was a cognitive skill, a disposition to believe of yellow objects he saw that they were yellow. The exercise of this skill does not require, and in no way depends on having of any other beliefs. S’s identificatorial successes will depend on his operating in certain special conditions, of course, ‘S’ will not, perhaps, be able to visually identify yellow objects in drastically reduced lighting, at funny viewing angles, or when afflicted with certain nervous disorders. But these facts about ‘S’ can see that something is yellow does not show that his perceptual knowledge (that ‘a’ is yellow) in any way deepens on a belief )let alone knowledge) that he is in such special conditions. It merely shows that direct perceptual knowledge is the result of exercising a skill, an identificatorial skill, that like any skill,. Requires certain conditions for its successful exercise. An expert basketball player cannot shoot accurately in a hurricane. He needs normal conditions to do what he has learned to do. So also, with individuals who have developed perceptual (cognitive) skills. They need normal conditions to do what they have learned to do. They need normal conditions to see, for example, that something is yellow. But they do not, any more than the basketball player, have to know they are in these conditions to do what being in these conditions enables them to do.

This means, of course, that for a direct realist direct perceptual knowledge is fallible and corrigible. Whether ‘S’ sees that ‘a’ is ‘F’ depends on his being caused to believe that ’a’ is ‘F’ in conditions that are appropriate for an exercise of that cognitive skill. If conditions are right, then ‘S’ sees (hence, knows) that ‘a’ is ‘F’. If they aren’t he doesn’t. Whether or not ‘S’ knows depends, then, not on what else, if anything, ‘S’ believes, but on the circumferences in which ‘S’ comes to believe. This being so, this type of direct realism is a form of externalism, direct perception of objective facts, pure perceptual knowledge of external events, is made possible because what is needed, by way of justification for such knowledge has been reduced. Background knowledge - and, in particular, the knowledge that the experience does, and suffices for knowing - is not needed.

This mans that the foundations of knowledge are fallible. Nonetheless, though fallible, they are in no way derived. That is what makes them foundations. Even if they are brittle, as foundations sometimes are, everything else rests upon them

The theory of representative realism holds that (1) there is a world whose existence and nature is independent of us and of our perceptual experience of it, and (2) perceiving an object located in that external world necessarily involves causally interacting with that object, (3) the information acquired in perceiving an object is indirect: It is information most immediately about the perceptual experience caused in us by the object, and only derivatively about the object itself:

Clause 1. Makes representative realism a species of realism.

Clause 2. Makes it a species of causal theory of perception.

Clause 3. Makes it a species of representative as opposed

to direct realism.

Traditionally, representative realism has been allied with an act/object analysis of sensory experience. Its act/object analysis is traditionally a major plank in arguments for representative realism. According to the act/object analysis of experience with content involves an object of experience to which the subject is related by an act of awareness (the event of experiencing that object). This is meant to apply not only to perceptions, which have material objects (whatever is perceived), but also to experiences like hallucinations and dream experiences, which do not. Such experiences nonetheless, appear to represent something,. And their objects are supposed to be whatever it is that they represent. Act/object theorists may differ on the nature of objects of experience, which have been treated as properties, Meinongian objects (which may not exist or have any form of being), and, more commonly, private mental entities with sensory qualities. (The term ‘sense-data’ is now usually applied to the latter, but has also been used as a general term for objects of sense experiences, as in the work of G.E. Moore.) Act/object theorists may also differ on the relationship between objects of experience and objects of perception. In terms of representative realism, objects of perception (of which we are ‘indirectly aware’). Meinongians, however, may simply treat objects of perception as existing objects of experience.

Realism in any area of thought is the doctrine that certain entities allegedly associated with that area are indeed real. Common sense realism - sometimes called ‘realism’, without t qualification - says that ordinary things like chairs and trees and people are real. Scientific realism says that theoretical posits like electrons and fields of force and quarks are equally real. And psychological realism says mental states like pain and beliefs are real. Realism can be upheld - and opposed - in all such areas, as it can with differently or more finely drawn provinces of discourse: For example, with discourse about colours, about the past, about possibility and necessity, or about matters of moral right and wrong. The realist in any such area insists on the reality of the entities in question in the discourse.

If realism itself can be given a fairly quick characterization, it is more difficult to chart the various forms of opposition, for they are legion. Some opponents deny that there are any distinctive posits associated with the area of discourse under dispute: A good example is the emotivist doctrine that moral discourse does not posit values but serves only, like applause and exclamation, to express feelings. Other opponents deny that entities posited by the relevant discourse exist, or, at least, exists independently of our thinking about them: Here the standard example is ‘idealism’. And others again, insist that the entities associated with the discourse in question are tailored to our human capacities and interests and, to that extent, are as much a product of invention as a matter of discovery.

