In spite of all this "the universal condition of the gaseous form can only be a point of departure for serious conclusions if one can define the mechanical system of it more precisely beforehand. If not, the idea becomes not only very cloudy, but the original nebula becomes really in the progress of those conclusions denser and more impenetrable."... For the present everything remains in the vagueness and formlessness of an indefinite idea, and so with regard to the gaseous universe we have only an insubstantial conception. The theory of Kant that all existing worlds were created from a mass of rotating vapor was the greatest advance made by astronomy since the days of Copernicus. The idea that nature had no history in time was then shaken for the first time. Up to then the worlds were fixed in bounds and conditions from their very beginning, and though the individual organisms on the separate worlds were transient, the species remained unalterable. Nature was conceived as an apparently limited movement and its motion seemed to be the repetition of the same movements perpetually. It was in this conception which is entire accord with the metaphysical mode of thought that Kant made the first breach and so scientifically that most of his grounds of proof stand good to-day. Really the theory of Kant is a mere hypothesis even to-day. The Copernican theory of the universe has no longer any weight and since the spectroscope discovered such glowing gaseous matter in space all objections have been disposed of and scientific opposition to Kant's theory has been silenced. Even Herr Duehring cannot produce his universe without the nebulous state and he takes his revenge by asking to be shown the mechanical system of this nebulous state and because this cannot be done he inflicts all sorts of contemptuous remarks upon this nebulous state. Unfortunately modern science cannot show this system and please Herr Duehring. But there are many other questions which it cannot answer. For example regarding the question why toads have no tails it can only answer so far "Because they have lost them." But if people get angry and say that this is all vague and formless, a mere fanciful idea, incapable of being made definite and a very poor notion, such views would not carry us a step further, scientifically. Such insults and exaggerations are sufficiently numerous. What is there to hinder Herr Duehring himself from discovering the mechanical system of the original nebular state?