In speaking of empirio-criticism we could not avoid repeatedly mentioning the philosophers of the so-called immanentist school, the principal representatives of which are Schuppe, Leclair, Rehmke, and Schubert-Soldern. It is now necessary to examine the relation of empirio-criticism to the immanentists and the nature of the philosophy preached by the latter.
In 1902 Mach wrote: “. . . Today I see that a host of philosophers—positivists, empirio-criticists, adherents of the immanentist philosophy—as well as a very few scientists, have all, without knowing anything of each other, entered on new paths which, in spite of their individual differences, converge almost towards one point” (Analysis of Sensations, p. 9). Here we must first note Mach’s unusually frank admission that very few scientists are followers of the supposedly “new,” but in truth very old, Humean-Berkeleian philosophy. Secondly, extremely important is Mach’s opinion that this “new” philosophy is a broad current in which the immanentists are on the same footing as the empirio-criticists and the positivists. “Thus”—repeats Mach in the introduction to the Russian translation of the Analysis of Sensations (1906)—“there is a common movement. . .” (p. 4). “My position [Mach says in another place], moreover, borders closely on that of the representatives of the immanentist philosophy. . . . I found hardly anything in this book [i.e., W. Schuppe, Outline of the Theory of Knowledge and Logic] with which, with perhaps a very slight change, I would not gladly agree” (p. 46). Mach considers that Schubert-Soldern is also “following close paths” (p. 4), and as to Wilhelm Schuppe, Mach even dedicates to him his latest work, the summary so to speak of his philosophical labours, Knowledge and Error.
Avenarius, the other founder of empirio-criticism, wrote in 1894 that he was “gladdened” and “encouraged” by Schuppe’s sympathy for empirio-criticism, and that the “differences” between him and Schuppe “exist, perhaps, only temporarily” (vielleicht nur einstweilen noch bestehend). And, finally, J. Petzoldt, whose teachings Lessevich regards as the last word in empirio-criticism, openly acclaims the trio—Schuppe, Mach and Avenarius—as the leaders of the “new” trend. (Einführung in die Philosophie der reinen Erfahrung, Bd. II, 1904, S. 295; Das Weltproblem, 1906, S. v. und 146). On this point Petzoldt is definitely opposed to Willy (Einf., II, 321), probably the only outstanding Machian who felt ashamed of such a kinship as Schuppe’s and who tried to dissociate himself from him fundamentally, for which this disciple was reprimanded by his beloved teacher Avenarius. Avenarius wrote the words about Schuppe above quoted in a comment on Willy’s article against Schuppe, adding that Willy’s criticism perhaps “was put more strongly than was really necessary” (Vierteljahrsschrift für wissenschaftliche Philosophie, 18. Jahrg., 1894, S. 29; which also contains Willy’s article against Schuppe).
Having acquainted ourselves with the empirio-criticists’ opinion of the immanentists, let us examine the immanentists’ opinion of the empirio-criticists. We have already mentioned the opinion uttered by Leclair in 1879. Schubert-Soldern in 1882 explicitly expressed his “agreement” “in part with the elder Fichte” (i.e., the distinguished representative of subjective idealism, Johann Gottlieb Fichte, whose son was as inept in philosophy as was the son of Joseph Dietzgen), and “with Schuppe, Leclair, Avenarius and partly with Rehmke,” while Mach (Die Geschichte und die Wurzel des Satzes von der Erhaltung der Arbeit) is cited with particular gusto in opposition to “natural-historical metaphysics” —the term given to natural-historical materialism by all the reactionary university lecturers and professors in Germany. In 1893, after the appearance of Avenarius’ The Human Concept of the World, W. Schuppe hailed this work in An Open Letter to Prof. Avenarius as a “confirmation of the naïve realism” which he (Schuppe) himself advocated. “My conception of thought,” Schuppe wrote, “excellently harmonises with your [Avenarius’] pure experience.” Then, in 1896, Schubert-Soldern, summarising the “methodological trend in philosophy” on which he “bases himself,” traces his genealogy from Berkeley and Hume down through F. A. Lange (“the real beginning of our movement in Germany dates from Lange”), and then through Laas, Schuppe and Co., Avennrius and Mach, Riehl (among the Neo-Kantians), Ch. Renouvier (among the Frenchmen), etc. Finally, in their programmatic “Introduction” printed in the first issue of the philosophical organ of the immanentists, alongside a declaration of war on materialism and an expression of sympathy with Charles Renouvier, we read: “Even in the camp of the scientists themselves voices of individual thinkers are being raised sermonising against the growing arrogance of their colleagues, against the unphilosophical spirit which has taken possession of the natural sciences. Thus the physicist Mach. . . . On all hands fresh forces are stirring and are working to destroy the blind faith in the infallibility of the natural sciences, and once again people are beginning to seek for other paths into the profundities of the mysterious, a better entrance to the house of truth.”