Nevertheless, one us e of terms such as ‘looks’, ‘seems’, and ‘feels’ is to express opinion. ‘It looks as if the Labour Party will win the next election’ expresses an opinion about the party’s chances and does not describe a particular kind of perceptual experience. We can, however, use such terms to describe perceptual experience divorced from any opinion to which the experience may incline us. A straight-stick half in water looks bent, and does so to people completely familiar with this illusion who has, therefore, no inclination to hold that the stick is in fact bent. Such users of ‘looks’, ‘seems’, ‘taste’, etc. are commonly called ‘phenomenological’.

The act/object theory holds that the sensory experience recorded by sentence employing sense is a matter of being directly acquainted with something which actually bears the red to me. I am acquainted with a red expanse (in my visual field): When something tastes bitter to me I am directly acquainted with a sensation with the property of being bitter, and so on and so forth. (If you do not understand the term ‘directly acquainted’, stick a pin into your finger. The relation you will then bear to your pain, as opposed to the relation of concern you might bear to another’s pain when told about it, is an instance e of direct acquaintance e in the intended sense.)

The act/object account of sensory experience combines with various considerations traditionally grouped under the head of the argument for illusion to provide arguments for representative realism, or more precisely for the clause in it that contents that our senorily derived information about the world comes indirectly, that what we are most directly acquainted with is not an aspect of the world but an aspect for our mental sensory responses to it. Consider, for instance, the aforementioned refractive illusion, that of a straight stick in water looking bent. The act/object account holds that in this case we are directly acquainted with a bent shape. This shape, so the argument runs, cannot be the stick as it is straight, and thus, must be a mental item, commonly called a sense-datum. And, ion general sense-data-visual, tactual, etc. - is held to be the objects of direct acquaintance. Perhaps the most striking uses of the act/object analysis to bolster representative realism turns on what modern science tells us about the fundamental nature of the physical world. Modern science tells us that the objects of the physical world around us are literally made up of enormously many, widely separated, tiny particles whose nature can be given in terms of a small number of properties like mass, charge, spin and so on. (These properties are commonly called the primary qualities, as primary and secondary qualities represent a metaphysical distinction with which really belong to objects in the world and qualities which only appear to belong to them, or which human beings only believe to belong to them, because of the effects those objects produce ion human beings, typically through the sense organs, that is to say, something that does not hold everywhere by nature, but is producing in or contributed by human beings in their interaction with a world which really contains only atoms of certain kinds in a void. To think that some objects in the world are coloured, or sweet ort bitter is to attribute to objects qualities which on this view they do not actually possess. Rather, it is only that some of the qualities which are imputed to objects, e.g., colour, sweetness, bitterness, which are not possessed by those objects. But, of course, that is not how the objects look to us, not how they present to our senses. They look continuous and coloured. What then, can be these coloured expanses with which we are directly acquainted be other than mental sense-data?

Two objections dominate the literature on representative realism: One goes back to Berkeley (1685-1753) and is that representative realism lead straight to scepticism about the external world, the other is that the act/object account of sensory awareness is to be rejected in favour of an adverbial account.

Traditional representative realism is a ‘veil of perception’ doctrine, in Bennett’s (1971) phrase. Lock e’s idea (1632-1704) was that the physical world was revealed by science to be in essence colourless, odourless, tasteless and silent and that we perceive it by, to put it metaphorically, throwing a veil over it by means of our senses. It is the veil we see, in the strictest sense of ‘see’. This does not mean that we do not really see the objects around us. It means that we see an object in virtue of seeing the veil, the sense-data, causally related in the right way to that object, an obvious question to ask, therefore, is what justifies us in believing that there is anything behind the veil, and if we are somehow justified in believing that there is something behind the veil,. How can we be confident of what it is like?

One intuition that lies at the heart of the realist’s account of objectivity is that, in the last analysis, the objectivity of a belief is to be explained by appeal to the independent existence of the entities it concerns: Epistemological objectivity, this is, is to b e analysed in terms of ontological notions of objectivity. A judgement or beliefs is epistemological notions of objectivity, if and only if it stands in some specified reflation to an independently existing determinate reality. Frége (1848-1925), for example, believed that arithmetic could comprise objective knowledge only if the numbers it refers to, the propositions it consists of, the functions it employs, and the truth-values it aims at, are all mind-independent entities. And conversely, within a realist framework, to show that the members of a given class of judgements are merely subjective, it is sufficient to show that there exists no independent reality that those judgements characterize or refer to.

