As a supplement to what has been said above of the idealists as the comrades-in-arms and successors of empirio-criticism, it will be appropriate to dwell on the character of the Machian criticism of certain philosophical propositions touched upon in our literature. For instance, our Machian would-be Marxists fastened with glee on Plekhanov’s “hieroglyphs,” that is, on the theory that man’s sensations and ideas are not copies of real things and processes of nature, not their images, but conventional signs, symbols, hieroglyphs, and so on. Bazarov ridicules this hieroglyphic materialism; and, it should be stated, he would be right in doing so if he rejected hieroglyphic materialism in favour of non-hieroglyphic materialism. But Bazarov here again resorts to a sleight-of-hand and palms off his renunciation of materialism as a criticism of “hieroglyphism.” Engels speaks neither of symbols nor of hieroglyphs, but of copies, photographs, images, mirror-reflections of things. Instead of pointing out the erroneousness of Plekhanov’s deviation from Engels’ formulation of materialism, Bazarov uses Plekhanov’s error in order to conceal Engels’ truth from the reader.
To make clear both Plekhanov’s error and Bazarov’s confusion we shall refer to an important advocate of the “theory of symbols” (calling a symbol a hieroglyph changes nothing), Helmholtz, and shall see how he was criticised by the materialists and by the idealists in conjunction with the Machians.
Helmholtz, a scientist of the first magnitude, was as inconsistent in philosophy as are the great majority of scientists. He tended towards Kantianism, but in his epistemology he did not adhere even to these views consistently. Here for instance are some passages on the subject of the correspondance of ideas and objects from his Handbook of Physiological Optics: “I have . . . designated sensations as merely symbols for the relations of the external world and I have denied that they have any similarity or equivalence to what they represent” (French translation, p. 579; German original, p. 442). This is agnosticism, but on the same further on we read: “Our concepts and ideas are effects wrought on our nervous system and our consciousness by the objects that are perceived and apprehended.” This is materialism. But Helmholtz is not clear as to the relation between absolute and relative truth, as is evident from his subsequent remarks. For instances, a little further on he says: “I therefore think that there can be no possible meaning in speaking of the truth of our ideas save as a practical truth. Our ideas of things cannot be anything but symbols, naturally given signs for things, which we learn to use in order to regulate our movements and actions. When we have learned to read these symbols rightly we are in a position with their aid to direct our actions so as to achieve the desired result...” This is not correct. Helmholtz here lapses into subjectivism, into a denial of objective reality and objective truth. And he arrives at a flagrant untruth when he concludes the paragraph with the words: “An idea and the object it represents obviously belong to two entirely different worlds....” Only the Kantians thus divorce idea from reality, consciousness from nature. However, a little further on we read: “As to the properties of the objects of the external world, a little reflection will show that all the properties we may attribute to them merely signify the effects wrought by them either on our senses or on other natural objects” (French ed., p. 581; German original, p. 445; I translate from the French). Here again Helmholtz reverts to the materialist position. Helmholtz was an inconsistent Kantian, now recognising a priori laws of thought, now tending towards the “transcendental reality” of time and space (i.e., to a materialist conception of them); now deriving human sensations from external objects, which act upon our sense organs, and now declaring sensations to be only symbols, i.e.,certain arbitrary signs divorced from the “entirely different” world of the things signified (cf. Viktor Heyfelder, Ueber den Begriff der Erfahrung bei Helmholtz [Helmholtz’s Conception of Experience], Berlin 1897).
This is how Helmholtz expressed his views in a speech delivered in 1878 on “Facts in Perception” (“a noteworthy pronouncement from the realistic camp,” as Leclair characterised this speech): “Our sensations are indeed effects wrought by external causes in our organs, and the manner in which such effects manifest themselves, of course, depends very essentially on the nature of the apparatus on which these effects are wrought. Inasmuch as the quality of our sensation informs us of the properties of the external action by which this sensation is produced, the latter can be regarded as its sign (Zeichen), but not as its image. For a certain resemblance to the object imaged is demanded of an image. . . . But a sign need not resemble that of which it is a sign. . .” (Vorträge und Reden [Lectures and Speeches], 1884, Bd. II, S. 226). If sensations are not images of things, but only signs or symbols which do “not resemble” them, then Helmholtz’s initial materialist premise is undermined; the existence of external objects becomes subject to doubt; for signs or symbols may quite possibly indicate imaginary objects, and everybody is familiar with instances of such signs or symbols. Helmholtz, following Kant, attempts to draw something like an absolute boundary between the “phenomenon” and the “thing-in itself.” Helmholtz harbours an insuperable prejudice against straightforward, clear, and open materialism. But a little further on he says: “I do not see how one could refute a system even of the most extreme subjective idealism that chose to regard life as a dream. One might declare it to be highly improbable and unsatisfactory—I myself would in this case subscribe to the severest expressions of dissent—yet it could be constructed consistently. . . . The realistic hypothesis, on the contrary, trusts the evidence (Aussage) of ordinary self-observation, according to which the changes of perception that follow a certain action have no psychical connection with the preceding impulse of volition. This hypothesis regards everything that seems to be substantiated by our everyday perception, viz., the material world outside of us, as existing independently of our ideas.” (pp. 242-43.) “Undoubtedly, the realistic hypothesis is the simplest we can construct; it has been tested and verified in an extremely broad field of application; it is sharply defined in its several parts and, therefore, it is in the highest degree useful and fruitful as a basis of action” (p. 243). Helmholtz’s agnosticism also resembles “shamefaced materialism,” with certain Kantian twists, in distinction to Huxley’s Berkeleian twists.
