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" [ Ansich ] and "for itself" [ Fursich ]
