Anti-Dühring by Frederick Engels 1877
Part I: Philosophy

VI. Philosophy of Nature.
Cosmogony, Physics, Chemistry

Passing on, we come now to the theories concerning the manner in which the present world came into existence.

A state of universal dispersion of matter, we are told, was the point of departure of the ionic philosophers, but later, particularly from the time of Kant, the assumption of a primordial nebula played a new role, gravitation and the radiation of heat having been instrumental in the gradual formation of separate solid celestial bodies. The contemporary mechanical theory of heat makes it possible to deduce the earlier states of the universe in a far more definite form. However, “the state of gaseous dispersion can be a starting-point for serious deductions only when it is possible to characterise beforehand more definitely the mechanical system existing in it. Otherwise not only does the idea in fact remain extremely nebulous, but also the original nebula, as the deductions progress, really becomes ever thicker and more impenetrable; ... meanwhile it all still remains in the vagueness and formlessness of an idea of diffusion that cannot be more closely determined”, and so “this gaseous universe” provides us with “only an extremely airy conception” {D. Ph. 85-87}.

The Kantian theory of the origin of all existing celestial bodies from rotating nebular masses was the greatest advance made by astronomy since Copernicus. For the first time the conception that nature had no history in time began to be shaken. Until then the celestial bodies were believed to have been always, from the very beginning, in the same states and always to have followed the same courses; and even though individual organisms on the various celestial bodies died out, nevertheless genera and species were held to be immutable. It is true that nature was obviously in constant motion, but this motion appeared as an incessant repetition of the same processes. Kant made the first breach in this conception, which corresponded exactly to the metaphysical mode of thought, and he did it in such a scientific way that most of the proofs furnished by him still hold good today. At the same time, the Kantian theory is still, strictly considered, only a hypothesis. But the Copernican world system, too, is still no more than this, [38] and since the spectroscopic proof of the existence of such red-hot gaseous masses in the starry heavens, proof that brooks no contradiction, the scientific opposition to Kant ’s theory has been silenced. Even Herr Dühring cannot complete his construction of the world without such a nebular stage, but takes his revenge for this by demanding to be shown the mechanical system existing in this nebular stage, and because no one can show him this, he applies all kinds of depreciatory epithets to this nebular stage of the universe. Contemporary science unfortunately cannot describe this system to Herr Dühring ’s satisfaction. Just as little is it able to answer many other questions. To the question: Why do toads have no tails? — up to now it has only been able to answer: Because they have lost them. But should anyone get excited over that and say that this is to leave the whole question in the vagueness and formlessness of an idea of loss which cannot be determined more closely, and that it is an extremely airy conception, such an application of morality to natural science does not take us one step further. Such expressions of dislike and bad temper can be used always and everywhere, and just for that reason they should never be used anywhere. After all, who is stopping Herr Dühring from himself discovering the mechanical system of the primordial nebula?

Fortunately we now learn that

the Kantian nebular mass “is far from coinciding with a completely identical state of the world medium, or, to put it another way, with the self-equal state of matter” {D. Ph. 87}.

It was really fortunate for Kant that he was able to content himself with going back from the existing celestial bodies to the nebular ball, and did not even dream of the self-equal state of matter! It may be remarked in passing that when contemporary natural science describes the Kantian nebular ball as primordial nebula, this, it goes without saying, is only to be understood in a relative sense. It is primordial nebula, on the one hand, in that it is the origin of the existing celestial bodies, and on the other hand because it is the earliest form of matter which we have up to now been able to work back to. This certainly does not exclude but rather implies the supposition that before the nebular stage matter passed through an infinite series of other forms.

Herr Dühring sees his advantage here. Where we, with science, stand still for the time being at what for the time being is deemed primordial nebula, his science of sciences helps him much further back to that

“state of the world medium which cannot be understood either as purely static in the present meaning of the idea, or as dynamic” {87} —

which therefore cannot be understood at all.

“The unity of matter and mechanical force which we call the world medium is what might be termed a logical-real formula for indicating the self-equal state of matter as the prerequisite of all innumerable stages of evolution” {87-88}.

We are clearly not by a long shot rid of the self-equal primordial state of matter. Here it is spoken of as the unity of matter and mechanical force, and this as a logical-real formula, etc. Hence, as soon as the unity of matter and mechanical force comes to an end, motion begins.