Thus, it is favourably argued that if values are not part of the fabric of the world, then moral subjectivity is inescapable. For the realist, the, of epistemological notions of objectivity is to be elucidated by appeal to the existence of determinate facts, objects, properties, events and the like, which exit or obtain independent of any cognitive access we may have to them. And one of the strongest impulses towards platonic realism - the theoretical commitment to the existence of abstract objects like sets, numbers, and propositions - stems from the widespread belief that only if such things exist in their own right can we allow that logic, arithmetic and science are indeed objective. Though ‘Platonist’ realism in a sense accounts for mathematical knowledge, it postulates such a gulf between both the ontology and the epistemology of science and that of mathematics that realism is often said to make the applicability of mathematics in natural science into an inexplicable mystery

This picture is rejected by anti-realists. The possibility that our beliefs and theories are objectively true is not, according to them, capable of being rendered intelligible by invoking the nature and existence of reality as it is in and of itself. If our conception of epistemological objective notions is minimal, requiring only ‘presumptive universality’, then alternative, non-realist analysers of it can seem possible - and eve n attractive. Such analyses have construed the objectivity of an arbitrary judgement as a function of its coherence with other judgements, of its possession of grounds that warrant it,. Of its conformity to the a prior rules that constitute understanding, of its verifiability (or falsifiability), or if its permanent presence in the mind of God. On e intuitive common to a variety of different anti-realist theories is such that for our assertions to be objective, for our beliefs to comprise genuine knowledge, those assertions and beliefs must be, among other things, rational, justifiable, coherent, communicable and intelligible. But it is hard, the anti-realist claims, to see how such properties as these can be explained by appeal to entities as they are on and of themselves. On the contrary, according to most forms of anti-realism, it is only the basis of ontological subjective notions like ‘the way reality seems to us’, ‘the evidence that is available to us’, ‘the criteria we apply’, ‘the experience we undergo’ or ‘the concepts we have acquired’ that epistemological notions of objectivity of our beliefs can possibly be explained.

The reason by which a belief is justified must be accessible in principle to the subject hold that belief, as Externalists deny this requirement, proposing that this makes knowing too difficult to achieve in most normal contexts. The internalist-Externalists debate is sometimes also viewed as a debate between those who think that knowledge can be naturalized (Externalists) and those who do not (internalist) naturalists hold that the evaluative notions used in epistemology can be explained in terms of non-evaluative concepts - for example, that justification can be explained in terms of something like reliability. They deny a special normative realm of language that is theoretically different from the kinds of concepts used in factual scientific discourse. Non-naturalists deny this and hold to the essential difference between normative and the factual: The former can never be derived from or constituted by the latter. So internalists tend to think of reason and rationality as non-explicable in natural, descriptive terms, whereas, Externalists think such an explanation is possible.

Although the reason, . . . to what we think to be the truth. The sceptic uses an argumentive strategy to show the alternatives strategies that we do not genuinely have knowledge and we should therefore suspend judgement. But, unlike the sceptics, many other philosophers maintain that more than one of the alternatives are acceptable and can constitute genuine knowledge. However, it seems dubitable to have invoked hypothetical sceptics in their work to explore the nature of knowledge. These philosophers did no doubt that we have knowledge, but thought that by testing knowledge as severely as one can, one gets clearer about what counts as knowledge and greater insight results. Hence there are underlying differences in what counts as knowledge for the sceptic and other philosophical appearances. As traditional epistemology has been occupied with dissassociative kinds of debate that led to a dogmatism. Various types of beliefs were proposed as candidates for sceptic-proof knowledge, for example, those beliefs that are immediately derive by many as immune to doubt. Nevertheless, that they all had in common was that empirical knowledge began with the data of the senses, that this was safe from scepticism and that a further superstructure of knowledge was to be built on this firm basis.

It might well be observed that this reply to scepticism fares better as a justification for believing in the existence of external objects, than as a justification of the views we have about their nature. It is incredible that nothing independent of us is responsible for the manifest patterns displayed by our sense-data, but granting this leaves open many possibilities about the nature of the hypnotized external reality. Direct realists often make much of the apparent advantage that their view has in the question of the nature of the external world. The fact of the matter is, though, that it is much harder to arrive at tenable views about the nature of external reality than it is to defend the view that there is an external reality of some kind or other. The history of human thought about the nature of the external world is littered with what are now seen (with the benefit of hindsight) to be egregious errors - the four element theory, phlogiston, the crystal spheres, vitalism, and so on. It can hardly be an objection to a theory that makes the question of the nature of external reality much harder than the question of its existence.

The way we talk about sensory experience certainly suggests an act/object view. When something looks thus and so in the phenomenological sense, we naturally describe the nature of our sensory experience by saying that we are acquainted with a thus ans so ‘given’. But suppose that this is a misleading grammatical appearance, engendered by the linguistic propriety of forming complete, putatively referring expressions like ‘the bent shape on my visual field’, and that there is no more a bent shape in existence for the representative realist to contend to be a mental sense-data, than there is a bad limp in existence when someone has, as we say, a bad limp. When someone has a bad limo, they limp badly, similarly, according to adverbial theorist, when, as we naturally put it, I am aware of a bent shape, we would better express the way things are by saying that I sense bent shape-ly. When the act/object theorist analyses as a feature of the object which gives the nature of the sensory experience, the adverbial theorist analyses as a mode of sense which gives the nature of the sensory experience. (The decision between the act/object and adverbial theories is a hard one.)

