In the later part of the 19th century, middle-class society  turned away more and more from materialism. The bourgeoisie, through the development of capitalism, asserted its social mastery; but the rise of the working-class movements proclaiming as its aim the annihilation of capitalism, led to misgivings as to the durability of the existing social system. World and future appeared full of unsolvable problems. Since the visible, material forces threatened mischief, the ruling class, to quiet its apprehensions and assure its self-reliance, turned to the belief in the superior rule of spiritual powers. Mysticism and religion gained the upper hand, and still more so in the 20th century, after the First World War.
Natural scientists form a part of middle-class society; they are in continual contact with the bourgeoisie and are influenced by its spiritual trends. At the same time, through the progress of science, they have to deal with new problems and contradictions appearing in their concepts. It is not clear philosophical insight that inspires the criticism of their theories, but rather the immediate needs of their practical study of nature. This criticism then takes its form and colour from the anti-materialist trends in the ruling class. Thus modern natural philosophy exhibits two characters: critical reflection over the principles of science, and a critical mood towards materialism. Just as in the time of Hegel, valuable progress in the theory of knowledge is garbed in mystical and idealistic forms.
Critics of the prevailing theories came forward, in the last part of the 19th century, in different countries: e.g. Karl Pearson in England, Gustav Kirchhoff and Ernst Mach in Germany, Henri Poincaré in France, all exhibiting, though in different ways, the same general trend of thought. Among them the writings of Mach have doubtless exerted the greatest influence upon the ideas of the next generation.
Physics, he says, should not proceed from matter, from the atoms, from the objects; these are all derived concepts. The only thing we know directly is experience, and all experience consists in sensations, sense impressions (Empfindungen). By means of our world of concepts, in consequence of education and intuitive custom, we express every sensation as the action of an object upon ourselves as subject: I see a stone. But freeing ourselves from this custom we perceive that a sensation is a unit in itself, given directly without the distinction of subject and object. Through a number of similar sensations I come to the distinction of an object, and I know of myself too only by a totality of such sensations. Since object and subject are built up of sensations it is better not to use a name that points to a person experiencing them. So we prefer the neutral name of “elements”, as the simplest basis of all knowledge.
Ordinary thinking here finds the paradox that the hard immutable stone, the prototype of the solid “thing” should be formed by, should “consist of” such transient subjective stuff as sensations. On closer examination, however, we see that what constitutes the thing, its qualities, are simply this and nothing else. First its hardness is nothing but the totality of a number of often painful sensations; and secondly its immutability is the sum total of our experiences that on our returning to the same spot the same sensations repeat themselves. So we expect them as a fixed interconnection in our sensations. In our knowledge of the thing there is nothing that has not somehow the character of a sensation. The object is the sum total of all sensations at different times that, through a certain constancy of place and surroundings considered as related, are combined and denoted by a name. It is no more; there is no reason to assume with Kant a “thing in itself” (Ding an sich) beyond this sensation-mass; we cannot even express in words what we would have to think of it. So the object is formed entirely by sensations; it consists merely of sensations. Mach opposes his views to the current physical theory by the words:
“Not bodies produce sensations, but element-complexes (sensation-complexes) constitute the bodies. When the physicist considers the bodies as the permanent reality, the ‘elements’ as the transient appearance, he does not realise that all ‘bodies’ are only mental symbols for element-complexes (sensation-complexes)” (Analyse der Empfindungen, p.23).
The same holds for the subject. What we denote by “I myself” is a complex of recollections and feelings, former and present sensations and thoughts connected by continuity of memory, bound to a special body, but only partly permanent.
“What is primary is not myself but the elements ... The elements constitute the myself ... The elements of consciousness of one person are strongly connected, those of different persons are only weakly and passingly connected. Hence everybody thinks he knows only of himself as an indivisible and independent unity” (Analyse der Empfindungen, p.19).