The logical-real formula is nothing but a lame attempt to make the Hegelian categories “in itself ” [An sich] and "for itself" [Für sich] usable in the philosophy of reality. With Hegel, “in itself ” covers the original identity of the hidden, undeveloped contradictions within a thing, a process or an idea, and “for itself ” contains the distinction and separation of these hidden elements and the starting-point of their conflict. We are therefore to think of the motionless primordial state as the unity of matter and mechanical force, and of the transition to movement as their separation and opposition. What we have gained by this is not any proof of the reality of that fantastic primordial state, but only the fact that it is possible to bring this state under the Hegelian category of “in itself”, and its equally fantastic termination under the category of “for itself”. Hegel help us!

Matter, Herr Dühring says, is the bearer of all reality; accordingly, there can be no mechanical force apart from matter. Mechanical force is furthermore a state of matter {See D. Ph. 73}. In the original state, when nothing happened, matter and its state, mechanical force, were one. Afterwards, when something began to happen, this state must apparently have become different from matter. So we are to let ourselves be dismissed with these mystical phrases and with the assurance that the self-equal state was neither static nor dynamic, neither in equilibrium nor in motion. We still do not know where mechanical force was in that state, and how we are to get from absolute immobility to motion without an impulse from outside, that is, without God.

The materialists before Herr Dühring spoke of matter and motion. He reduces motion to mechanical force as its supposed basic form, and thereby makes it impossible for himself to understand the real connection between matter and motion, which moreover was also unclear to all former materialists. And yet it is simple enough. Motion is the mode of existence of matter. Never anywhere has there been matter without motion, nor can there be. Motion in cosmic space, mechanical motion of smaller masses on the various celestial bodies, the vibration of molecules as heat or as electrical or magnetic currents, chemical disintegration and combination, organic life — at each given moment each individual atom of matter in the world is in one or other of these forms of motion, or in several forms at once. All rest, all equilibrium, is only relative, only has meaning in relation to one or other definite form of motion. On the earth, for example, a body may be in mechanical equilibrium, may be mechanically at rest; but this in no way prevents it from participating in the motion of the earth and in that of the whole solar system, just as little as it prevents its most minute physical particles from carrying out the vibrations determined by its temperature, or its atoms from passing through a chemical process. Matter without motion is just as inconceivable as motion without matter. Motion is therefore as uncreatable and indestructible as matter itself; as the older philosophy (Descartes) expressed it, the quantity of motion existing in the world is always the same. Motion therefore cannot be created; it can only be transferred. When motion is transferred from one body to another, it may be regarded, in so far as it transfers itself, is active, as the- cause of motion, in so far as the latter is transferred, is passive. We call this active motion force, and the passive, the manifestation of force. Hence it is as clear as daylight that a force is as great as its manifestation, because in fact the same motion takes place in both.

A motionless state of matter is therefore one of the most empty and nonsensical of ideas — a “delirious fantasy ” of the purest water. In order to arrive at such an idea it is necessary to conceive the relative mechanical equilibrium, a state in which a body on the earth may be, as absolute rest, and then to extend this equilibrium over the whole universe. This is certainly made easier if universal motion is reduced to purely mechanical force. And the restriction of motion to purely mechanical force has the further advantage that a force can be conceived as at rest, as tied up, and therefore for the moment inoperative. For if, as is very often the case, the transfer of a motion is a somewhat complex process containing a number of intermediate links, it is possible to postpone the actual transmission to any moment desired by omitting the last link in the chain. This is the case, for instance, if a man loads a gun and postpones the moment when, by the pulling of the trigger, the discharge, the transfer of the motion set free by the combustion of the powder, takes place. It is therefore possible to imagine that during its motionless, self-equal state, matter was loaded with force, and this, if anything at all, seems to be what Herr Dühring understands by the unity of matter and mechanical force. This conception is nonsensical, because it transfers to the entire universe a state as absolute, which by its nature is relative and therefore can only affect a part of matter at any one time. Even if we overlook this point, the difficulty still remains: first, how did the world come to be loaded, since nowadays guns do not load themselves; and second, whose finger was it then that pulled the trigger? We may turn and twist as much as we like, but under Herr Dühring's guidance we always come back again to — the finger of God.

