With true prophetic insight Proudhon perceived the fact that even in human society revolution is everything; with a clearness of vision such as none before him, and only very few after him, have possessed, he always insisted upon the organic character of human society and the natural continuity between animal and human social life; and in this lies his greatness, which will never be diminished by any of his numerous errors. But while he thus with one foot for the first time trod upon the ground of a new discovery, with the other he stood on the standpoint of social philosophy of previous centuries. He could neither externally nor internally disassociate himself from its baseless assumptions of a social contract, the absolute rights of man, a moral order of the universe, and similar ethical views of politics; and herein lies the contradiction upon which his great mental talents were shipwrecked. If we once regard human society as Proudhon did, as something real, the product of nature which is moved and develops itself according to the laws of the rest of nature, then we have once for all given up the right to mark out for it a line of development determined merely by speculation, or to demand from it that it should move towards any particular goal, however well-intentioned it may be. A breeder may produce in his pigeons or fowls a certain kind of feather or a certain form of pouting, but he cannot change the pigeon into a hen. The artificial selection of breeding is all that man can do (_pour corriger la nature_) against the free progress of natural development. This is not so insignificant as one may be inclined to believe at the first glance. The latter belongs to the category of Ovid's _Metamorphoses_, and of that Utopian social philosophy which began with Plato, and in all human probability will not end for a long time. Proudhon wished to unite both, one with another,--to unite water with fire. Like all Utopians, he desired--he who all his life, in his numerous writings, so frequently confuted and sneered at them--that the human race might be metamorphosed in order to accept unanimously his ideas about society. For that the men of his day were not fit for a true democracy--that is, for anarchy--he was honest enough to admit.