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REALITY

13. The Preservation of Reality

We must, however, guard against going to the opposite extreme from Comte and claiming that the form of modern science is uniquely, or at least espe­cially, due to the influence of mathematics. In fact, a glance through the history of physical concepts suffices to show that this form - which is, or at least was until Einstein, that of a mechanism (in Chapter 19 we shall deal with the connection between mechanism and relativism) - was already found in all its essential traits in antiquity, when mathematics properly speaking played only an insignificant role. The true motivating force was the concern to preserve the identity of reality discussed in § 7.

Indeed, the tendency to mathematicize physics dealt with in Chapter 1 is, if not actually under attack by, at least dominated by this other tendency, which is truly characteristic of science as distinct from philosophy strictly speaking and which attempts to preserve the reality of the representation that theory means to substitute for the common sense representation.

14. Sensation and the Object

The concept of an external reality, as presented in the spontaneous ontology of our perception, is born of our constant effort to explain our sensations. Because we cannot conceive how they go about changing, we assume that they depend on some cause more constant than they are, a cause we are consequently obliged to place outside our consciousness. This object is thus, first of all, a collection of sensations projected outside the self, that is, hypostasized. But these sensations are not limited to those I actually ex­perience; on the contrary, the latter play a relatively unimportant role com­pared to the sensations that, largely as a result of my memory, I consider it possible to experience. An object is not the hypostatization of fleeting visual, tactile, or olfactory, etc., sensations; it is the hypostatization of the collection of sensations of all sorts that I remember having experienced in a great number of circumstances, or that I imagine I ought to experience in a given circumstance. Moreover, one can readily see that, in the concept of object,

18

É. Meyerson, The Relativistic Deduction© D. Reidel Publishing Company, Dordrecht, Holland 1985

REALITY 19

these potential sensations prevail over our actual sensations to the point that, as Bergson says, "perception ends by being merely an occasion for remembering." 1 Consequently, these sensations, which we could only ex­perience successively and which would obviously be quite ephemeral, are transformed into simultaneous properties of an object persisting in time. When I touch the end of the handle of my umbrella in the dark, I recognize it; I have no doubt that it is there in its entirety, with its metal ribs and the silken fabric that covers it, and even that the handle is made of wood, that is to say, has a well-defmed internal composition.

15. The Search for Consistency

Thus, it is a collection of ephemeral and apparently contradictory sensations that I try to explain in my obstinate search for consistency, for the 'concept of totality' that constantly intervenes in our thought processes, as HOffding showed with his characteristic clarity and depth in a recent work.2 I endeavor to show how, taking into account the diversity of the circumstances, these sensations can nevertheless result from a persistent and unique reality, from a truth to be found behind these appearances. Plato already realized this, showing that when different observers conceive differently the size and shape of one and the same thing, it is still possible, by means of number and mea­surement, to form a unique concept that explains this diversity.3 Surely this is also the meaning of Spinoza's well-known apothegm, "Truth [is] a standard both of itself and of falsity."4 Furthermore, no one could doubt that this is the principle the scientist follows in his research. HOffding, whose exposition we are following here, has shown to what extent the entire work of Galileo in particular seems to proceed from this point of view. When he found himself confronted by an anomaly that was none other than the phenomenon we today call the rings of Saturn, it was because his imperfect telescope made him see, in this object he justifiably supposed to be unique, images he found impossible to reconcile with one another. But Huygens later succeeded in demonstrating what was actually involved and how this reality explained the appearances that had deceived his predecessors. 5

16. The Objects Created by Science

It should be pointed out that the truth sought by Galileo and found by Huygens is an object whose reality is in all respects analogous to the reality of common sense objects. Although no one before the invention of the

20 CHAPTER 2

telescope could have had the slightest idea of the rings of Saturn, we no more doubt their existence today than we do that of any object whatsoever per­ceived directly by our sense organs. Why should we be surprised by this? Is it not clear that in the two cases we are concerned with entirely analogous concepts? For even if we were to admit, as is sometimes assumed, that touch is the true sense of the real and that we are therefore immediately convinced of the existence of objects we are able to touch,6 it is certain that such objects are rare compared to the sum total of what seems to us to constitute the real world and which is revealed to us principally by the sense of sight. Now the sense of sight - as a glance at a mirror is sufficient to convince us -is subject to countless illusions. Thus, our belief in the reality of the objects we perceive is, and in the great majority of cases must be, only the result of a more or less complex process of reasoning; this reality seems necessary to us in order to explain our sensations. From this point of view, the situation is exactly like that of the theoretical entities of science, the only difference being that what causes us to posit the existence of the latter is not simply the impressions of our sense organs but the impressions of these organs as they have been refined by the use of instruments.