In the best-known form the adverbial theory of experience proposes that the grammatical object of a statement attributing an experience to someone be analysed as an adverb. For example,

(1) Rod is experiencing a pink square

is rewritten as,

Rod is experiencing (pink square)-ly

This is presented as an alterative to the act/object analysis, according to which the truth of a statement like (1) requires the existence of an object of experience corresponding to its grammatical object. A commitment to the explicit adverbialization of statements of experience is not, however, essential to adverbialism. The core of the theory consists, rather, in the denial of objects of experience, as opposed to objects of perception, and coupled with the view that the role of the grammatical object is a statement of experience is to characterize more fully the sort of experience which is being attributed to the subject. The claim, then, is that the grammatical object is functioning as a modifier, and, in particular, as a modifier of a verb. If this is so, it is perhaps appropriate to regard it as a special kind of adverb at the semantic level.

Nonetheless, in the arranging accordance to the act/object analysis of experience, every experience with content involves an object of experience to which the subject is related by an act of awareness in the event of experiencing that object. Such as these experiences are, it is, nonetheless. The experiences are supposed to be whatever it is that they represent. Act, object theorist may differ on the nature of objects of experience, which h have been treated as properties. However, and, more commonly, private mental objects in which may not exist have any form of being, and, with sensory qualifies the experiencing imagination may walk upon the corpses of times’ generations, but this has also been used as a unique application to is mosaic structure in its terms for objects of sensory experience or the equivalence of the imaginations striving from the mental act as presented by the object and forwarded by and through the imaginistic thoughts that are released of a vexing imagination. Finally, in the terms of representative realism, objects of perception of which we are ‘directly aware’, as the plexuity in the abstract objects of perception exist if objects of experience.

As the aforementioned, traditionally representative realism is allied with the act/object theory. But we can approach the debate or by rhetorical discourse as meant within dialectic awareness, for which representative realism and direct realism are achieved by the mental act in abdication to some notion of regard or perhaps, happiness, all of which the prompted excitations of the notion expels or extractions of information processing. Mackie (1976( argues that Locke (1632-1704) can be read as approaching the debate ion television. My senses, in particular my eyes and ears, ‘tell’ me that Carlton is winning. What makes this possible is the existence of a long and complex causal chain of electro-magnetic radiation from the game through the television cameras, various cables between my eyes and the television screen. Each stage of this process carries information about preceding stages in the sense that the way things are at a given stage depends on the way things are at preceding stages. Otherwise the information would not be transferred from the game to my brain. There needs to be a systematic covariance between the state of my brain and the state unless it obtains between intermediate members of the long causal chain. For instance, if the state of my retina did not systematically remit or consign with the state of the television screen before me, my optic nerve would have, so to speak, nothing to go on to tell my brain about the screen, and so in turn would have nothing to go on to tell my brain about the game. There is no information at a distance’.

A few of the stages in this transmission of information between game and brain are perceptually aware of them. Much of what happens between brain and match I am quite ignorant about, some of what happens I know about from books, but some of what happens I am perceptually aware of the images on the scree. I am also perceptually aware of the game. Otherwise I could not be said to watch the game on television. Now my perceptual awareness of the match depends on my perceptual awareness of the screen. The former goes by means of the latter. In saying this I am not saying that I go through some sort of internal monologue like ‘Such and such images on the screen are moving thus and thus. Therefore, Carlton is attacking the goal’. Indeed, if you suddenly covered the screen with a cloth and asked me (1) to report on the images, and (2) to report in the game. I might well find it easier to report on the game than on the images. But that does not mean that my awareness of the game does not go by way of my awareness of the images on the screen. The shows that I am more interested in the game than in the screen, and so am storing beliefs about it in preference e to beliefs about the screen.

We can now see how elucidated representative realism independently of the debate between act/object and adverbial theorists about sensory experience. Our initial statement of representative realism talked of the information acquired in perceiving an object being most immediately about the perceptual experience caused in us by the object, and only derivatively about objects itself, in the act/object, sense-data approach, what is held to make that true is that the fact that what we are immediately aware of it’s mental sense-datum. But instead, representative realists can put their view this way: Just as awareness of the match game by means of awareness of the screen, so awareness of the screen foes by way of awareness of experience., and in general when subjects perceive objects, their perceptual awareness always does by means of the awareness of experience.

Why believe such a view? Because of the point that was inferred earlier: The worldly provision by our senses is so very different from any picture provided by modern science. It is so different in fact that it is hard to grasp what might be meant by insisting that we are in epistemologically direct contact with the world.

An argument from illusion is usually intended to establish that certain familia r facts about illusion disprove the theory of perception and called naïve or direct realism. There are,. However, many different versions of the argument which must be distinguished carefully. Some of these premisses (the nature of the appeal to illusion):Others centre on the interpretation of the conclusion (the kind of direct realism under attack). In distinguishing important differences in the versions of direct realism. One might be taken to be vulnerable to familiar facts about the possibility of perceptual illusion.

