p Already in antiquity, the view is formed that the knowledge of an object results from a causal impact of the 22 object on the subject. True, that action is interpreted in an original way: an “image” of the object is separated or “emanates” from it and floats in the space between the object and the subject; getting into the subject, the image assumes the quality of knowledge.

p The philosophy of the New Times lends a different shape to a basically similar conception of the mechanism of origin of knowledge. In terms of the ideas of classical mechanics, which had taken shape by that time, only material physical bodies can affect one another, the only qualities immediately inherent in the bodies being density, extension, and form. There can be no question of “ emanation” of “images”. Bodies can leave only material traces of impact in each other. The result of the physical impact on the sense organs (whether it be direct impact, as in the case of tactile impressions, or a mediated one, as in the case of vision) is sense perception—the primary and basic kind of knowledge. All other kinds or types of knowledge are, in one way or another, derivative from perception. Therefore to discover its mechanism would in fact mean to discover the essence of knowledge, of the cognitive relation in general.

p Here is how one of the classical adherents of such conceptions, the English philosopher John Locke, reasoned: "... Simple ideas [that was the term Locke used for what is now called sense perception —V. L. ] are not fictions of our fancies, but the natural and regular productions of things without us, really operating upon us; and so carry with them all the conformity which is intended, or which our state requires; for they represent to us things under those appearances which they are fitted to produce in us; whereby we are enabled to distinguish the sorts of particular substances, to discern the states they are in, and so to take them for our necessities, and apply them to our uses. And this conformity between our simple ideas and the existence of things is sufficient for real knowledge.”^^1^^

p It is by the specific formations arising in the subject himself, by the “ideas” or sense perceptions, that man judges of the really existing objects. The relation of the system of interconnected perceptions to the real objects reminds one of the relation of a map to the actual landscape. The map is not the terrain itself. At the same time a man who can read the map will clearly understand the interrelations of the real objects in the area described by the map.

p The argument seems clear and logical. The development of modern neurophysiology indeed describes a great many dependences characterising causal chains that form in the external objects, then pass through man’s senses and 23 further to the brain. These descriptions take into account the laws of diffusion, reflection and diffraction of light in the case of vision, the specificity of the spread of sound oscillation in the case of hearing, the structure of the retina, the laws of excitation of the conductor nerves, etc. It is important to emphasise that modern studies have established that the cortex plays an exceptionally important role in the process of perception. Where a certain centre (visual, auditory, etc.) is damaged, the corresponding perception process is disrupted.

p Neurophysiological studies undoubtedly have an immense significance for disclosing the material mechanisms of perception, and a great deal will have to be done in this direction. The question, however, is whether these studies by themselves are sufficient to understand perception as a special kind of knowledge, and whether the neurophysiological data can be interpreted in the theory of perception which we have briefly outlined here and which has been termed in philosophy representationism.

p Let us note that in representationist terms, not all that exists in perception corresponds to the features of actually existing objects. Since the natural sciences, and in the first place physics, do not use the concepts of colour, taste, smell, etc., the corresponding properties of perception, the upholders of this view believe, should be regarded as emerging through the object influencing the subject rather than inherent in the actually existing objects (characterised by the concepts of extension, density, quantity, form, motion, etc.). Thus the theory of the so-called primary and secondary qualities is formulated, a theory that was presented in clear form by Locke and still has some supporters. The “primary” qualities of our perceptions (perception of spatial relations between objects, their size, etc.) reproduce more or less precisely the real properties of the objects themselves. As for the “secondary” qualities, they do not reproduce the properties of objects existing outside us, although they have objective causes. The “secondary” qualities, though not fully subjective and illusory, are thus more subjective than the “primary” ones.

p Let us now consider the logic of the representationist conception. This will enable us to see its weak points.^^2^^

p (1) Let us begin with the fact that the very division into “primary” and “secondary” qualities is extremely shaky. It is true, of course, that the natural sciences do not use such concepts as colour, taste, smell, etc. (although these sciences might, of course, use concepts correlative with those of colour, taste, and smell—e.g., the concept of electromagnetic wave length). Neither does such a science 24 as neurophysiology resort to the concepts of colour and taste, explaining the mechanism of perception through description of various spatial arrangements of the conductor nerves and brain centres and also studying the frequency of propagation of excitation along the nerve paths. The so-called secondary qualities do not appear as objects of neurophysiological analysis, for they cannot in principle be introduced into the system of physical interaction. But the question arises then, where do they emerge and in what “space” do they exist? We can no longer be satisfied with the answer that they emerge "in the process" of the object operating on the subject, for analysis of this process in terms of interaction between natural bodies does not make use of a concept pertaining to these “qualities”.

p The assertion also appears unconvincing that the “ primary” qualities, as distinct from the “secondary” ones, reproduce more or less precisely the properties of real objects. The subjective element in the perception of colour, in gustatory senses and others is rather prominent. But the element of subjectiveness is always present in the perception of spatial forms and relations of actual objects, too. In some cases this subjectiveness is so great that it necessarily produces various illusions of perception that have been studied in detail in modern psychology. In everyday life, however, it is correctly believed that perception of spatial forms of things is on the whole objective. Why then is subjectiveness ascribed to the perception of sound, colour, smell, etc.? It is correct that the conceptual picture of the world drawn by the natural sciences does not include colours, sounds, or smells. But it does not include many of the spatio-temporal interrelations fixed in material bodies which from the standpoint of pre-scientific "common sense" are necessary attributes of the objective, real world. If we should accept that only those characteristics of reality actually exist which are expressed in the concepts of the modern natural-scientific theories, we arrive at the conclusion that not only properties corresponding to “ secondary” qualities are non-existent, but so are the objective correlates of the “primary” qualities, for that which we perceive as things more or less distinctly localised in space and time is, in terms of modern physics, merely a complex agglomeration of processes on the quantum mechanical level. In this case, our ordinary notions of space, time, and localisation of objects no longer work. The ordinary perception of external objects including both “secondary” and “primary” qualities will here appear as something that does not accord with their nature, as a consequence of the specific structure of our sense organs and of the fact that 25 our body size is on the macroscale.

