27

p The problem of objective reality has been frequently treated in the work of Max Planck, Albert Einstein, Niels Bohr and other great reformers of science. It was dealt with, in particular, in Max Born’s paper Symbol und Wirklichkeit which very definitely expressed a philosophical position typical of many contemporary scientists in the West.¹ Physicists who are the conscious adherents of dialectical materialism have also occupied themselves with the problem of objective reality and its various aspects.^^2^^

p The philosophical needs of science have thus turned out to be stronger than the statements of the modern positivists who declared objective reality to be a pseudoproblem. By its fundamental spirit science cannot consider nature other than as it is, without arbitrary additions by the cognising subject that are alien to it, and this means that it cannot help being materialist. This is the reason for the ineradicability of scientific materialism and indestructibility of the spontaneous, philosophically unconscious belief of most scientists in the objective reality of nature reflected by human consciousness. There is no need to cite here the many statements of distinguished contemporary scientists about the objective nature of science, and that a physicist, say, is dealing with objective reality and should consider his sense impressions as messages about this reality and not as illusions.^^3^^ Humanity’s belief in the objective reality of the external world reflected by science is a conviction of twentieth century scientists that is necessarily becoming stronger,

28

p Scientists’ spontaneous, philosophically shapeless materialism is inseparably connected with philosophical materialism; but it cannot, precisely because of its lack of philosophical shape, cope with the philosophical problems posed by the development of modern physics, and that is made use of by trends opposed to materialism. These philosophical problems include, above all, the problem of objective reality itself.

p The point is that the question of the objective reality of matter in motion and its particles, of space and time, of the regularity in nature could only be formulated and considered consistently from the point of view of materialism by dialectical materialism. All materialist theories before Marx and Engels brought to the fore in philosophy not so much the question of the objective reality reflected by the human consciousness but that of the ultimate reality, like the ‘final’ atoms, the ’absolute substance’ (compare Democritus’ differentiation between the existence of colour, heat, bitterness according to opinion, on the one hand, and of atoms and the void, according to truth, on the other hand, Locke’s and Hobbes’ distinguishing between primary and secondary qualities, and the ’constant masses’ or particles of the mechanistic picture of the world in physics). Pre-dialectical materialism unjustifiably raised one property of matter or another, which was characteristic only of certain states of matter, to the level of an absolute, a universal property of matter, so turning it into an ’invariable element’, the ’invariable essence’ of things. Lenin criticised this metaphysical position as follows: ’From Engels’ point of view, the only immutability is the reflection by the human mind (when there is a human mind) of an external world existing and developing independently of the mind. No other “ immutability”, no other “essence”, no other "absolute substance", in the sense in which these concepts were depicted by the empty professorial philosophy, exist for Marx and Engels. The “essence” of things, or “substance”, is also relative; it expresses only the degree of profundity of man’s knowledge of objects; and while yesterday the profundity of this knowledge did not go beyond the atom, and today does not go beyond the electron and ether, dialectical materialism insists on the temporary, relative, approximate character of all these milestones in the knowledge of nature gained by the progressing science of man.’^^4^^

29

’Invariable elements’ and other metaphysical ’ invariabilities’ thus represent the purest subjective constructions, alien to nature. Objectively real nature itself is both diverse and united, complex and simple. By isolating classes of natural phenomena, by formulating concepts and categories of various degrees of generality man pursues a goal—to catch the many-sided phenomena of nature in the net of knowledge. But that means this, that the cognising person connects up the field of experience isolated by him in a single totality of phenomena or wholeness that appears before the mind cognising it in its most varied aspects. How do we know that nature is united in its diversity and diverse in its unity? That it contains no ’ultimate realities’? We know this from the development of human knowledge, the history and logic of which demonstrates that the simple in nature passes into the complex, and the complex into the simple, that everything different in nature merges, that in the course of development of knowledge man cognises nature more deeply and more fully without exhausting it completely. Cognition of nature’s objective reality is cognition^of nature as it is, in other words, cognition of nature as matter in motion.

p Let us first recall certain definitions and formulate the problem itself. The ’objectively real’ or the ‘objective’ or the ’objectively existing’ means what ’exists regardless of human consciousness and (in certain conditions) reflected by it’. Unlike the objective, the ‘subjective’ means what ’exists in consciousness’. The concept of the objective (from the point of view of materialist philosophy) coincides with that of matter from the aspect of the theory of knowledge; according to Lenin, ’the concept matter ... epistemologically implies nothing but objective reality existing independently of the human mind and reflected by it’.^^5^^ In accordance with that (materialist) understanding of the objective and subjective, cognition is a process of reflection of the objectively real world in man’s mind. By creating concepts, theories, and a picture of the world, man takes in an approximate, relatively universal pattern of constantly moving and developing matter through them.

