At a congress of naturalists, the reactionary politician and scientist Virchow assailed the Darwinian theory on the ground that it supported Socialism. “Be careful of this theory,” he said to the Darwinists, “for this theory is very nearly related to the theory that caused so much dread in our neighboring country.” This allusion to the Paris Commune, made in the year famous for the hunting of Socialists, must have had a great effect. What shall be said, however, about the science of a professor who attacks Darwinism with the argument that it is not correct because it is dangerous! This reproach, of being in league with the red revolutionists, caused a lot of annoyance to Haeckel, the defendant of this theory. He could not stand it. Immediately afterwards he tried to demonstrate that it is just the Darwinian theory that shows the untenableness of the Socialist demands, and that Darwinism and Socialism “endure each other as fire and water.” Let us follow Haeckel’s contentions, whose main thoughts re-occur in most authors who base their arguments against Socialism on Darwinism. Socialism is a theory which presupposes natural equality for people, and strives to bring about social equality; equal rights, equal duties, equal possessions and equal enjoyments. Darwinism, on the contrary, is the scientific proof of inequality. The theory of descent establishes the fact that animal development goes in the direction of ever greater differentiation or division of labor; the higher or more perfect the animal, the greater the inequality existing. The same holds also good in society. Here, too, we see the great division of labor between vocations, class, etc., and the higher we stand in social development the greater become the inequalities in strength, ability and faculty. The theory of descent is therefore to be recommended as “the best antidote to the Socialist demand of making all equal.” The same holds good, but to a greater extent, of the Darwinian theory of survival. Socialism wants to abolish competition and the struggle for existence. But Darwinism teaches us that this struggle is unavoidable and is a natural law for the entire organic world. Not only is this struggle natural, but it is also useful and beneficial. This struggle brings an ever greater perfection, and this perfection consists in an ever greater extermination of the unfit. Only the chosen minority, those who are qualified to withstand competition, can survive; the great majority must perish. Many are called, but few are chosen. The struggle for existence results at the same time in a victory for the best, while the bad and unfit must perish. This may be lamentable, just as it is lamentable that all must die, but the fact can neither be denied nor changed.