Common sense objects and theoretical entitities are so much of the same nature that there is a continual, and quite often imperceptible, transition between the two classes. Surely, for our ancestors the stars were nothing but simple luminous points fixed to the celestial vault. They have undoubtedly remained just that for a large part of humanity today, and one can recall that even Hegel compared them to eruptions on the skin.7 For any of our contemporaries with the slightest degree of sophistication, they are, on the contrary, immense celestial bodies, whose reality can no more be doubted than that of the incandescent mass of the sun. Furthermore, in earliest antiquity the sun itself was often considered to be a purely ephemeral and immaterial luminous phenomenon.8 Surely it would be quite impossible to identify the moment at which these essential transformations occurred. It is not even necessary that the objects created by science actually be perceived, with or without the aid of optical instruments, in order to become real; their existence can simply be inferred, in the same way that an entity that is initially entirely hypothetical can later become just as completely real if the inferences become more numerous. Molecules and atoms were certainly only theoretical entities from the time of Democritus to the present era, whereas they have undoubtedly become a part of physical reality since the work of Gouy, Perrin, and the Braggs. And nothing is more certain than the fact that we infer their existence by reasoning analogous. to that by which common

REALITY 21

sense is persuaded of the existence of any object whatsoever, namely because this assumption accounts for a whole series of observed phenomena.9

17. The Attitude of the Philologist

Moreover, this very characteristic attitude of the human intellect is not seen exclusively in the case of common sense and the physical sciences; it can be seen in connection with all research. For a specific example, take the case of a philologist trying to establish the original text from the more-or-less altered readings transmitted to us through different manuscripts. He certainly will not be able to consider his task completed until he can explain how the ob­served alterations could have crept into the text in question. "The apparently correct reading," Loisy said, in describing how Renan went about studying a Biblical passage, "had to account in some way for the apparently less prob­able or false readings that were supposed to be derived from it; only after this final test would Renan make a pronouncement."lO

18. Reality and Appearance

The philologist's procedure is undeniably based upon the conviction that there exists one text from which the others are derived; it is only this convic­tion that allows him to make a choice between the different readings, rejecting some in favor of others. In the same way, common sense does not attempt to include in the object absolutely all the sensations the object seems to be able to give it. Rather it declares some of them real, while others, even though they may actually be present, are judged to be merely apparent. The trees appear to be purple in the distance, but they are really green.

It may be instructive in more than one respect to consider this example further. First, it clearly shows that, contrary to what is sometimes said, memory is not simply a weakened sensation. In fact, in this case memory is stronger than momentary sensation, to the point that it may make the latter disappear, since until such time as we have learned to attend to the fleeting sensation, we are completely persuaded we see the color green where there actually is the color purple. Secondly, we also see the inadequacy of the theory that the primacy of the sense of touch is what convinces us that the dimensions and shapes of objects are invariable (even though our vision shows them to be constantly changing). For, in the case we are conSidering, what masks the immediate visual sensation is another visual sensation.

The truth is that this whole process is possible only because we are not

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dealing with things of the same order, contrary to what one would at nrst be inclined to believe. Although the color green of the tree was originally only a sensation just like the color purple, common sense reasoning has transformed it into a property of the thing, that is to say, has located it outside our consciousness. Therefore, as is indicated in our statement of the relationship between the two sensations, the green henceforth becomes part of reality, permitting it to be substituted for the sensation of purple, which is considered to be mere appearance. Thus, the sensation is entirely sub­ordinated to the perception; it seems to be only the sign pointing to the perception, the way leading toward it. The perception appears to be real, so much so that it sometimes succeeds in making us completely forget what served as its point of departure. As Brunschvicg aptly said, "the true nature of common sense is to turn spontaneously toward things" (EH 406).

Furthermore, it is this trait of our perception that makes prestidigitation possible. The clever performer can make gestures that deceive us, making us swear we saw something that never happened at all. Here again, it is not a question of a sensation, but of a perception, a snap judgment about an infe"ed reality, and it is this judgment that is responsible for our error.

19. The Positivistic Point of View

Thus, as a result of the circumstances just described, the common sense object is already seen to be necessarily detached in large measure from sensation. And the proof is that it continues to exist when I look away and no longer perceive it in any way.