Albrecht Rau, a follower of Feuerbach, therefore vigorously criticises Helmholtz’s theory of symbols as an inconsistent deviation from “realism.” Helmholtz’s basic view, says Rau, is a realistic hypothesis, according to which “we apprehend the objective properties of things with the help of our senses”. The theory of symbols cannot be reconciled with such a view (which, as we have seen, is wholly materialist), for it implies a certain distrust of perception, a distrust of the evidence of our sense-organs. It is beyond doubt that an image cannot wholly resemble the model, but an image is one thing, a symbol, a conventional sign, another. The image inevitably and of necessity implies the objective reality of that which it “images.” “Conventional sign,” symbol, hieroglyph are concepts which introduce an entirely unnecessary element of agnosticism. Albrecht Rau, therefore, is perfectly right in saying that Helmholtz’s theory of symbols pays tribute to Kantianism. “Had Helmholtz,” says Rau, “remained true to his realistic conception, had he consistently adhered to the basic principle that the properties of bodies express the relations of bodies to each other and also to us, he obviously would have had no need of the whole theory of symbols; he could then have said, briefly and clearly: the sensations which are produced in us by things are reflections of the nature of those things” (ibid., p. 320).
That is the way a materialist criticises Helmholtz. He rejects Helmholtz’s hieroglyphic or symbolic materialism or semi-materialism in favour of Feuerbach’s consistent materialism.
The idealist Leclair (a representative of the “immanentist school,” so dear to Mach’s heart and mind) also accuses Helmholtz of inconsistency, of wavering between materialism and spiritualism. (Der Realismus, etc., S. 154.) But for Leclair the theory of symbols is not insufficiently materialistic but too materialistic. Leclair says: “Helmholtz thinks that the perceptions of our consciousness offer sufficient support for the cognition of sequence in time as well as of the identity or non-identity of transcendental causes. This in Helmholtz’s opinion is sufficient for the assumption and cognition of law in the realm of the transcendental” (i.e., in the realm of the objectively real) (p. 33). And Leclair thunders against this “dogmatic prejudice of Helmholtz’s”: “Berkeley’s God,” he exclaims, “as the hypothetical cause of the conformity to natural law of the ideas in our mind is at least just as capable of satisfying our need of causality as a world of external objects” (p. 31). “A consistent application of the theory of symbols. . . can achieve nothing without a generous admixture of vulgar realism” (i.e., materialism) (p. 35).
This is how a “critical idealist” criticised Helmholtz for his materialism in 1879. Twenty years later, in his article “The Fundamental Views of Ernst Mach and Heinrich Hertz on Physics,” Kleinpeter, the disciple of Mach so highly praised by his teacher, refuted in the following way the “antiquated” Helmholtz with the aid of Mach’s “recent” philosophy. Let us for the moment leave aside Hertz (who, in fact, was as inconsistent as Helmholtz) and examine Kleinpeter’s comparison of Mach and Helmholtz. Having quoted a number of passages from the works of both writers, and having particularly stressed Mach’s well-known statements to the effect that bodies are mental symbols for complexes of sensations and so on, Kleinpeter says:
“If we follow Helmholtz’s line of thought, we shall encounter the following fundamental premises:
“1) There exist objects of the external world.
“2) A change in these objects is inconceivable without the action of some cause (which is thought of as real).
“3) ‘Cause, according to the original meaning of the word, is the unchangeable residue or being behind the changing phenomena, namely, substance and the law of its action, force.’ [The quotation is taken by Kleinpeter from Helmholtz.]
“4)It is possible to deduce all phenomena from their causes in a logically strict and uniquely determined manner.