In his work Die Mechanik in ihrer Entwicklung (1883) (The Development of Mechanics) he writes along the same lines:
“Nature consists of the elements given by the senses. Primitive man first takes out of them certain complexes of these elements that present themselves with a certain stability and are most important to him. The first and oldest words are names for ‘things’. Here abstraction is made from the surroundings, from the continual small changes of these complexes, which are not heeded because they are not important. In nature there is no invariable thing. The thing is an abstraction, the name is a symbol for a complex of elements of which we neglect the changes. That we denote the entire complex by one word, one symbol, is done because we want to awaken at once all impressions that belong together.... The sensations are no ‘symbols of things’. On the contrary the ‘thing’ is a mental symbol for a sensation-complex of relative stability. Not the things, the bodies, but colours, sounds, pressures, times (what we usually call sensations) are the true elements of the world. The entire process has an economical meaning. In picturing facts we begin with the ordinary more stable and habitual complexes, and afterwards for correction add what is unusual” (p.454).
In this treatment of the historical development of the science of mechanics he comes close to the method of Historical Materialism. To him the history of science is not a sequence of geniuses producing marvellous discoveries. He shows how the practical problems are first solved by the mental methods of common life, until at last they acquire their most simple and adequate theoretical expression. Ever again the economic function of science is emphasised.
“The aim of all science is to substitute and to save experiences through the picturing and the forecastings of facts by thoughts, because these pictures are more easily at hand than the experiences themselves and in many respects may stand for them” (p. 452). “When we depict facts by thoughts we never imitate them exactly, but only figure those sides that are important for us; we have an aim that directly or indirectly arose out of practical interests. Our pictures are always abstractions. This again shows am economic trend” (p.454).
Here we see science, specialised as well as common knowledge, connected with the necessities of life, as an implement of existence.
“The biological task of science is to offer a most perfect orientation to man in the full possession of his senses” (Analyse der Empfindungen, p.29).
For man, in order to react efficiently to the impressions of his surroundings in each situation, it is not necessary to remember all former cases of analogous situations with their results. He has only to know what results generally, as a rule, and this determines his actions. The rule, the abstract concept is the instrument ready at hand that saves the mental consideration of all former cases. What natural law states is not what will happen and must happen in nature, but what we expect will happen; and that is the very purpose they have to serve.
The formation of abstract concepts, of rules and laws of nature, in common life as well as in science, is an intuitive process, intended to save brain work, aiming at economy of thinking. Mach shows in a number of examples in the history of science how every progress consists in greater economy, in that a larger field of experiences is compiled in a shorter way, so that in the predictions a repetition of the same brain operations is avoided. “With the short lifetime of man and ms limited memory, notably knowledge is only attainable by the utmost economy of thinking.” So the task of science consists in “representing facts as completely as possible by a minimum of brainwork” (Die Mechanik in ihrer Entwicklung, p.461).
According to Mach the principle of economy of thinking determines the character of scientific investigation. What science states as properties of things and laws about atoms are in reality relations between sensations. The phenomena between which the law of gravitation establishes relations, consist in a number of visual auditory or tactile impressions; the law says that they occur not by chance, and predicts how we may expect them. Of course we cannot express the law in this form; it would be inappropriate, unsuitable to practice because of its complexity. But as a principle, it is important to state that every law of nature deals with relations between phenomena. If now contradictions appear in our conceptions about atoms and world ether, they lie not in nature but in the forms we choose for our abstractions in order to have them available in the most tractable way. The contradiction disappears when we express the results of our research as relations between observed quantities, ultimately between sensations.