p It follows from what we have said that the ’objectively real’ (or ’objectively existing’) is not equivalent to what 30 ‘exists’ since ’existence^^1^^ is also possible hi the mind. The confusion of these concepts and the issues related to them— which is wrong in itself—opens the road to an idealist outlook. A vivid example of this is provided by the ideas of Rudolf Carnap, one of the leading spokesmen of positivism in the twentieth century. According to him, if one accepts the language in which statements about objects that are dealt with in physics are formulated, then whether phlogiston, say, or ether exists has to be answered by empirical research. But to ask about the existence of a system of physical objects as a whole, i.e. of the physical world, is meaningless, as Garnap sees it, since the answer cannot be formulated in terms of the accepted physicalist language. ’To be real in the scientific sense,’ he wrote, ’means to be an element of the system; hence this concept cannot be meaningfully applied to the system itself.’^^6^^

p Carnap’s very posing of the question of the real (or the existing) presupposes a non-materialist answer. In his argument he started from the ready-made knowledge expressed in language and ignored the problem of the origin, source, development, etc., of knowledge from the very outset, in other words, he considered knowledge (and language, since the latter is used to express knowledge) in fact as the primary element and, therefore, supported an idealist point of view (which he appeared to disown). In reality Carnap dealt with the problem of the meaning of subjective constructions (expressed in language) and wrongly substituted it for that of objective reality. How do we know, however, that things do exist independently of our consciousness? According to Lenin, this knowledge springs ’from the development of our knowledge, which provides millions of examples to every individual of knowledge replacing ignorance when an object acts upon our sense-organs, and conversely of ignorance replacing knowledge when the possibility of such action is eliminated’.^^7^^

p In Marxist-Leninist philosophy the materialist solution of the major problem of philosophy is thus inseparably linked with the dialectics of the process of cognition in contrast to metaphysical materialism.

p The philosophical problem—i.e. whether the statements of physics expressed in mathematical formulas have objective meaning, or from what one can deduce that the statements of physics are not pure subjective constructions, or 31 how objective knowledge is achieved—had already appeared in classical physics. And it is the problem of objective reality in the physical sciences in its most general form.

p In the science of the classical period, the solution of this problem did not seem particularly difficult, though it had its complex elements. Most naturalists then, as now, did not rack their brains over philosophical niceties. For them acceptance of the objective reality of the external world reflected in our mind was common sense. The phenomena observed were explained by a mechanical macroscopic model. The observation of motions of macroscopic bodies (including the motions of the celestial bodies then known) did not call for particularly precise special equipment. The degree of abstractness of the concepts which expressed the measurable characteristics of these motions (velocity, acceleration) was not very different from that of notions developed in everyday experience.

p Classical theory, however, could not by-pass the problem of objective reality. How could one know that the ‘green’ one saw was the same ‘green’ seen by another observer? This was an example from everyday experience, but classical physics frequently based its conclusions on such experience. Our analysis will begin exactly with just this example.

p The question posed is, as a matter of fact, the question whether the sensation ‘green’ corresponds to something objective. The answer given by practice is positive: to answer it, it is sufficient to imagine a driver who is daltonian or colour-blind. The fact that we know about colour blindness and can avoid its undesirable qualities to some extent, moreover, only confirms another fact, that the sensation ‘green’ corresponds to objective reality.

p As for the problem of reality, analysis of such cases does not differ essentially from analysis of measurement procedure and of experiment in general, the direct task of which is the recording of macroscopic parameters. All physical theories, both classical and non-classical, grew from measurements and experiments through study and thinking (when the cognitive power of abstraction becomes greater and greater). If we generalise what we have said, taking into account data from the most varied branches of science and practice, we come to the well-known premises of materialism (formulated by Lenin with classical clarity): the sole source of 32 our knowledge is sensation; objective reality is the source of human sensations or, which is in fact the same thing, the external cognisable world exists independently of human consciousness.^^8^^

p Max Born, in his work already mentioned, does not agree with this fundamental statement of materialist epistemology. True, he does not express himself against it in essence; on the contrary, he criticises idealism and apriorism, especially the views of Kant, Machists, and logical positivists. He does not consider Lenin’s statement to be proved, however, and wants to justify his own position by relying, as it seems to him, on modern physics. (Bern’s paper has a typical subtitle: ’An attempt to philosophise in a scientific way is not a philosophy of natural science.’) Is he right?

