p The view that the true properties of reality are grasped as a result of direct impact of the object on the subject, or in the form of some kind of “fusion” of the subject and the object, and that the distortions, errors, and illusions are wholly explained by the fact that the subject is not passive enough in following the "objective givenness”, introducing something of himself in the cognitive process (either of his physical and physiological nature or of the activeness of consciousness), was deeply rooted in preMarxian epistemology. It was of course a long established fact that perception may be deceptive, that it can lead to error in understanding the meaning of certain objective situations, yet it was never doubted that from the practical viewpoint it in most cases yielded correct knowledge. At the same time attaining truth through abstract thinking was in one way or another linked up in classical philosophy with the act of direct, passive grasping (Plato’s " intelligent vision" of ideas, intellectual intuition of the rationalist philosophers of the 17th and 18th centuries; Husserl’s direct "insight into the essences”, etc.), that is, it 128 was understood on the analogy of passively interpreted perception. Thus the question of the subject’s activeness and passiveness in the cognitive process was closely linked with one of the focal philosophical problems widely debated since antiquity-^he problem of the relation between reality and appearance or illusion.

p The modern psychology of perception provides a wealth of material to support the philosophically important proposition that the results (“traces”) of the impact of the external object on the sense organs are not at all enough to distinguish between reality and illusion, for, as we have said already, different configurations of these traces may correspond to most diverse real objects. The singling out of real objects from the sensory information through imposing certain object-hypotheses on the latter is ensured not only by the subject’s cognitive activity but also by the object-hypotheses themselves having been tested in practical activity (collective or individual) and indicating those aspects of the real objects which are essential precisely for that activity. When the subject encounters some objects previously unknown to him in his practical activity, or familiar objects in unusual situations, objects viewed from unusual angles, an illusion arises: one perceives something that does not actually exist. (We ignore here those perception distortions which result from sensory receptors being tired or from their adaptation to prolonged or intense stimulation.) Although in this case sensory information coming from the object may be completely undistorted and can be fully taken into account, it may prove entirely insufficient for eliminating the illusion and establishing the real object. In other words, illusion is in this case by no means the result of the subject’s activity but merely a consequence of the activity being inadequate to the objective situation.

p Adalbert Ames, an American psychologist, has performed the following experiment. Three peepholes are made in a screen through which one can look with one eye at each of the three objects displayed in the distance. Each of them is perceived under the given conditions as a chair. But when we look at the three objects from another angle, we discover that only one of the objects is indeed a chair. The other two are extremely strange objects which can nevertheless produce from a certain angle the same projection on the retina as a real chair. (One of the objects is not even one coherent object but a variety of wires extended in front of a backdrop on which is painted what we took to be the seat of the chair.) Thus only one of the chairs which we see in this experiment is a real chair, while 129 the other two are illusions.^^18^^

p The illusion arises because of all the interpretations possible -(of all the object-hypotheses) corresponding to the given retinal patterns, the subject unconsciously chooses the one which accords best of all with his practical experience. Man continually handles chairs and does not as a rule encounter those strange objects which Ames demonstrated. All kinds of illusions are as a rule quickly dispersed in common practice: as distinct from the artificial conditions of laboratory experiment, in real life the subject does not just look at a given object from one position, and with one eye at that, but continually shifts his position, moving and acting vigorously, practically using various objects and creating new ones. All of this ensures quite sufficient conditions for correlating knowledge with real objects, singling out a fleeting perceptual image as an illusion and separating it from impressions corresponding to real objects. A stick immersed in water seems broken. The illusion in this case is not due to distortion of sensory information: the objective circumstances are such that the physical image of the stick on the retina cannot be different here; we know that the light refraction angles are different in the air and in water. The impression of the unusual arises here because in ordinary practice we do not deal with objects in two mediums simultaneously, in water and in air, so that our object-hypothesis cannot correct the distortion of the projection of the stick on the retina, as it is done by the subject perceiving the size and form of objects seen from different angles (“ constancy of perception”). But once one starts handling that same stick (and that usually happens when it is not half in the air and half under water), one perceives it as straight, i. e., as it actually is.

