The perception of the fundamental contradiction in German idealism led necessarily back to materialism, but _nota bene_, not to the simply metaphysical, exclusively mechanical materialism of the eighteenth century. Old materialism looked upon all previous history as a crude heap of irrationality and violence; modern materialism sees in it the process of evolution of humanity, and aims at discovering the laws thereof. With the French of the eighteenth century, and even with Hegel, the conception obtained of Nature as a whole, moving in narrow circles, and forever immutable, with its eternal celestial bodies, as Newton, and unalterable organic species, as Linnæus, taught. Modern materialism embraces the more recent discoveries of natural science, according to which Nature also has its history in time, the celestial bodies, like the organic species that, under favorable conditions, people them, being born and perishing. And even if Nature, as a whole, must still be said to move in recurrent cycles, these cycles assume infinitely larger dimensions. In both aspects, modern materialism is essentially dialectic, and no longer requires the assistance of that sort of philosophy which, queen-like, pretended to rule the remaining mob of sciences. As soon as each special science is bound to make clear its position in the great totality of things and of our knowledge of things, a special science dealing with this totality is superfluous or unnecessary. That which still survives of all earlier philosophy is the science of thought and its laws--formal logic and dialectics. Everything else is subsumed in the positive science of Nature and history.