p According to Born, the impossibility of answering whether the ‘green’ I see is the same ‘green’ that he sees rests on the fact that in this case ’one is trying to understand a single sensation’.^^9^^ Such an ‘understanding’ is, indeed, impossible; Born sees the way out as follows. ’Even for two impressions of the same sensory organ, for instance, for two colours, the communicated, objectively verifiable statement is specified— which rests on comparison, first of all, on the judgment concerning identity or non-identity (in other words, indistinguishability or distinguishability...). I cannot transmit my feelings to another person when I call something green, but I can, and he, too, establish that when the green of two leaves appears to me identical, it also appears identical to another person.’^^10^^

p Born is saying here essentially that objective knowledge is not what corresponds to the objectively real but rather to the common meaning. After Lenin’s criticism of the views of Bogdanov, who defined the objective as the common meaning, there is no need to discuss the erroneousness of Born’s idea further. On the other hand, the example of ‘green’ serves Born to stress the idea of invariance, use of which, in his view, makes it possible to solve the following problem: how is the passage from subjectivity to objective knowledge made? (Born developed his understanding of this matter in greater detail in other works.)^^11^^ From this last standpoint the idea of invariance presents great interest, but before we discuss it let us consider whether Lenin’s statement above on the fundamental premise of the materialist theory of knowledge is, in fact, not proved, as Born suggests.

33

p In trying to resolve how the passage is made from the subjective to objective knowledge, Born did not see the question behind it of objective reality being the source of sensation (and therefore of subjectivity). In Born’s work one can read: ’Subjectivity as primary and the possibility of objective statements as a problem.’^^12^^

p This statement of Born’s agrees with science only when it is associated with another to the effect that ‘subjectivity’ itself is generated by objective reality; but this last statement cannot be found explicitly in Born’s works. In short, his argument by-passed the basic question of philosophy (or, more precisely, its primary aspect) of the relationship between mind and matter and its solution by materialism. In Lenin’s Materialism and Empirio-criticism (Section I of Chapter III, which is entitled ’What Is Matter? What Is Experience?’) there are epistemological and logical proofs of the need to accept the fundamental propositions of materialism.

p The problem of objective reality became more and more confused in physics from the time it began to leave the macroscopic objects perceived in everyday experience for the sphere of phenomena whose cognition called, in addition to very refined, specialised experimental equipment, for nonclassical theories with their abstractions unknown to classical physics.

p Even before non-classical physics had been created, Engels remarked that ’atoms and molecules, etc. cannot be observed under the microscope, but only by the process of thought’.  [33•*  The deep insight of his words became completely apparent when physics began, so to say, to come closer and closer to the foundation of matter. It is impossible to manage in physical theories without abstractions and mathematics. In Boltzmann’s kinetic theory, and in Einstein’s theoretical work on molecular theory, the heuristic significance of mathematics was revealed with all clarity: their works led 34 to Perrin’s decisive experiments, and the molecular-atomic structure of macroscopic bodies became a demonstrated fact. What was the situation here with the problem of objective reality?

p In classical physics (and that includes the studies of Boltzmann and Einstein mentioned above) it was sufficient, in order to explain the phenomena observed in the instruments, to link the observed data by chain of appropriate reasoning (with the addition, where necessary, of assumptions of one sort or another) with the system of basic concepts and axioms of classical mechanics. As for the problem of objective reality, it meant that the transition from what had been observed in the apparatus to knowledge about the objects being studied could be reduced to the construction of some mechanical macroscopic model. Classical statistical physics, as we know, rests in fact upon the fundamental notions of classical corpuscular mechanics.

p In the science of today the problem of objective reality has assumed a form differing from that it had in classical physics. At the turn of the century paradoxical situations emerged in physics when the data of observations could not be fitted into the theoretical schemes and conceptions then existing. Such were the situations encountered by physicists in connection with the Michelson-Morley experiment, in connection with the facts that were called the ’ultraviolet catastrophe’, in connection with Rutherford’s planetary model for the atom (1910-12), and at the end of the twenties in connection with certain facts, including direct experiments, that made it necessary to ascribe properties to electrons (which no one had seen) that were mutually exclusive from the standpoint of classical physics. As a matter of fact, it was only then that the problem of objective reality took on the form in which it appears in modern physics (these situations were, of course, the starting points of non-classical physical theories).