A word or two about Ch. Renouvier. He is the head of the influential and widespread school in France known as the neo-criticists. His theoretical philosophy is a combination of the phenomenalism of Hume and the apriorism of Kant. The thing-in-itself is absolutely rejected. The connection of phenomena, order and law is declared to be a priori ; law is written with a capital letter and is converted into the basis of religion. The Catholic priests go into raptures over this philosophy. The Machian Willy scornfully refers to Renouvier as a “second apostle Paul,” as “an obscurantist of the first water” and as a “casuistic preacher of free will” (Gegen die Schulweisheit, S. 129). And it is such co-thinkers of the immanentists who warmly greet Mach’s philosophy. When his Mechanics appeared in a French translation, the organ of the neo-criticists—L’Année philosophique—edited by Pillon, a collaborator and disciple of Renouvier, wrote: “It is unnecessary to speak of the extent to which, in this criticism of substance, the thing, the thing-in-itself, Mach’s positive science agrees with neo-critical idealism” (Vol. XV, 1904, p. 179).
As for the Russian Machians, they are all ashamed of their kinship with the immanentists, and one of course could not expect anything else of people who did not deliberately adopt the path of Struve, Menshikov, and the like. Bazarov alone refers to “certain representatives of the immanentist school” as “realists.” Bogdanov briefly (and in fact falsely) declares that “the immanentist school is only an intermediate form between Kantianism and empirio-criticism” (Empirio-Monism, Bk. III, p. xxii). V. Chernov writes: “Generally speaking, the immanentists approach positivism in only one aspect of their theory, in other aspects they go far beyond it” (Philosophical and Sociological Studies, p. 37). Valentinov says that “the immanentist school clothed these [Machian] ideas in an unsuitable form and found themselves in the blind alley of solipsism” (op. cit., p. 149). As you see, you pay your money and take your choice: constitution and salmon mayonnaise, realism and solipsism. Our Machians are afraid to tell the plain and clear truth about the immanentists.
The fact is that the immanentists are rank reactionaries, I open advocates of fideism, unadulterated in their obscurantism. There is not one of them who has not frankly made his more theoretical works on epistemology a defence of religion and a justification of medievalism of one kind or another. Leclair, in 1879, advocated his philosophy as one that satisfies “all the needs of a religiously inclined mind” (Der Realismus, etc., S. 73). J. Rehmke, in 1880, dedicated his “theory of knowledge” to the Protestant pastor Biedermann and closed his book by preaching not a supersensible God, but God as a “real concept” (it was for this reason presumably, that Bazarov ranked “certain” immanentists among the “realists”?), and moreover the “objectivisation of this real concept is relegated to practical life,” while Biedermann’s “Christian dogmatism” is declared to be a model of “scientific theology” (J. Rehmke, Die Welt als Wahrnehmung und Begriff, Berlin, 1880, S. 312). Schuppe in the Zeitschrift für immanente Philosophie assures us that though the immanentists deny the transcendental, God and the future life do not come under this concept (Zeitschrift für immanente Philosophie, II. Band, S. 52). In his Ethik he insists on the “connection of the moral law . . . with the metaphysical world conception” and condemns the separation of the church from the state as a “senseless phrase” (Dr. Wilhelm Schuppe, Grundzüge der Ethik und Rechtsphilosophie [Principles of Ethics and the Philosophy of Law], Breslau, 1881, S. 181, 325). Schubert-Soldern in his Foundations of the Theory of Cognition deduces both the pre-existence of the self before the body and the after-existence of the self after the body, i.e.,the immortality of the soul (op. cit., p. 82), etc. In The Social Question, arguing against Bebel, he defends, together with “social reforms,” suffrage based on class distinction, and says that the “Social-Democrats ignore the fact that without the divine gift of unhappiness there could be no happiness” (p. 330), and thereupon laments the fact that materialism “prevails” (p. 242): “he who in our time believes in a life beyond, or even in its possibility, is considered a fool” (ibid.).
And German Menshikovs like these, no less obscurantists of the first water than Renouvier, live in lasting concubinage with the empirio-criticists. Their theoretical kinship is in contestable. There is no more Kantianism in the immanentists than in Petzoldt or Pearson. We saw above that they themselves regard themselves as disciples of Hume and Berkeley, an opinion of the immanentists that is generally recognised in philosophical literature. In order to show clearly what epistemological premises these comrades-in-arms of Mach and Avenarius proceed from, we shall quote some fundamental theoretical propositions from the works of immanentists.