From astronomy our philosopher of reality passes on to mechanics and physics, and voices the lament that the mechanical theory of heat has not, in the generation since its discovery, been materially advanced beyond the point to which Robert Mayer had himself developed it, bit by bit. Apart from this, the whole business is still very obscure;

we must “always remember that in the states of motion of matter, static relations are also present, and that these latter are not measurable by the mechanical work ... if previously we described nature as a great worker, and if we now construe this expression strictly, we must furthermore add that the self-equal states and static relations do not represent mechanical work. So once again we miss the bridge from the static to the dynamic, and if so-called latent heat has up to now remained a stumbling-block for the theory, we must recognise a defect in this too, which can least be denied in its cosmic applications” {D. Ph. 90}.

This whole oracular discourse is once again nothing but the outpouring of a bad conscience, which is very well aware that with its creation of motion out of absolute immobility it got irretrievably stuck in the mud, but is nevertheless ashamed to appeal to the only possible saviour, namely, the creator of heaven and earth. If the bridge from the static to the dynamic, from equilibrium to motion, cannot be found even in mechanics, including the mechanics of heat, under what obligations is Herr Dühring to find the bridge from his motionless state to motion? That would be a fortunate way for him to get out of his plight.

In ordinary mechanics the bridge from the static to the dynamic is — the external impulse. If a stone weighing a hundredweight is raised from the ground ten yards into the air and is freely suspended in such a way that it remains hanging there in a self-equal state and in a condition of rest, it would be necessary to have an audience of sucklings to be able to maintain that the present position of this body does not represent any mechanical work, or that its distance from its previous position is not measurable by mechanical work. Any passer-by will easily explain to Herr Dühring that the stone did not rise of itself to the rope and any manual of mechanics will tell him that if he lets the stone fall again it performs in falling just as much mechanical work as was necessary to raise it the ten yards in the air. Even the simple fact that the stone is hanging up there represents mechanical work, for if it remains hanging long enough the rope breaks, as soon as chemical decomposition makes it no longer strong enough to bear the weight of the stone. But it is to such simple basic forms, to use Herr Dühring's language, that all mechanical processes can be reduced, and the engineer is still to be born who cannot find the bridge from the static to the dynamic, so long as he has at his disposal a sufficient external impulse.

To be sure, it is a hard nut and a bitter pill for our metaphysician that motion should find its measure in its opposite, in rest. That is indeed a crying contradiction, and every contradiction, according to Herr Dühring, is nonsense {D. Ph. 30}. It is none the less a fact that a suspended stone represents a definite quantity of mechanical motion, which is measurable exactly by the stone's weight and its distance from the ground, and may be used in various ways at will, for example, by its direct fall, by sliding down an inclined plane, or by turning a shaft. The same is true of a loaded gun. From the dialectical standpoint, the possibility of expressing motion in its opposite, in rest, presents absolutely no difficulty. From the dialectical standpoint the whole antithesis, as we have seen, is only relative; there is no such thing as absolute rest, unconditional equilibrium. Each separate movement strives towards equilibrium, and the motion as a whole puts an end again to the equilibrium. When therefore rest and equilibrium occur they are the result of limited motion, and it is self-evident that this motion is measurable by its result, can be expressed in it, and can be restored out of it again in one form or another. But Herr Dühring cannot allow himself to be satisfied with such a simple presentation of the matter. As a good metaphysician he first tears open, between motion and equilibrium, a yawning gulf which does not exist in reality and is then surprised that he cannot find any bridge across this self-fabricated gulf. He might just as well mount his metaphysical Rosinante [Don Quixote’s horse] and chase the Kantian “thing-in-itself”; for it is that and nothing else which in the last analysis is hiding behind this undiscoverable bridge.

But what about the mechanical theory of heat and the tied-up or latent heat which “has remained a stumbling-block” for this theory?

If, under normal atmospheric pressure, a pound of ice at the temperature of the freezing point is transformed by heat into a pound of water of the same temperature, a quantity of heat disappears which would be sufficient to warm the same pound of water from 0° to 79.4° C, or to raise the temperature of 79.4 pounds of water by one degree. If this pound of water is heated to boiling point, that is, to 100° C, and is then transformed into steam of 100° C, the amount of heat that disappears, by the time the last of the water has changed into steam, is almost seven times greater, sufficient to raise the temperature of 537.2 pounds of water by one degree. The heat that disappears is called tied-up. If, by cooling, the steam is again transformed into water, and the water, in its turn, into ice, the same quantity of heat as was previously tied up is now again set free, i.e., can be felt and measured as heat. This setting free of heat on the condensation of steam and the freezing of water is the reason why steam, when cooled to 100°, is only gradually transformed into water, and why a mass of water of freezing point temperature is only very gradually transformed into ice. These are the facts. The question is, what happens to the heat while it is tied up?