A crude statement of direct realism would concede to the connection with perception, such that we sometimes directly perceive physical objects and their properties: We do not always perceive physical objects by perceiving something else, e.g., a sense-data. There are, however, difficulties with this formulation of the view. For one thing a great many philosophers who are not direct realists would admit that it is a mistake to describe people as actually perceiving something other than a physical object. In particular, such philosophers might admit, we should never say that we perceive sense-data. To talk that way would be to suppose that we should model our understanding of our relationship to sense-data on our understanding of the ordinary use of perceptual verbs as they describe our relation to the physical world, and that is the last thing paradigm sense-data theorists had better want. At least, many of the philosophers who objected to direct realism would prefer to express what they were objecting to in terms of a technical and philosophical controversial concept such as acquaintance. Using such a notion we could define direct realism this way: In veridical experience we are directly acquainted with parts, e.g., surfaces, or constituents of physical objects. A less cautious version of the view might drop the reference to veridical experience and claim simply that in all parts or constituents of physical objects.

We know things by experiencing them, and knowledge of acquaintance. (Russell changed the preposition to ’by’) is epistemically prior to and has a relatively higher degree of epistemic justification than knowledge about things. Indeed, sensation has ‘the one great value of trueness or freedom from mistake’.

A thought (using that term broadly, to mean any mental state) constituting knowledge of acquaintance with thing is more or less causally proximate to sensations caused by that thing is more or less distant causal y, being separated from the thing and experience of it by processes of attention and inference. At the limit, if a thought is maximally of the acquaintance type, it is the first mental state occurring in a object to which the thought refers, i.e., it is a sensation. The things we have knowledge of acquaintance e include ordinary objects in the external world, such as the Sun.

Grote contrasted the imaginistic thoughts involved in knowledge of acquaintance with things, with the judgements involved in knowledge about things, suggesting that the latter but not the former are contentful mental states. Elsewhere, however, he suggested that every thought capable of constituting knowledge of or about a thing involves a form, idea, or what we might call conceptual propositional content, referring the thought to its object. Whether contentful or not, thoughts constituting knowledge of acquaintance with a thing as r relatively indistinct, although this indistinctness does not imply incommunicability. Yet, thoughts constituting knowledge about a thing are relatively distinct, as a result of ‘the application of notice or attention’ to the ‘confusion or chaos’ of sensation. Grote did not have an explicit theory of reference e, the relation by which a thought of or about a specific thing. Nor did he explain how thoughts can be more or less indistinct.

Helmholtz (1821-94) held unequivocally that all thoughts capable of constituting knowledge, whether ‘knowledge e which has to do with notions’ or ‘mere familiarity with phenomena’ are judgements or, we may say, have conceptual propositional contents. Where Grote saw a difference e between distinct and indistinct thoughts. Helmholtz found a difference between precise judgements which are expressible in words and equally precise judgement which, in principle, are not expressible in words, and so are not communicable.

James (1842-1910), however, made a genuine advance over Grote and Helmholtz by analysing the reference relations holding between a thought and the specific thing of or about which it is knowledge. In fact, he gave two different analyses. On both analyses, a thought constituting knowledge about a thing refers to and is knowledge about ‘a reality, whenever it actually or potentially terminates in’ a thought constituting knowledge of acquaintance with that thing. The two analyses differ in their treatments of knowledge of acquaintance. On James’s first analyses, reference in both sorts of knowledge is mediated by causal chains. A thought constituting pure knowledge of acquaintance with a thing refers to and is knowledge of ‘whatever reality it directly or indirectly operates on and resembles’. The concepts of a thought ‘operating in’ a thing or ‘terminating in’ another thought are causal, but where Grote found chains of efficient causation connecting thought and referent. James found teleology and final causes. On James’s later analysis, the reference involved in knowledge of acquainting e with a thing is direct. A thought constituting knowledge of acquaintance with a thing as a constituent and the thing and the experience of it are identical.

James further agreed with Grote that pure knowledge of acquaintance with things, eg., sensory experience, is epistemically prior to knowledge about things. While the epistemic justification involved in knowledge about all thoughts about things are fallible and their justification is augmented by their mutual coherence. James was unclear about the precise epistemic status of knowledge of acquaintance. At times, thoughts constituting pure knowledge of acquaintance are said to posses ‘absolute veritableness’ and ‘the maximal conceivable truth’, suggesting that such thoughts are genuinely cognitive and that they provide an infallible epistemic foundation. At other times, such thoughts are said not to bear truth-values, suggesting that ‘knowledge’ of acquaintance is not genuine knowledge at all, but only a non-cognitive necessary condition of genuine knowledge, that is to say, the knowledge about things.