p Thus the objective properties of objects perceived are singled -out in practical activity in accordance with the tasks of that activity. E. H. Gombrich, the well-known art critic and specialist in the psychology of the perception of painting, remarks in his account of the Ames experiments with chairs that a hypothetical man from Mars who is used to furniture of the same kind as the strange objects demonstrated by Ames rather than our ordinary chairs, would perceive the latter as the familiar arrangements of wires (in any case, that would be his original perception, until he found out that chairs are real objects of our world).^^19^^ But it is exactly this circumstance, that is, the intimate links between perception and the immediate practical needs, that conditions not only the strong but also the weak points of perception. Practice does not simply 130 compel us to perceive the real characteristics of objects. The narrow limitations of practice may be the source of stable mass illusions that cannot be eliminated, such as the impression of the immobility of the Earth and the motion of the Sun. The conscious reflective cognition operating with abstractions ignores the urgent needs of practice and endeavours to discover the essential characteristics of objects irrespective of their appearance in a concrete situation. That does not mean that theoretical thinking in general isolates itself from the tasks of practice, opposing itself to the latter: it only means that thinking is an instrument for finding out the necessary characteristics of objects and at the same time the essential dimensions of practice itself. This ensures the possibility of action under conditions which appear unusual and unfamiliar in terms of available experience. When scientific astronomy dispelled the illusion of the Sun’s movement and immobility of the Earth (this illusion nevertheless persists in the perception of a person as long as that person remains on the Earth, for it fully accords with the ordinary practice of taking the Earth for a frame of reference), the possibility was thereby established, in the most abstract form, of future unusual and novel practice-^that of space flights, which provides a fresh view of the mutual motions of the Sun and the Earth.

p Although in principle theoretical thinking is capable of establishing the object’s proper, real characteristics, it may under certain conditions persist in reproducing stable illusions. Theoretical thinking (mostly in the social sciences) may be closely linked with a narrow, restricted practice of a definite kind persistently thrusting on the subjects the perception of apparent aspects of reality only. Of this nature is, for instance, the well-known phenomenon of "commodity fetishism" discovered by Marx, which is a mass objective illusion inevitably shared by the proponents of the capitalist system of social relations and reproduced by the vulgar bourgeois political economy.

p Marx was able to overcome this illusion theoretically only because he accepted the position of the proletariat’s revolutionary practice, which went beyond the activity in the framework of the bourgeois mode of production, assuming as it did a radical transformation of the latter.

p Of special interest are the perception illusions in which the perceptive image to some extent or other directly contradicts sensory data, partially rejecting them. This happens when the image of an object corresponding to sensory data is too extraordinary and deviates from common practice. A suitable example here is the perception 131 of the image of a head turned inside out, e. g., of the inner surface of a casting mould or of a plaster mask. Such an illusion expresses not only the weakness but also the strength of perception. The perception hypothesis in principle behaves in the same way with regard to sensory “facts” as theory with regard to the facts of science.

p However, the replacement of one perception hypothesis by another, is, as a rule, a more difficult matter, than the replacement of scientific theories or even paradigms, for perception object-hypotheses are too intimately connected with ordinary human practice. In this connection, the problem of perception of unusual objects arises, which is particularly acute _Ntoday when man has created a world of supercomplex technical apparatus often behaving differently from the ordinary bodies of everyday experience. Let us emphasise once again one of the most important features of the cognitive relation. On the one hand, what is given to the subject in the act of cognition is the really existing object and not his own subjective sensations. The objective image is not realised as a specific thing requiring special activity of objectif ication or projecting for its correlation with the external object. On the other hand, cognition necessarily assumes a realisation of the difference between the subject and the object cognized and, consequently, a realisation of the difference between the objective image belonging to the subject and the actual object itself. True, under ordinary conditions, when cognition is directed at the external object rather than the subjective world, the realisation of the subjective relevance of the objective image belonging to the subject is, as it were, at the periphery of consciousness, while the centre of the consciousness field is occupied by the real world of external objects. In this case, the objective image is “ transparent”, as it were, to the object presented in it. However, even when consciousness is oriented at the world of one’s own inner experiences (and that orientation is secondary, derivative from the orientation at the external world), the object (in this case the state of consciousness) and the subject of cognition do not merge, being separate from one another.