This evolution continues in science. Such an observation is diametrically opposed to the most essential foundations of the positivistic position, as are the observations we have just made concerning the perfect similarity between the objects created by science and those whose existence is posited by a spontaneous act of perception. As a matter of fact, positivism, as we know only too well, would have science abstain from any assumption concerning the true nature of things. It does so by establishing a system of relations without any substratum, which can only result in a search for connections between our pure sensations, a procedure as remote as possible from the one actually used by science. It should be added that Auguste Comte himself, following his powerful scientiflc instinct and forgetting his own principles, proclaimed on occasion that the "crude but sensible indications of good common sense" constituted "the real and constant point of departure for all sound scientiflc speculation" (CPP 3:205). It is easy to nnd similar statements

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among our contemporaries, even those who seem to have quite orthodox positivistic credentials. Urbain, for example, declares that "science, the fruit of reason, is an extension of common knowledge." 11 The noted chemist was undoubtedly right, and it is completely impossible to practice chemistry in any other way than by following this principle.

20. Transcendence

The close relationship between scientific thought and the concept of a thing, considered as independent of sensation, was noted as far back as Lucretius. Malebranche sharpened this thought by pointing out that, insofar as they are subjective phenomena, sensations cannot be directly measured; one cannot be used to measure another. On the contrary, we must first reduce them to causes existing outside ourselves. Bradley has pointed out how difficult it is to form an idea of the laws of physics without recourse to the "transcen­dent." 12 A contemporary psychologist, Stumpf, has also stressed the fact that

the phenomena of sensation are never what observation uses to establish relationships conforming to laws, which relationships constitute the object and goal of science.

He points out that

regular succession, as well as coexistence ... occurs only in the case of events we place, and must place, outside sense phenomena; we are forced to consider them as happening independently of consciousness if we are to speak of lawfulness in general or in any way at all. 13

Thus science is necessarily and essentially realistic, in the philosophical sense of the term. As Marais justly said, "realism ... is the implicit postulate of any science of the external world." 14

21. The True Place of Theory in Science

It follows that hypothesis, or theory based on representations - far from being a parasitical excrescence ( as the strict positivist would have it), or even a simple auxiliary means, accepted temporarily only to be rejected later when one has achieved one's true end, which is law (as is assumed by the mitigated positivism that is the current epistemology among today's physicists) - is an integral part of what is most essential in science. For the scientist could not work without basing his thought on a body of assumptions concerning the

24 CHAPTER 2

substratum of phenomena. Hypothesis is indispensable to him, and whatever he professes to believe in this respect, there is always a hypothesis behind his explanations.

Positivism's error obviously arises from the fact that, although science starts out from the common sense conception, it profoundly modifies this position. This transformation, considerable though it may seem, nevertheless takes place, as we have just seen, according to exactly the same principles by which spontaneous perception constructed its world. Therefore, scientific theory ends up with a representation in exactly the same way as does the world of common sense. It follows from this (as we demonstrated in ES 1 :22 ff.) that the distinction between a science that explains and one that would abstain from all representation is much less real than is commonly claimed, because even the latter cannot get along without an ontology. The only difference between them is that, while the latter accepts our customary ontology, explanatory theories require us to modify it.

Moreover, the progression of a theory, that is to say, the successive changes in our assumptions concerning the nature of things, is itself necessitated by our desire to maintain, or indeed make more perfect, the consistency dis­cussed above, which is constantly being threatened by new observations. We desire a more and more rational reality, and it is evident from what we have said that science seeks to achieve this by continuing the evolution that led reason from pure sensation to the common sense object.

22. Planck on the Retreat from 'Anthropomorphism'

Planck has astutely observed that one of the strongest and most constant characteristics of progress in physics is precisely the fact that it is moving further and further from what he calls "anthropomorphic considerations," that is, those involving the person of the observer, or, in other words, what refers to the self. In a more recent work, the noted physicist again underlines this essential idea:

It is impossible to deny that the whole of the present-day development of physical knowledge works towards as far-reaching a separation as possible of the phenomena in external Nature from those in human consciousness.

And he adds:

The theorem holds also in physics, that one cannot be happy without belief, at least belief in some sort of reality outside us .... A research worker who is not guided in his work by any hypothesis, however prudently and provisionally formed, renounces from the beginning a deep understanding of his own results (PRB 78-79; Eng. 53-54).

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Completely analogous opinions are to be found in Wien.1t is true that this scientist, under the powerful influence of an environment that has long been the preferred atmosphere for the mind of the epistemologist, expresses himself on occasion somewhat like an orthodox positivist. For example, he welcomes the fact that

theoretical physics has gradually been stripped of all its metaphysical vestiges and has come to recognize that its principal task consists in formulating mathematically ex­pressed laws and deducing their consequences.