What is more, that, Russell (1872-1970) agreed with James that knowledge of things by acquaintance ‘is essentially simpler than any knowledge of truths, and logically independent of knowledge of truth’. That the mental states involved when one is acquainted with things do not have propositional contents. Russell’s reasons were to seem as having been similar to James’s. Conceptually unmediated reference to particulars is necessary for understanding any proposition mentioning a particular and, if scepticism about the external world is to be avoided, some particulars must be directly perceived. Russell vacillated about whether or not the absence of propositional content renders knowledge by acquaintance incommunicable.

Russell agreed with James that different accounts should be given of reference as it occurs in knowledge by acquaintance and in knowledge about things, and that in the former case reference is direct. But, Russell objected on the number of grounds to James’s causal account of the indirect reference involved in knowledge about things. Russell gave a descriptional rather than a causal analysis of that sort of reference. A thought is about a thing when the content of the thought involves a definite description uniquely satisfied by the thing referred to. Yet, he preferred to speak of knowledge of things by description, than of knowledge about things.

Russell advanced beyond Grote and James by explaining how thoughts can be more or less articulate and explicit. If one is acquainted with a complex thing without being aware of or acquainted with its complexity, the knowledge one has by acquaintance e with that thing is vague and inexplicit. Reflection and analysis can lead to distinguish constituent parts of the object of acquaintance and to obtain progressively more distinct, explicit, and complete knowledge about it.

Because one can interpret the reflation of acquaintance or awareness as one that is not epistemic, i.e., not a kind of propositional knowledge, it is important to distinguish the views read as ontological theses from a view one might call epistemological direct realism: In perception we are, on, at least some occasions, non-inferentially justified in believing a proposition asserting the existence e of a physical object. A view about what the object of perceptions are. Direct realism is a type of realism, since it is assumed that these objects exist independently of any mind that might perceive them: And so it thereby rules out all forms of idealism and phenomenalism, which holds that there are no such independently existing objects. Its being a ‘direct realism rules out those views’ defended under the rubic of ‘critical realism’, of ‘representative realism’, in which there is some non-physical intermediary - usually called a ‘sense-data’ or a ‘sense impression’ - that must first be perceived or experienced in order to perceive the object that exists independently of this perception. According to critical realists, such an intermediary need not be perceived ‘first’ in a temporal sense, but it is a necessary ingredient which suggests to the perceiver an external reality, or which offers the occasion on which to infer the existence of such a reality. Direct realism, however, denies the need for any recourse to mental go-between in order to explain our perception of the physical world.

This reply on the part of the direct realist does not, of course, serve to refute the global sceptic, who claims that, since our perceptual experience could be just as it is without there being any real properties at all, we have no knowledge of any such properties. But no view of perception alone is sufficient to refute such global scepticism. For such a refutation we must go beyond a theory that claims how best to explain our perception of physical objects, and defend a theory that best explains how we obtain knowledge of the world.

All is the equivalent for an external world, as philosophers have used the term, is not some distant planet external to Earth. Nor is the external world, strictly speaking, a world. Rather, the external world consists of all those objects and events which exist external to perceiver. So the table across the room is part of the external world, and so is the room in part of the external world, and so is its brown colour and roughly rectangular shape. Similarly, if the table falls apart when a heavy object is placed on it, the event of its disintegration is a pat of the external world.

One object external to and distinct from any given perceiver is any other perceiver. So, relative to one perceiver, every other perceiver is a part of the external world. However, another way of understanding the external world results if we think of the objects and events external to and distinct from every perceiver. So conceived the set of all perceivers makes up a vast community, with all of the objects and events external to that community making up the external world. Thus, our primary considerations are in the concern from which we will suppose that perceiver are entities which occupy physical space, if only because they are partly composed of items which take up physical space.

What, then, is the problem of the external world. Certainly it is not whether there is an external world, this much is taken for granted. Instead, the problem is an epistemological one which, in rough approximation, can be formulated by asking whether and if so how a person gains of the external world. So understood, the problem seems to admit of an easy solution. Thee is knowledge of the external world which persons acquire primarily by perceiving objects and events which make up the external world.

However, many philosophers have found this easy solution problematic. Nonetheless, the very statement of ‘the problem of the external world itself’ will be altered once we consider the main thesis against the easy solution.

One way in which the easy solution has been further articulated is in terms of epistemological direct realism. This theory is the realist insofar as it claims that objects and events in the external world, along with many of their various features, exist independently of and are generally unaffected by perceivers and acts of perception in which they engage. And this theory is epistemologically direct since it also claims that in perception people often, and typically acquire immediate non-inferential knowledge of objects and events in the external world. It is on this latter point that it is thought to face serious problems.

