Those people that perish as people are members of an entirely different class, a class that does not take part in the competitive struggle. The workers do not compete with the capitalists, they only sell their labor power to them. Owing to their being propertyless, they have not even the opportunity to measure their great qualities and enter a race with the capitalists. Their poverty and misery cannot be attributed to the fact that they fell in the competitive struggle on account of weakness, but because they were paid very little for their labor power, it is for this very reason that, although their children are born strong and healthy, they perish in great mass, while the children born to rich parents, although born sick, remain alive by means of the nourishment and great care that is bestowed on them. These children of the poor do not die because they are sick or weak, but because of external cause. It is capitalism which creates all those unfavorable conditions by means of exploitation, reduction of wages, unemployment, crises, bad dwellings, and long hours of employment. It is the capitalist system that causes so many strong and healthy ones to succumb. Thus the Socialists prove that, different from the animal world, the competitive struggle existing between men does not bring forth the best and most qualified, but destroys many strong and healthy ones because of their poverty, while those that are rich, even if weak and sick, survive. Socialists prove that personal strength is not the determining factor, but it is something outside of man; it is the possession of money that determines who shall survive and who shall perish. VI. NATURAL LAW AND SOCIAL THEORY. The false conclusions reached by Haeckel and Spencer on Socialism are no surprise. Darwinism and Marxism are two distinct theories, one of which applies to the animal world, while the other applies to society. They supplement each other in the sense that, according to the Darwinian theory of evolution, the animal world develops up to the stage of man, and from then on, that is, after the animal has risen to man, the Marxian theory of evolution applies. When, however, one wishes to carry the theory of one domain into that of the other, where different laws are applicable, he must draw wrong inferences.