The mechanical theory of heat, according to which heat consists in a greater or lesser vibration, depending on the temperature and state of aggregation, of the smallest physically active particles (molecules) of a body — a vibration which under certain conditions can change into any other form of motion — explains that the heat that has disappeared has done work, has been transformed into work. When ice melts, the close and firm connection between the individual molecules is broken, and transformed into a loose juxtaposition; when water at boiling point becomes steam a state is reached in which the individual molecules no longer have any noticeable influence on one another, and under the influence of heat even fly apart in all directions. It is clear that the single molecules of a body are endowed with far greater energy in the gaseous state than they are in the fluid state, and in the fluid state again more than in the solid state. The tied-up heat, therefore, has not disappeared; it has merely been transformed, and has assumed the form of molecular tension. As soon as the condition under which the separate molecules are able to maintain their absolute or relative freedom in regard to one another ceases to exist — that is, as soon as the temperature falls below the minimum of 100° or 0°, as the case may be, this tension relaxes, the molecules again press towards each other with the same force with which they had previously flown apart; and this force disappears, but only to reappear as heat, and as precisely the same quantity of heat as had previously been tied up. This explanation is of course a hypothesis, as is the whole mechanical theory of heat, inasmuch as no one has up to now ever seen a molecule, not to mention one in vibration. Just for this reason it is certain to be full of defects as this still very young theory is as a whole, but it can at least explain what happens without in any way coming into conflict with the indestructibility and uncreatability of motion, and it is even able to account for the whereabouts of heat during its transformations. Latent, or tied-up, heat is therefore in no way a stumbling-block for the mechanical theory of heat. On the contrary, this theory provides the first rational explanation of what takes place, and it involves no stumbling-block except in so far as physicists continue to describe heat which has been transformed into another form of molecular energy by means of the term “tied-up”, which has become obsolete and unsuitable.

The self-equal states and conditions of rest in the solid, in the liquid and in the gaseous state of aggregation therefore represent, to be sure, mechanical work, in so far as mechanical work is the measure of heat. Both the solid crust of the earth and the water of the ocean, in their present aggregate states, represent a definite quantity of heat set free, to which of course corresponds an equally definite quantity of mechanical force. In the transition of the gaseous ball, from which the earth has developed, into the liquid and subsequently into the largely solid aggregate state, a definite quantity of molecular energy was radiated as heat into space. The difficulty about which Herr Dühring mumbles in his mysterious manner therefore does not exist, and though even in applying the theory cosmically we may come up against defects and gaps — which must be attributed to our imperfect means of knowledge — we nowhere come up against theoretically insuperable obstacles. The bridge from the static to the dynamic is here, too, the external impulse — the cooling or heating brought about by other bodies acting on an object which is in a state of equilibrium. The further we explore this natural philosophy of Dühring's, the more impossible appear all attempts to explain motion out of immobility or to find the bridge over which the purely static, the resting, can by itself pass to the dynamic, to motion.

With this we have fortunately rid ourselves for a time of the self-equal primordial state. Herr Dühring passes on to chemistry, and takes the opportunity to reveal to us three laws of nature's inertness which have so far been discovered by his philosophy of reality, viz.:

(1) the quantity of all matter in general, (2) that of the simple (chemical) elements, and (3) that of mechanical force are constant {D. Ph. 97}

Hence: the uncreatability and indestructibility of matter, and also of its simple component parts, in so far as it is made up of such, as well as the uncreatability and indestructibility of motion — these old facts known the world over and expressed most inadequately — is the only positive thing which Herr Dühring can provide us with as a result of his natural philosophy of the inorganic world. We knew all this long ago. But what we did not know was that they were “laws of inertness” and as such “schematic properties of the system of things”. We are witnessing a repetition of what happened above to Kant: Herr Dühring picks up some old familiar quip, sticks a Dühring label on it, and calls the result:

“from the ground up original conclusions and views ... system-creating ideas {525} deep-rooted science” {200, 219; D. C. 555-56}.

But the need not by any means despair on this account. Whatever defects even the most deep-rooted science and the best-ordered society may have, Herr Dühring can at any rate assert one thing with confidence:

“The amount of gold existing in the universe must at all times have been the same, and it can have increased or diminished just as little as can matter in general” {D. Ph. 96}.

Unfortunately Herr Dühring does not tell us what we can buy with this “existing gold”.