The main reason for this is that knowledge of objects in the external world seems to be dependent on some other knowledge, and so would not qualify as immediate and non-inferentially is claimed that I do not gain immediate non-inferential perceptual knowledge that thee is a brown and rectangular table before me, because I would know such a proposition unless I knew that something then appeared brown and rectangular. Hence, knowledge of the table is dependent upon knowledge of how it appears. Alternately expressed, if there is knowledge of the table at all, it is indirect knowledge, secured only if the proposition about the table may be inferred from propositions about appearances. If so, epistemological direct realism is false’

This argument suggests a new way of formulating the problem of the external world:

Problem of the external world: Can firstly, have knowledge of propositions about objects and events in the external world based on or upon propositions which describe how the external world appears, i.e., upon appearances?

Unlike our original formulation of the problem of the external world, this formulation does not admit of an easy solution. Instead, it has seemed to many philosophers that it admits of no solution at all, so that scepticism regarding the eternal world is only remaining alternative.

This theory is realist in just the way described earlier, but it adds, secondly, that objects and events in the external world are typically directly perceived, as are many of their features such as their colour, shapes, and textures.

Often perceptual direct realism is developed further by simply adding epistemological direct realism to it. Such an addition is supported by claiming that direct perception of objects in the external world provides us with immediate non-referential knowledge of such objects. Seen in this way, perceptual direct realism is supposed to support epistemological direct realism, strictly speaking they are independent doctrines. One might consistently, perhaps even plausibly, hold one without also accepting the other.

Direct perception is that perception which is not dependent on some other perception. The main opposition to the claim that we directly perceive external objects comes from direct or representative realism. That theory holds that whenever an object in the external world is perceived, some other object is also perceived, namely a sensum - a phenomenal entity of some sort. Further, one would not perceive the external object if one would not perceive the external object if one were to fail to receive the sensum. In this sense the sensum is a perceived intermediary, and the perception of the external object is dependent on the perception of the sensum. For such a theory, perception of the sensum is direct, since it is not dependent on some other perception, while perception on the external object is indirect. More generally, for the indirect t realism., all directly perceived entities are sensum. On the other hand, those who accept perceptual direct realism claim that perception of objects in the external world is typically direct, since that perception is not dependent on some perceived intermediaries such as sensum.

It has often been supposed, however, that the argument from illusion suffices to refute all forms of perceptual direct realism. The argument from illusion is actually a family of different arguments rather than one argument. Perhaps the most familiar argument in this family begins by noting that objects appear differently to different observers, and even to the same observers on different occasions or in different circumstances. For example, a round dish may appear round to a person viewing it from directly above and elliptical to another viewing it from one side. As one changes position the dish will appear to have still different shapes, more and more elliptical in some cases, closer and closer to round in others . In each such case, it is argued, the observer directly sees an entity with that apparent shape. Thus, when the dish appears elliptical, the observer is said to see directly something which is elliptical. Certainly this elliptical entity is not the top surface of the dish, since that is round. This elliptical entity, a sensum, is thought to be wholly distinct from the dish.

In seeing the dish from straight above it appears round and it might be thought that then directly sees the dish rather than a sensum. But here too, it relatively sett in: The dish will appear different in size as one is placed at different distances from the dish. So even if in all of these cases the dish appears round, it will; also appear to have many different diameters. Hence, in these cases as well, the observer is said to directly see some sensum, and not the dish.

This argument concerning the dish can be generalized in two ways. First, more or less the same argument can be mounted for all other cases of seeing and across the full range of sensible qualities - textures and colours in addition to shapes and sizes. Second, one can utilize related relativity arguments for other sense modalities. With the argument thus completed, one will have reached the conclusion that all cases of non-hallucinatory perception, the observer directly perceives a sensum, and not an external physical object. Presumably in cases of hallucination a related result holds, so that one reaches the fully general result that in all cases of perceptual experience, what is directly perceived is a sensum or group of sensa, and not an external physical object, perceptual direct realism, therefore, is deemed false.

Yet, even if perceptual direct realism is refuted, this by itself does not generate a problem of the external world. We need to add that if no person ever directly perceives an external physical object, then no person ever gains immediate non-inferential knowledge of such objects. Armed with this additional premise, we can conclude that if there is knowledge of external objects, it is indirect and based upon immediate knowledge of sensa. We can then formulate the problem of the external world in another way:

Problems of the external world: can, secondly, have knowledge of propositions about objects and events in the external world based upon propositions about directly perceived sensa?

It is worth nothing the differences between the problems of the external world as expounded upon its first premise and the secondly proposing comments as listed of the problems of the external world, we may, perhaps, that we have knowledge of the external world only if propositions about objects and events in the external world that are inferrable from propositions about appearances.