The unconcerned scientific view is easily obscured if a point of view fit for a limited aim is made the basis of all considerations. This is the case, says Mach, “when all experiences are considered as the effects of an outer world upon our consciousness. An apparently inextricable tangle of metaphysical difficulties results. The phantom disappears directly if we take matters in their mathematical form, and make it clear to ourselves that the establishment of functions and relations alone avails, and that the mutual dependence of experiences is the only thing we wish to know” (Analyse der Empfindungen, p.28). It might seem that Mach here expresses some doubts about the existence of an outer world independent of man. In countless other sentences, however, he speaks in a clear way of surrounding nature in which we have to live and which we have to investigate. It means that such an outer world as is accepted by physics and by ordinary opinion, the world of matter and forces as producing the phenomena, leads us into contradictions. The contradictions can be removed only if we return to the phenomena and instead of speaking words and abstract terms express our results as relations between observations. This is what was afterwards called Mach’s principle: if we ask whether a statement has a meaning and what is its meaning, we have to look for what experiments may test it. It has shown its importance in modern times, first in discussions on time and space in the theory of relativity, and then in the understanding of atomic and radiation phenomena. Mach’s aim was to find a broader field of interpretation for physical phenomena. In daily life the solid bodies are most adequate sensation-complexes, and mechanics, the science of their motions, was the first well developed part of physics. But this reason does not justify our establishing the form and science of atoms as the pattern for the entire world. Instead of explaining heat, light, electricity, chemistry, biology, all in terms of such small particles, every realm should develop its own adequate concepts.
Yet there is a certain ambiguity in Mach’s expressions on the outer world, revealing a manifest propensity towards subjectivism, corresponding to the general mystical trend in the capitalist world. Especially in later years he liked to discover cognate trends everywhere, and gave praise to idealistic philosophies that deny the reality of matter. Mach did not elaborate his views into a concise coherent system of philosophy with all consequences well developed. His aim was to give critical thoughts, to stimulate new ideas, often in paradoxes sharply pointed against prevailing opinions, without caring whether all his statements were mutually consistent and all problems solved. His was not a philosopher’s mind constructing a system, but a scientist’s mind, presenting his ideas as a partial contribution to the whole, feeling as part of a collectivity of investigators, sure that others will correct his errors and will complete what he left unachieved. “The supreme philosophy of a natural scientist” he says elsewhere “is to be content with an incomplete world view and to prefer it to an apparently complete but unsatisfactory system” (Die Mechanik in ihrer Entwicklung, p.437).
Mach’s tendency to emphasise the subjective side of experience appears in that the immediately given elements of the world, which we call phenomena, are denoted as sensations. Surely this means at the same time a deeper analysis of the phenomena; in the phenomenon that a stone falls are contained a number of visual sensations combined with the memory of former visual and spatial sensations. Mach’s elements, the sensations, may be called the simplest constituents of the phenomena. But when he says: “Thus it is true that the world consists of our sensations” (Analyse der Empfindungen, p.10) he means to point to the subjective character of the elements of the world. He does not say “my” sensations; solipsism (the doctrine that I myself only am existing) is entirely foreign to him and is expressly refuted; “I myself” is itself a complex of sensations. But where he speaks of fellow-men in relation to the world of sensations, he is not entirely clear.
“Just as little as I consider red and green as belonging to an individual body, so little I make an essential difference – from this point of view of general orientation – between my sensations and another’s sensations. The same elements are mutually connected in many ‘myselfs’ as their nodal points. These nodal points, however, are nothing perennial, they arise and disappear and change continually” (Analyse der Empfindungen, p.294).
Here it must be objected that “red” and “green” as belonging to more bodies are not the simple sensational elements of experience, but themselves already abstract concepts. It seems that Mach here replaces the abstract concepts body and matter by other abstract concepts, qualities and colours, that as realities appear in my and in another’s sensations. And when he calls my sensation and another’s analogous sensation the same element, this word is taken in another sense.
Mach’s thesis that the world consists of our sensations, expresses the truth that we knew of the world only through our sensations; they are the materials out of which we build our world; in this sense the world, including myself, “consists” of sensations only. At the same time, the emphasis upon the subjective character of sensations reveals the same middle-class trend of thought that we mind in other contemporary philosophies. It is even more evident when he points out that these views may tend to overcome dualism, this eternal philosophical antithesis of the two worlds of matter and mind. The physical and the psychical world for Mach consist of the same elements, only in a different arrangement. The sensation green in seeing a leaf, with other sensations is an element of the material leaf; the same sensation, with others of my body, my eye, my reminiscences, is an element of “myself,” of my psyche.