p The subject may be involved in cognizing objects of at least three kinds: objects external not only with regard to his consciousness but also to his body; his own body (reference here is to my body only, and not to the body of another subject); and finally, his consciousness. Cognition which deals with the objects of the first kind is primary, basic, and determining all the other types of knowledge. This cognition necessarily presupposes the presence 132 in consciousness of an objective world scheme incorporating also the scheme of the subject’s body as occupying a definite objective spatial-temporal position in the world among other objects. (If the subject does not realise the objective position of this body in the world, he cannot orient himself in the objective medium.) Cognition of one’s own body, on the one hand, assumes that some of its states are given to the subject "from within" (through proprioceptive reception), and on the other hand, it is based on the realisation of the body being incorporated in the objective network of the world’s connections in which the subject’s body itself acts as one of the objects.

p Thus the objective knowledge that I can pass on or communicate to other persons presupposes the existence of objects external with regard to my body and independent of it, and incorporation of my body in an objective network. As for the knowledge of the states of my consciousness, it only proves possible because I can view myself as if I were some other person, which implies not only the existence of that other person outside myself but also joint activity with him. (That does not exclude the existence of such shades in the realisation of my inner experiences which are rather hard to express externally and to communicate to someone else.) And that means that the realisation of the subjective states of consciousness presupposes objective knowledge as the necessary basis and would be impossible without it.

p Let us imagine that all objects of cognition are created, as it were, by the act of consciousness and do not exist outside cognition. It may appear that this hypothetical picture corresponds to the world of inner experiences of a child at the early stages of the development of the psyche, when objective perception of reality has not yet been formed and differentiation between the subjective and the objective is non-existent. But this view is unfounded. First, the early stages of the development of the psyche contain the possibility and the necessity of the subject’s subsequent conscious differentiation between his subjective states and the world of objects; second, the hypothetical picture of creation of objects by the very act of their cognition presupposes the realisation and recognition of the primacy of the subject and the derivative nature of objects, whereas in fact the baby does not originally realise even himself as a subject, far from realising the existence of objects.

p It is not hard to show the impossibility of the situation assumed here, for even the subjective states of consciousness cannot be fully determined by the cognitive activity 133 aimed at them, although the relation between subject and object in the process of reflexion is characterised by certain difficulties, which we shall later discuss. The states of consciousness and the subject’s body certainly do not exist independently of the subject himself. But their cognition, as we have stressed above, is only made possible by the subject realising himself as incorporated in the objective world, that is, a world filled with real objects and other subjects existing outside and independently from him. Most of the objects and other subjects are independent of the given subject both in their origin and their existence. (Some of them are independent of him in their existence but dependent on him in their origin: these include, first, the objects created by man, and second, his children.) If the objects were “tied” to the subject and “followed” his movements and actions, the cognitive relation would simply be impossible.

p This fundamental characteristic of cognition should be borne in mind, in particular, in discussing the philosophical implications of the modern theories of quantum mechanics. Both in the physical and the philosophical literature one can come across statements to the effect that the distinction or boundary between subject and object is obliterated in cognizing the objects of the microworld, and that man in this case deals with the cognition of his own action on the object of knowledge. These arguments are sometimes linked up with the dialectical materialist doctrine of the unity of the subject and the object, with the Marxist thesis of the active, practical nature of cognition. In reality, the philosophical significance of the cognitive situation in quantum physics lies in the discovery of a fundamentally new type of real objects possessing properties sharply distinguishing them from the ordinary objects of the macroworld, and in the need for taking into account the conditions of observation in describing experimental results. At the same time quantum mechanics provides no grounds for the assertion that the boundary between subject and object is eliminated. The point is that the conditions of observation referred to here are quite objective. The macro-devices and micro-objects exist outside the subject. The subject conducting the experiment and recording the apparatus measurements may in principle be replaced by an automaton.

Of course, man also cognizes the products of his own creativity. But that is only possible insofar as these products (e. g., the world of technology, cultural artifacts, scientific theories, works of art, etc., in the form of signs and symbols) function in the externally objective mode, 134 that is, outside the subject’s body. In any case, the process of cognition, of conscious reflection of the object, cannot coincide with the process of creating it. (Cognition itself is always creative in nature, but we have in mind here only the reproduction of the cognized object in the system of knowledge and not its creation.)