Leclair in 1879 had not yet invented the term “immanent,” which really signifies “experiential,” “given in experience,” and which is just as spurious a label for concealing corruption as the labels of the European bourgeois parties. In his first work, Leclair frankly and explicitly calls himself a “critical idealist” (Der Realismus, etc., S. 11, 21, 206, etc.). In this work he criticises Kant, as we have already seen, for his concessions to materialism, and clearly indicates his wn path away from Kant to Fichte and Berkeley. Leclair fights materialism in general and the tendency towards materialism displayed by the majority of scientists in particular as mercilessly as Schuppe, Schubert-Soldern and Rehmke.
“If we return,” Leclair says, “to the standpoint of critical idealism, if we do not attribute a transcendental existence [i.e., an existence outside of human consciousness] to nature or the processes of nature, then for the subject the aggregate of bodies and his own body, in so far as he can see and feel it, together with all its changes, will be a directly given phenomenon of spatially connected co-existences and successions in time, and the whole explanation of nature will reduce itself to stating the laws of these co-existences and successions” (p. 21).
Back to Kant!—said the reactionary Neo-Kantians. Back to Fichte and Berkeley!—is essentially what the reactionary immanentists are saying. For Leclair, all that exists consists of “complexes of sensations” (p. 38), while certain classes of properties (Eigenschaften), which act upon our sense-organs, he designates, for example, by the letter M, and other classes, which act upon other objects of nature, by the letter N (p. 150, etc.). Moreover, Leclair speaks of nature as the “phenomena of the consciousness” (Bewusstseinsphänomen) not of a single person, but of “mankind” (pp. 55-56). If we remember that Leclair published his book in Prague, where Mach was professor of physics, and that Leclair cites with rapture only Mach’s Erhaltung der Arbeit, which appeared in 1872, the question involuntarily arises: ought we not to regard the advocate of fideism and frank idealist Leclair as the true progenitor of the “original” philosophy of Mach?
As for Schuppe, who, according to Leclair, arrived at the “same results,” he, as we have seen, really claims to defend “naïve realism,” and in his Open Letter to Prof. Avenarius bitterly complains of the “established perversion of my [Schuppe’s] theory of knowledge to subjective idealism.” The true nature of the crude forgery which the immanentist Schuppe calls a defence of realism is quite clear from his rejoinder to Wundt, who did not hesitate to class the immanentists with the Fichteans, the subjective idealists (Philosophische Studien, loc. cit., S. 386, 397, 407).
“In my case,” Schuppe retorts to Wundt, “the proposition ‘being is consciousness’ means that consciousness without the external world is inconceivable, that the latter belongs to the former, i.e.,the absolute connection (Zusammengehörigkeit) of the one with the other, which I have so often asserted and explained and in which the two constitute the primary whole of being.”
One must be extremely naïve not to discern unadulterated subjective idealism in such “realism”! Just think: the external world “belongs to consciousness” and is in absolute connection with it! The poor professor was indeed slandered by the “established” practice of ranking him with the subjective idealists! Such a philosophy completely coincides with Avenarius’ “principal co-ordination”; no reservations and protests on the part of Chernov and Valentinov can sunder them; both philosophies will be consigned together to the museum of reactionary fabrications of German professordom. As a curiosity once more testifying to Valentinov’s lack of judgment, let us note that he calls Schuppe a solipsist (it goes without saying that Schuppe vowed and swore that he was not a solipsist—and wrote special articles to this effect—just as vehemently as did Mach, Petzoldt, and Co.), yet is highly delighted with Bazarov’s article in the Studies ! I should like to translate into German Bazarov’s dictum that “sense-perception is the reality existing outside us” and forward it to some more or less intelligent immanentist. He would embrace and kiss Bazarov as heartily as the Schuppes, Leclairs and Schubert-Solderns embraced Mach and Avenarius. For Bazarov’s dictum is the alpha and omega of the doctrines of the immanentist school.