p But doesn’t this assumption take us too far along the path of subjectivism?

p Let us point out finally that the other assumption on which the division of perceived qualities into “primary” and “secondary” is based is open to criticism. We mean ascribing some fundamental affinity between the result of impact of the “primary” qualities of the object on the sense organs and the qualities themselves. As shown by neurophysiological research, the processes that take place in the nervous system at the moment of perception have, as a rule, no external similarity to the phenomena that are the objects of perception.

p (2) It follows from the "causal theory" of perception that the subject is directly concerned with the “traces” of the object’s impact on the perceiving apparatus rather than with the object itself. The subject "transports outside”, as it were, the features or “qualities” of these “traces”, “ projecting” them onto the real object and ascribing them to the object itself, although not all of them are actually inherent in the latter.

p It is not clear, however, just why the subject necessarily ascribes to the object qualities that are not characteristic of it, and how it does so. The mechanism of projection is impossible to understand in terms of action of one physical system on another.

p (3) Then there is this puzzle: how can the subject “read”, i.e., perceive the “imprints” or “traces” of the action of the object on his perceiving apparatus?

p Indeed, according to the given conception, all perception is necessarily mediated by the sense organs and the nervous apparatus. What are the sense organs that can perceive the “imprints” given in the apparatus itself that realises the process of perception? Even if we assume that such special "sense organs" do exist, that is no solution of the problem, for in these "sense organs" there must be some new “imprints” which again have to be “read” by someone, etc. And who is that “someone” reading the imprints? The subject? But the basic premise of this conception is that the subject is a physical body, a natural material system, which cannot exist somewhere in its own nervous apparatus reading imprints in its own brain.

p The only way out is to recognise that the process of perception of “imprints” in the perceiving system is fundamentally different from the perception of external objects and that the former process is realised directly, without sense organs or “reading” the corresponding traces. However, that would mean rejecting the view that the origin of 26 sense perception as a special kind of knowledge can he fully and exhaustively interpreted in terms of action of one physical system upon another.

p (4) Consistent adherence to this conception inevitably entails subjectivistic conclusions contradicting the materialist theory of reflection. Here is one of them. The “ causal” theory of perception postulates that direct perception is characteristic of processes in the subject’s receiving apparatus and can be correlated with the real object in a very mediated manner. The actual processes during perception may be disclosed by studying the work of analysers and the brain and nerve structures. If we follow the logic of this conception, we shall have to accept that the physiologist studying the work of the brain does not, in actual fact, deal directly with that brain but only with his own, for any object is accessible to the scientist only through the “imprints” in his own brain, which “symbolise” external reality rather approximately, being similar to that reality only in some respects. Bertrand Russell, an adherent of the “causal” theory of perception, draws this conclusion, insisting that it is a mistake to assume "that a man can see matter. Not even the ablest physiologist can perform this feat. His percept when he looks at a brain is an event in his own mind, and has only a causal connection with the brain that he fancies he is seeing.”^^3^^

p Following the path of subjectivism, Russell, unlike Locke and other metaphysical materialists, includes the "causal theory" of perception within the framework of a subjective idealistic philosophical conception. That which was a concession to subjectivism in metaphysical materialists, becomes the nucleus of Russell’s epistemology.

p (5) Let us finally point out an essential circumstance that is hard to explain, if one regards perception as simple causal action of one physical system on another. We refer to the fact that perception always assumes realisation of percepts and their inclusion (in the process of perception itself) in some category of objects, which is expressed in understanding the object perceived.Understanding means a certain activity of the subject, manifested, among other things, in different objective interpretations and perceptions of one and the same action of the object on the subject’s receptive apparatus. The objective interpretation of reality takes place in the framework of a certain system of objective “standards”. Perception thus has definite normative features.

p Generally speaking, it is those features of perception which have to do with its conscious and normative character that are least amenable to interpretation in terms of 27 causal impact of one physical system upon another. The need to view perception as a special structure, a phenomenon of consciousness rather than a simple “imprint”, has come up in other cases, e.g., when we spoke of the problem of localising the sensual image, explaining the mechanism of “projection”, etc.. Most supporters of the “causal” theory of perception recognise, in one way or another, that the chains of natural causation in the subject’s receptive apparatus result in the emergence of a specific phenomenon that cannot be directly understood and explained in the concepts of mechanics, physics, chemistry, and other natural sciences—the phenomenon of sensual image consciously realised by the subject (that is Russell!s position). This recognition, however, means in fact a rejection of the interpretation of the cognitive relation as merely a special type of connection between two physical systems.

p Let us stress that critique of the “causal” conception of perception does not at all mean rejecting the idea that the subject is in some respects indeed a complex natural system, that the object does indeed act on the sense organs of the cognizing subject, and that cognition is in general impossible without this action.

Then again, it is impossible to ignore the enormous mass of material accumulated by neurophysiology. The task lies, apparently, in a philosophical-theoretical interpretation of that material.