by the political and social needs of the bourgeoisie. It was just the representatives of the catastrophe theories who were at the same time most reactionary and least inclined to revolutionary views. But every one is involuntarily influenced by the mental attitude of the class amid which he lives and carries something from it into his scientific conceptions. In the case of Darwin we know positively that his natural science hypotheses were influenced by Malthus, that decisive opponent of revolution. It was not wholly accidental that the theories of evolution (of Darwin and Lyell) came from England, whose history for 250 years has shown nothing more than revolutionary beginnings, whose point the ruling class have always been able to break at the opportune moment.
The fact that an idea emanates from any particular class, or accords with their interests, of course proves nothing as to its truth or falsity. But its historical influence does depend upon just these things. That the new theories of evolution were quickly accepted by the great popular masses, who had absolutely no possibility of testing them, proves that they rested upon profound needs of those classes. On the one side these theories—and this gave them their value to the revolutionary classes—abolished in a much more radical manner than the old catastrophic theories, all necessity of a recognition of a supernatural power creat-