p It is possible, of course, generally speaking, to try and interpret paradoxical situations by varying the schemes of classical explanations in one or another way. Such attempts are still being made; one can cite as an example Janossy’s interpretation of the theory of relativity, or the interpretations of quantum mechanics of, say, Schrodinger or David Bohm. On the abstract level there is nothing unjustifiable in such attempts. But still, the problem of the truth of the 35 relevant interpretations is decided according to the fruitfulness of the results obtained, and here the development of physics has a weighty word to say: the theory of relativity and quantum mechanics have become established as nonclassical theories, i.e. as theories that employ mathematical abstractions inapplicable in classical physics and also basic concepts and principles that differ from classical ones.

It appeared to many at one time that the problem of objective reality in physics had been removed by positivism, whether that of Mach or of modern logical positivists, which declared only the world of sensations to exist, so to say, without objective reality. From that point of view, nature for Margenau, for, instance, ceases to exist beyond the experiment, and proves to consist of sensory data and conceptual ‘constructions’ (things from everyday life, atoms, electrons, etc.) since they emerge through experiment from ’chaos or non-being’.^^13^^ According to him, the real is only that which acts either on the objects or on the human psyche; outside that action it is not real. ’What is not real in the Roman sense,’ he says, ’may well be real in this. God, according to this version, is real to the person who believes in Him.’¹⁴ The only way out of this situation is to join Born who said, in criticising the ideas of this kind of positivists and other anti-materialists: ’Whoever believes that the only important reality is the realm of ideas, of the spirit, should not occupy himself with science.’^^15^^

p The development of modern physics occurs through the passage of some fundamental theories into others, more general (and deeper) and differing qualitatively from the former. The disappearance of certain basic concepts (that figure in the original theory) and the formation of new basic concepts (without which the new theory is not a theory) is necessarily associated with generalisations of this sort. The disappearance of old concepts and the appearance of new basic ones is a single process in which the old concepts (in the original theory they were absolute concepts or invariants of sorts) undergo a kind of relativisation and become aspects of new absolute concepts or the invariants in a more general theory. In the theory of relativity, for instance, the concepts of absolute length and absolute duration accepted in classical mechanics disappeared, and relativistic concepts 36 of length and duration became established; they represent the aspects of one of the most important invariants in the theory of relativity—the four-dimensional interval which represents a special ‘combination’ of length and duration. In quantum mechanics the absolute nature of the corpuscular and wave concepts inherent in them in classical theory is lost; these concepts become relative ones, as aspects of a broader concept (than the classical one) of a particle with certain invariant characteristics, which is applied to atomic objects.

p Those two examples help express certain considerations on the epistemological plane about the idea of invariance. First of all, one cannot agree with Born, who ascribes reality in essence only to invariants and, so to say, denies reality to aspects of invariants. The justification for recognising the objective significance of physical concepts or statements does not consist in the idea of invariance. Suffice it to recall that the relativistic concepts of length and duration correspond to objective reality (this has now been confirmed by direct experiments) and are not invariants of the theory of relativity. In other words, both invariants and their aspects are images of objective reality.

p At the same time, the idea of invariance plays a major role in the question of the transition from subjectivity to objective knowledge. The concepts of classical mechanics and the science as a whole, for instance, are, of course, essentially approximate. This was demonstrated concretely from various aspects by the theory of relativity and quantum mechanics when they determined the limits of applicability of classical mechanics itself and of its concepts. Thus, the uncertainty principle in quantum mechanics established the limits of applicability of the classical concept of a particle (absolute in a certain sense). In this case in determining the limit of applicability of the classical concept of a particle, attention was given to the fact that, let us say, electrons and protons possess wave properties as well as corpuscular properties. To put it differently, the establishing of a limit to the applicability of the classical concept of a particle meant deeper knowledge of the particles of matter than was possible in classical mechanics. Beyond these limits, of course, the classical concept does not ‘work’, i.e. has no objective meaning and represents a subjective construction.