And here, lastly, is Schubert-Soldern. “The materialism of natural science,” the “metaphysics” of recognising the objective reality of the external world, is the chief enemy of this philosopher (Grundlagen einer Erkenntnistheorie, 1884, p. 31 and the whole of Chapter II: “The Metaphysics of Natural Science”). “Natural science abstracts from all relations of consciousness” (p. 52)—that is the chief evil (and that is just what constitutes materialism!). For the individual cannot escape from “sensations and, hence, from a state of consciousness” (pp. 33-34). Of course, Schubert-Soldern admitted in 1896, my standpoint is epistemological solipsism (Die soziale Frage, S. x), but not “metaphysical,” not “practical” solipsism. “What is given us immediately is sensations, complexes of constantly changing sensations” (Ueber Transcendenz des Objekts und Subjekts, S. 73).
“Marx took the material process of production,” says Schubert-Soldern, “as the cause of inner processes and motives, in the same way (and just as falsely) as natural science regards the common [to humanity] external world as the cause of the individual inner worlds” (Die soziale Frage, S. xviii). That Marx’s historical materialism is connected with natural-historical materialism and philosophical materialism in general, it does not even occur to this comrade in-arms of Mach to doubt.
“Many, perhaps the majority, will be of the opinion that from the standpoint of epistemological solipsism no metaphysics is possible, i.e.,that metaphysics is always transcendental. Upon more mature reflection I cannot concur with this opinion. Here are my reasons. . . . The immediate foundation of all that is given is the spiritual (solipsist) connection, the central point of which is the individual self (the individual realm of thought) with its body. The rest of the world is inconceivable without this self, just as this self is inconceivable without the rest of the world. With the destruction of the individual self the world is also annihilated, which appears impossible—and with the destruction of the rest of the world, nothing remains for my individual self, for the latter can be separated from the world only logically, but not in time and space. Therefore my individual self must continue to exist after my death also, if the entire world is not to be annihilated with it. . .” (ibid., p. xxiii).
The “principal co-ordination,” “complexes of sensations” and the rest of the Machian banalities render faithful service to the proper people!
“. . . What is the hereafter (das Jenseits) from the solipsist point of view? It is only a possible future experience for me. . .” (ibid.). “Spiritualism . . . would be obliged to prove the existence of the Jenseits. But at any rate the materialism of natural science cannot be brought into the field against spiritualism, for this materialism, as we have seen, is only one aspect of the world process within the all-embracing spiritual connection” ( = the “principal co-ordination”) (p. xxiv).
All this is said in that philosophical introduction to Die soziale Frage (1896) wherein Schubert-Soldern all the time appears arm in arm with Mach and Avenarius. Only for the handful of Russian Machians does Machism serve exclusively for purposes of intellectual prattle. In its native country its role as a flunkey to fideism is openly proclaimed!
 Vierteljahrsschrift für wissenschaftliche Philosophie, 1894, 18. Jahrg., Heft I, S. 29. —Lenin
 Dr. Richard von Schubert-Soldern, Ueber Transcendenz des Objekts und Subjekts [On the Transcendence of the Object and Subject], 1882, S. 37 and 5. Cf. also his Grundlagen einer Erkenntnistheorie [Principles of a Theory of Knowledge], 1884, S. 3. —Lenin
 Vierteijahrsschlift für wissenschaftliche Philosophie, 17. Jahrg., 1893, S. 384. —Lenin
 Dr. Richard von Schubert-Soldern, Das menschliche Glück und die soziale Frage [Human Happiness and the Social Question], 1896, S. v, vi. —Lenin
 Zeitschrift für immanente Philosophie, Bd. I, Berlin, 1896, S. 6, 9. —Lenin
 “Realists in modern philosophy—certain representatives of the immanentist school who have emerged from Kantianism, the school of Mach-Avenarius, and many other kindred movements—find that there are absolutely no grounds for rejecting the basis of naïve realism” (Studies, etc., p. 26). —Lenin
 Schubert-Soldern, Grundlage einer Erkenntnistheorie.—Ed.
 Die soziale Frage.—Ed.
 Beiträge zu einer monistischen Erkenntnistheorie [Essays in a Monistic Theory of Knowledge], Breslau, 1882, S. 10. —Lenin
 Wilhelm Schuppe, “Die immanente Philosophie und Wilhelm Wundt” [“The Immanent Philosophy and Wilhelm Wundt”] Zeitschrift für immanente Philosophie, Band II, S. 195. —Lenin
 Zeitschrift für immanente Philosophia (Journal for Immmanentist Philosophy)—a German reactionary journal, published in Berlin from 1895 to 1900 under the editorship of M. B. Kauffmann, with the participation of Wilhelm Schuppe and Richard von Schubert Soldern. p. 211
 L’Année philosophique (The Philosophical Year,)—the organ of the French “neo-criticists”, published in Paris from 1890 to 1913 under the editorship of F. Pillon. p. 212