But at other times, when he is grappling with the real problems of science, he speaks quite differently. Thus, in the case of electron theory, he points out that this hypothesis shows us that, "in the quest for knowledge, we must remove ourselves more and more from sensible phenomena and the traditional concepts of physics." He gives his full approval to a statement by the philos­opher Kiilpe, according to whom the true criterion for the reality of a concept is its independence from the observing subject, adding:

The physicist cannot seek knowledge, nor in the final analysis can anyone else, without postulating a well-defined external world existing objectively and governed by immut­able laws.

In another passage he claims that "the foundation of physical thought can be considered" to be the tendency "to eliminate man's subjective conception and uncover the immutable and independent laws governing the way in which man observes things." 15

We shall have occasion in a later chapter (§51) to come back to Wien's allusion to the search for "immutable laws." For the moment, let us simply remember his important observation that scientific reality, by its nature as well as by its origin, resembles in all respects the reality offered us by spon­taneous common sense perception. At the same time we must note that if, in virtue of the process described by Planck and Wien, the entities created by science are destined to be substituted for those of common sense, they will necessarily be more detached, more independent of the subject, that is to say, more real, than the latter. This is true, for example, in the case of the atoms or electrons that are to replace the material bodies of our spontaneous perception.

NOTES

1 Henri Bergson, Matiere et memoire (Paris, 1903), p. 59 [Matter and Memory, trans. Nancy M. Paul and W. Scott Palmer (London: Allen and Unwin, 1911), p. 71].

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2 Harald Hiiffding, Der Totalitiitsbegriff (Leipzig, 1917), passim. 3 Plato, The Republic, X, 602C-603A. 4 Spinoza, Ethics, Pt. 2, prop. 43, note: veritas est norma sui et falsi [The Chief Works of Spinoza, trans. R. H. M. Elwes (Bohn Library ed.; reprint New York: Dover, 1951), 2:115]. 5 Hiiffding, Der Relationsbegriff (Leipzig, 1922), pp. 94-95. 6 Cf. below, § 170 ff., on the role of the sense of touch in the concept of material body. 7 Hegel, Naturphilosophie, Werke (Berlin, 1842), Vol. 7, Pt. 1, pp. 92, 462 [Hegel's Philosophy of Nature, trans. A. V. Miller (Oxford: Clarendon Press, 1970), pp. 62, 297]. 8 Gottlob Frege, 'Uber Sinn und Bedeutung,' Zeitschrift jUr Philosophie und Philo­sophische Kritik 100 (1892) 25, has rightly said that "the discovery that the rising sun is not new every morning, but always the same, was one of the most fertile astronomical discoveries" ['On Sense and Reference,' Translations from the Philosophical Writings of Gottlob Frege, trans. Max Black (Oxford: Blackwell, 1960), p. 56]. 9 Henri Poincare understood perfectly the extent to which our belief in the entities created by science is analogous to the one manifested in common sense. He has .even expressed this opinion in a particularly difficult case, that of the existence of the ether (it is well-known that many physicists today seriously doubt that it exists). Indeed, after having said that "this hypothesis is found to be suitable for the explanation of phenomena," he added: "After all, have we any other reason for believing in the ex­istence of material objects? That, too, is only a convenient hypothesis" (La science et l'hypothese, Paris, s. d., p. 245 [Science and Hypothesis, trans. W. J. Greenstreet (Lon­don, 1905; reprint New York: Dover, 1952), pp. 211-212J. Cf. below, §269, con­cerning the meaning of the term convenient. 10 Alfred Loisy, 'Le cours de Renan au College de France,' Journal de Psychologie 20 (1923) 327. 11 Georges Urbain, Les disciplines d'une science (Paris, 1921), p. 8. 12 Nicolas Malebranche, De la recherche de la verite (Paris, 1721), Ec1aircissement 11, 4: 277 ff. [The Search after Truth and Elucidations of the Search after Truth, trans. Thomas M. Lennon (Columbus: Ohio State University Press, 1980), p. 636 ff.] ; F. H. Bradley, Appearance and Reality (London, 1893), Ch. 11, p. 123 ff. 13 Stumpf quoted by Ernst Mach, Die Leitgedanken meiner Naturwissenschaftlichen Erkenntnislehre (Leipzig, 1919), p. 23. 14 Henri Marais, Introduction geometrique a l'etude de la relativite (Paris, 1923), p. 96. 15 Wien, WW 156, 220, 285; cf. 221,223, and our comments on Wien's comparison between the positions of Mach and Goethe (Ch. I, n. 6). Adolf Kneser similarly declares that "the quest for a real world cannot be dismissed," and that "the true evolution of science comes about in such a way that sensations are suppressed and fade away into insignificance" (Mathematik und Natur, Breslau, 1921, p. 31).