“Thus I see no antithesis of the physical and the psychical, but I see a simple identity relative to these elements. In the sensual realm of my consciousness every object is physical and psychical at the same time” (Analyse der Empfindungen, p36). “Not the stuff is different in both realms, but the tendency of the research” (p.14).
Thus dualism has disappeared; the entire world is a unity, consisting of the self-same elements; and these elements are not atoms but sensations. And in Erkenntnis und Irrtum he adds in a footnote
“There is no difficulty in building up every physical happening out of sensations, i.e. psychical elements; but there is no possibility of seeing how out of the usual physical elements, masses and motions, any psychical happening might be constructed ... We have to consider that nothing can be object of experience or science that cannot be in some way a part of consciousness” (p.12).
Here, in this footnote added later, in 1905, the well considered equivalence of both worlds, physical and psychical, the careful neutral characterising of the elements, is given up by calling them psychical, and the anti-materialistic spirit of the bourgeoisie breaks through. Since it is not our aim to criticise and to contest but only to set forth Mach’s views we shall not enter into the tautology of the last sentence, that only what is in consciousness can be conscious and that hence the world is spiritual.
The new insight that the world is built up out of sensations as its elements, meets with difficulties, Mach says, because in our uncritical youth we took over a world view that had grown intuitively in the thousands of years of human development. We may break its spell by critically repeating the process through conscious philosophic reasoning. Starting with the most simple experiences, the elementary sensations, we construct the world step by step: ourselves, the outer world, our body as part of the outer world, connected with our own feeling, actions and reminiscences. Thus, by analogy, we recognise fellow-men as kindred, and so their sensations, disclosed by their sayings, may be used as additional material in constructing the world. Here Mach stops; further steps toward an objective world are not made.
That this is no accidental incompleteness is shown by the fact that we find the same thing with Carnap, one of the leading thinkers in modern philosophy of science. In his work Der logische Aufbau der Welt (The logical construction of the world) he sets himself the same task, but more thoroughly: if we start with knowing nothing, having however our full capacity of thinking, how can we establish (“constitute”) the world with all its contents? I start with “my sensations” and make them into a system of “sayings” and “objects” (“object” is the name given to everything about which we may utter a saying); thus I establish physical and psychical “objects” and construct “the world” as an ordered system of my sensations. The problem of dualism of body and mind, of material and spiritual, finds here the same answer as with Mach: both consist of the same materials, the sensations, only ordered in a different way. The sensations of fellow-men, according to their statements, lead to a physical world exactly corresponding to mine. So we call it the “intersubjective world,” common to all subjects; this is the world of natural science. Here Carnap stops, satisfied that dualism has been removed, and that any quest about the reality of the world is now shown to be meaningless, because “reality” cannot be tested in another way than by our experience, our sensations. So the chain of progressive constitutings is broken off here.
It is easy to see the limitedness of this world structure. It is not finished. The world thus constituted by Mach and by Carnap is a momentary world supposed unchanging. The fact that the world is in continuous evolution is disregarded. So we must go on past where Carnap stopped. According to our experience people are born and die; their sensations arise and disappear, but the world remains. When my sensations out of which the world was constituted, cease with my death, the world continues to exist. From acknowledged scientific facts I know that long ago there was a world without man, without any living being. The facts of evolution, founded on our sensations condensed into science, establish a previous world without any sensations. Thus from an intersubjective world common to all mankind, constituted as a world of phenomena by science, we proceed to the constitution of an objective world. Then the entire world view changes. Once the objective world is constituted, all phenomena become independent of observing man, as relations between parts of the world, The world is the totality of an infinite number of parts acting upon another; every part consists in the totality of its actions and reactions with the rest, and all these mutual actions are the phenomena, the object of science.
Man also is part of the world; we too are the totality of our mutual interactions with the rest, the outer world. Our sensations are now seen in a new light; they are the actions of the world upon us, only a small part of all happenings in the world but, of course, the only ones immediately given to us. When now man is building up the world out of his sensations, it is a reconstruction in the mind of an already objectively existing world. Again we have the world twofold, with all the problems of epistemology, the theory of knowledge. How they may be solved without metaphysics is shown by Historical Materialism.