“5)The achievement of this end is equivalent to the possession of objective truth, the acquisition (Erlangung) of which is thus regarded as conceivable” (p. 163).
Rendered indignant by these premises, by their contradictoriness and their creation of insoluble problems, Kleinpeter remarks that Helmholtz does not hold strictly to these views and sometimes employs “turns of speech which are somewhat suggestive of Mach’s purely logical understanding of such words” as matter, force, causality, etc.
“It is not difficult to find the source of our dissatisfaction with Helmholtz, if we recall Mach’s fine, clear words. The false understanding of the words mass, force, etc., is the basic weakness of Helmholtz’s whole argument. These are only concepts, products of our imagination and not realities existing outside of thought. We are not even in a position to know such things. From the observation of our senses we are in general unable, owing to their imperfection, to make even a single uniquely determined conclusion. We can never assert, for instance, that upon reading a certain scale (durch Ablesen einer Skala) we shall obtain a definite figure: there are always, within certain limits, an infinite number of possible figures all equally compatible with the facts of the observation. And to have knowledge of something real lying outside us—that is for us impossible. Let us assume, however, that it were possible, and that we did get to know reality; in that case we would have no right to apply the laws of logic to it, for they are our laws, applicable only to our conceptions, to our mental products [Kleinpeter’s italics]. Between facts there is no logical connection, but only a simple succession; apodictic assertions are here unthinkable. It is therefore incorrect to say that one fact is the cause of another and, consequently, the whole deduction built up by Helmholtz on this conception falls to the ground. Finally, the attainment of objective truth, i.e.,truth existing independently of any subject, is impossible, not only because of the nature of our senses, but also because as men (als Menschen) we can in general have no notion of what exists quite independently of us (p. 164).
As the reader sees, our disciple of Mach, repeating the favourite phrases of his teacher and of Bogdanov, who does not own himself a Machian, rejects Helmholtz’s whole philosophy, rejects it from the idealist standpoint. The theory of symbols is not even especially singled out by the idealist, who regards it as an unimportant and perhaps accidental deviation from materialism. And Helmholtz is chosen by Kleinpeter as a representative of the “traditional views in physics,” “views shared to this day by the majority of phys icists” (p. 160).
The result we have arrived at is that Plekhanov was guilty of an obvious mistake in his exposition of materialism, but that Bazarov completely muddled the matter, mixed up materialism with idealism and advanced in opposition to the “theory of symbols,” or “hieroglyphic materialism,” the idealist nonsense that “sense-perception is the reality existing out side us.” From the Kantian Helmholtz, just as from Kant himself, the materialists went to the Left, the Machians to the Right.
 Helmholtz, Handbuch der physiologischen Optik.—Ed.
 Albrecht Rau, Empfinden und Denken [Sensation and Thought], Giessen, 1896, S. 304. —Lenin
 Archiv für Philosophie, II, Systematische Philosophie, Bd. V., 1899, S. 163-64. —Lenin
 In Geneva in 1892 appeared the first Russian edition of Engels’ work Ludwig Feuerbach and the End of Classical German Philosophy, translated by G. V. Plokhanov and with a foreword and notes by him. Commenting on Engels’ formulation of the fundamental question of philosophy and characterisation of agnosticism, Plekhanov gave a critical exposition of the theory of knowledge of a number of trends of idealist philosophy (Hume, Kant, the neo-Kantians, etc.) and counterposed to them the materialist theory of knowledge, in doing so he committed an error by saying:
“Our sensations are in their way hieroglyphs which inform us of what is taking place in reality. The hieroglyphs do not resemble the events convoyed by them. But they can with complete fidelity convey both the events themselves, and—what is the main thing—the relations existing between them” (G. V. Plekhanov, Selected Philosophical Works, Vol. 1, Moscow, p. 536). In 1905, in the notes to the second edition of Engels’ work, Plekhanov admitted: “I also failed to express myself quite exactly” (ibid., p. 545). Plekhanov’s error, although appearing to be a question of terminology, was a concession to agnosticism and bore witness to his insufficiently profound understanding of the dialectics of the process of cognition.
 Archiv für Philosophie (Philosophical Archives)—a German philosophical journal of an idealist tendency, organ of the neo-Kantians and Machists. It was published in Berlin from 1895 to 1931 in two parallel editions: the first, entitled Archiv für Geschichte der Philosophie (Archives of the History of Philosophy) was edited by L. Stein; the second, entitled Archiv für systemsatische Philosaphic (Archives of Systematic Philosophy), was edited by Paul Natorp. From 1925 the journal appeared under the title of Archiv für systematische Philosophie und Soziologic (Archives of Systematic Philosophy and Sociology).