Some philosophers have thought that if analytical phenomenalism were true, the situational causalities would be different. Analytic phenomenalism is the doctrine that every proposition about objects and events in the external world is fully analysable into, and thus is equivalent in meaning to, a group of inferrable propositions . The numbers of inferrable propositions making up the analysis in any single propositioned object and or event in the external world would likely be enormous, perhaps, indefinitely many. Nevertheless, analytic phenomenalism might be of help in solving the perceptual direct realism of which the required deductions propositioned about objects and or events in the external world from those that are inferrable from prepositions about appearances. For, given analytical phenomenalism there are indefinite many in the inferrable propositions about appearances in the analysis of each proposition taken about objects and or events in the external world is apt to be inductive, even granting the truth of a analytical phenomenalism. Moreover, most of the inferrable propositions about appearances into which we might hope to analyse of the external world, then we have knowledge of the external world only if propositions about objects and events in the external world would be complex subjunctive conditionals such as that expressed by ‘If I were to seem to see something red, round and spherical, and if I were to seem to try to taste what I seem to see, then most likely I would seem to taste something sweet and slightly tart’. But propositionally inferrable appearances of this complex sort will not typically be immediately known. And thus knowledge of propositional objects and or event of the external world will not generally be based on or upon immediate knowledge of such propositionally making appearances.

Consider upon the appearances expressed by ‘I seem to see something red, round, and spherical’ and ‘I seem to taste something sweet and slightly tart’. To infer cogently from these propositions to that expressed by ‘There is an apple before me’ we need additional information, such as that expressed by ‘Apples generally cause visual appearance of redness, roundness, and spherical shape and gustatory appearance of sweetness and tartness’. With this additional information., the inference is a good on e, and it is likely to be true that there is an apple there relative to those premiered. The cogency of the inference, however, depends squarely on the additional premise, relative only to the stated inferrability placed upon appearances, it is not highly probable that thee is an apple there.

Moreover, there is good reason to think that analytic phenomenalism is false. For each proposed translation of an object and eventfully external world into the inferrable propositions about appearances. Mainly enumerative induction is of no help in this regard, for that is an inference from premisses about observed objects in a certain set-class having some properties ‘F’ and ‘G’ to unobserved objects in the same set-class having properties ‘F’ and ‘G’, to unobserved objects in the same set-class properties ‘F’ and ‘G’. If satisfactory, then we have knowledge of the external world if propositions are inferrable from propositions about appearances, however, concerned considerations drawn upon appearances while objects and or events of the external world concern for externalities of objects and interactive categories in events, are. So, the most likely inductive inference to consider is a causal one: We infer from certain effects, described by promotional appearances to their likely causes, described by external objects and or event that profited emanation in the concerning propositional state in that they occur. But, here, too, the inference is apt to prove problematic. But in evaluating the claim that inference constitutes a legitimate and independent argument from, one must explore the question of whether it is a contingent fact that, at least, most phenomena have explanations and that be so, that a given criterion, simplicity, were usually the correct explanation, it is difficult to avoid the conclusion that if this is true it would be an empirical fact about our selves in discovery of an reference to the best explanation.

Defenders of direct realism have sometimes appealed to an inference to the best explanation to justify prepositions about objects and or events in the external world, we might say that the best explanation of the appearances is that they are caused by external objects. However, even if this is true, as no doubt it is, it is unclear how establishing this general hypophysis helps justify specific ordination upon the proposition about objects and or event in the external world, such as that these particular appearances of a proposition whose inferrable properties about appearances caused by the red apple.

The point here is a general one: Cogent inductive inference from the inferrable proposition about appearances to propositions about objects and or events in the external world are available only with some added premiss expressing the requisite causal relation, or perhaps some other premiss describing some other sort of correlation between appearances and external objects. So there is no reason to think that indirect knowledge secured if the prepositions about its outstanding objectivity from realistic appearances, if so, epistemological direct realism must be denied. And since deductive and inductive inferences from appearance to objects and or events in the external world are propositions which seem to exhaust the options, no solution to its argument that sustains us of having knowledge of propositions about objects and events in the external world based on or upon propositions which describe the external world as it appears at which point that is at hand. So unless there is some solution to this, it would appear that scepticism concerning knowledge of the external world would be the most reasonable position to take

If the argument leading to some additional premise as might conclude that if there is knowledge of external objects if is directly and based on or upon the immediate knowledge of sensa, such that having knowledge of propositions about objects and or events in the external world based on or upon propositions about directly perceived sensa? Broadly speaking, there are two alternatives to both the perceptual indirect realism, and, of course, perceptual phenomenalism. In contrast to indirect t realism, and perceptual phenomenalism is that perceptual phenomenalism rejects realism outright and holds instead that (1) physical objects are collections of sensa, (2) in all cases of perception, at least one sensa is directly perceived, and, (3) to perceive a physical object one directly perceives some of the sensa which are constituents of the collection making up that object.

Proponents of each of these position try to solve the conditions not engendered to the species of additional persons ever of directly perceiving an external physical object, then no person ever gains immediate non-referential knowledge of such objects in different ways, in fact, if any the better able to solve this additional premise, that we would conclude that if there is knowledge of external objects than related doctrines for which time are aforementioned. The answer has seemed to most philosophers to be ‘no’, for in general indirect realists and phenomenalists have strategies we have already considered and rejected.