p In general, when one bears in mind a number of major modern physical theories of an increasing degree of generality 37 (classical mechanics—quantum mechanics—quantum electrodynamics—quantum field theory or the theory of elementary particles) one can say that the relativisation of old absolute (invariant) concepts, and the introduction of new ones, during the generalisation of a theory mean progressive movement from the subjective to objective knowledge, deeper and deeper cognition of objective reality in which the onesidedness (and subjective constructions inseparable from it) of individual physical theories is obliterated, as it were, and the theories themselves, while preserving their content which corresponds to objective reality, acquire a higher integrity.

p That, it seems to us, is the philosophical significance of the idea of invariance in the problem of objective reality in modern physics. In non-classical physics, which poses the question of the reality of its objects, Lenin’s ideas on the relation between the objective and the subjective find expression. The objective and the subjective, matter and mind oppose each other and preserve their absolute opposition only within the limits of the main question of philosophy: namely, that of the relation between mind and matter since no mind exists or can exist outside and independently of matter. ’To operate beyond these limits’, said Lenin, ’with the antithesis of matter and mind, physical and mental, as though they were absolute opposites, would be a great mistake.’^^16^^ The situation is also exactly the same in modern physics when the question of the objective nature of its statements is discussed; a striking example of this is the application of the idea of invariance in it.

p ^WBohr’s concept of complementarity acquired essential significance for the problem of the objective and the subjective in modern physics. We shall discuss it separately in the following sections and in other chapters; here we shall make only a brief comment about the problem involved.

p Complementarity has frequently been regarded as referring to the subjective observer, which is incompatible with the objective nature of the scientific description and the cognition of the phenomena of nature. This applies both to physicists who share Bohr’s ideas, and those who do not, especially to idealist philosophers, and positivists in particular. Bohr himself, Heisenberg, and many other distinguished scientists spoke against such a view.

p In his essay ’Atoms and Human Knowledge’ (1955), Bohr mentioned that it was necessary, of course, in every field of 38 experience to ’retain a sharp distinction between the observer and the content of the observations’. But ’discovery of the quantum of action’ had ’revealed hitherto unnoticed presuppositions to the rational use of the concepts on which the communication of experience rests’. And he posed the question of whether one could draw a sharp line in experience between the cognised object and the cognising subject, the observed system and the instruments used for observation. ’In quantum physics,’ he said, ’an account of the functioning of the measuring instruments is indispensable to the definition of phenomena.’^^17^^

p Bohr did not employ the term ’initial-state preparation’ which would have clarified his idea in this case; he also did not use the term ’relativity to the means of observation’. These terms would have helped clarify more deeply the meaning of his main ideas and make the general line of his reasoning easier to understand. They have been used by other authors.^^18^^

p In his works on quantum mechanics and its philosophical problems Bohr, as a matter of fact, demonstrated that the concepts of the subjective and the objective, which were interpreted in classical physics as separate concepts with an absolute difference between them, required revision. With deeper analysis of this problem in terms of the content of quantum mechanics, the difference between the subjective and the objective proved to be relative. This analysis also made it possible to establish that classical physics’ understanding of the objective and the subjective was not rejected, generally speaking; it remained valid, but within certain limits that could be and are being made more precise as physics develops.

p Materialist dialectics opens up the necessary paths here for resolving the paradoxes emerging. We would like to emphasise once more that the significance of Lenin’s ideas on the relation between the objective and the subjective is especially great in this case for physical problematics. The following remark of Lenin’s is very important in this connection: ’There is a difference between the subjective and the objective, BUTIT, TOO, HAS ITS LIMITS.’¹⁹ We shall return to the questions raised here in the appropriate places in subsequent chapters.

p To conclude this section, we would say a few words about a fact that can, in particular, illustrate a well-known 39 thought: if a physicist ignores materialist dialectics during his analysis of his science’s philosophical problems in certain conditions this science will turn in his hands into an ally of sorts of reactionary philosophy. In Heisenberg’s Der Teil und das Game he presents the following point of view: whereas it used to be difficult to find a place for religion in the conceptual system of classical science the situation is now different. This is because, according to him, of ’the emancipation of our thinking’ that has resulted from the ’development of physics in recent decades’, which has demonstrated ’how problematic the concepts “subjective” and “objective” are’.^^20^^

p Heisenberg had in mind the alteration and refinement of these concepts in the theory of relativity and especially in quantum mechanics (compared with classical theory) discussed above, which are evidence of a new triumph of materialist dialectics in physics. He, however, interprets this change as physics’ rejection of materialism.

In what follows we shall continue our discussion of the questions raised above.