If one asks why two such prominent philosophers of science omitted this obvious step toward the constitution of an objective world, the answer can only be found in their middle-class world view. Their instinctive tenet is anti-materialistic. By adhering to the intersubjective world they have won a monistic world system, the physical world consisting of psychical elements, so that materialism is refuted. We have here an instructive example how class views determine science and philosophy.
Summarising Mach’s ideas we distinguish two steps. First the phenomena are reduced to sensations expressing their subjective character. Through the desire to find direct reality only in the sensations as psychical entities, he does not proceed by precise deductions to an objective world that obviously is matter of fact, though in a mystical vague way. Then comes a second step from the world of phenomena to the physical world. What physics, and by the popular dispersion of science also common opinion, assumes as the reality of the world – matter, atoms, energy, natural laws, the forms of space and time. myself – are all abstractions from groups of phenomena. Mach combines both steps into one by saying that things are sensation-complexes.
The second step corresponds to Dietzgen; the similarity here is manifest. The differences are accounted for by their different class views. Dietzgen stood on the basis of dialectic materialism, and his expositions were a direct consequence of Marxism. Mach, borne by the incipient reaction of the bourgeoisie, saw his task in a fundamental criticism of physical materialism by asserting dominance to some spiritual principle. There is a difference, moreover, in personality and aims. Dietzgen was a comprehensive philosopher, eager to find out how our brains work; the practice of life and science was to him material for the knowledge of knowledge. Mach was a physicist who by his criticisms tries to improve the ways in which brains worked in scientific investigations. Dietzgen’s aim was to give clear insight into the role of knowledge in social development, for the use of the proletarian struggle. Mach’s aim was an amelioration of the practice of physical research, for the use of natural science.
Speaking of practice, Mach expresses himself in different ways. At one time he sees no utility in employing the ordinary abstractions: “We know only of sensations, and the assumption of those nuclei (particles of matter) and their mutual actions as the assigned origins of sensations, shows itself entirely futile and superfluous” (Analyse der Empfindungen, p.10). Another time he does not wish to discredit the common view of unsophisticated “naive realism,” because it renders great services to mankind in their common life. It has grown as a product of nature, whereas every philosophical system is an ephemeral product of art, for temporary aims. So we have to see “why and to what purposes we usually take one point of view, and why and to what purpose we temporarily give it up. No point of view holds absolutely; each imports for special aims only” (Analyse der Empfindungen, p.30).
In the practical application of his views upon physics Mach met with little success. His campaign was chiefly directed against matter and atoms dominating physical science. Not simply because they are and should be acknowledged as abstractions: “Atoms we can observe nowhere, they are as every substance products of thought” (Die Mechanik in ihrer Entwicklung, p.463). But because they are impractical abstractions. They mean an attempt to reduce all physics to mechanics, to the motion of small particles, “and it is easy to see that by mechanical hypotheses a real economy of scientific thought cannot be achieved” (Die Mechanik in ihrer Entwicklung, p.469). But his criticism of heat as a form of motion of small particles, already in 1873, and of electricity as a streaming fluid, found no echo among physicists. On the contrary these explanations developed in ever wider applications, and their consequences were confirmed ever again; atomic theory could boast of ever more results and was extended even to electricity in the theory of electrons. Hence the generation of physicists that followed him, while sympathising with his general views and accepting them, did not follow him in ms special applications. Only in the new century, when atomic and electronic theory had progressed in a brilliant display, and when the theory of relativity arose, there appeared a host of glaring contradictions in which Mach’s principles showed themselves the best guides in clearing up the difficulties.
1. The phrase “middle class” is here used as a translation for the German word “bürgerlich”. The more modern term used in Marxist discourse for this concept is “bourgeois” (i.e. relating to the capitalist or bourgeois class) in order to distinguish it from the rather imprecise term “middle class”, which is often used as a broad description for white-collar workers, professionals, the self-employed etc. Similarly when this text refers to “the middle class” it is referring to the bourgeoisie or capitalist class. (Note by MIA)
Last updated on 2.7.2004