Every man has manifold wants for the satisfaction of which he depends on others. His wants are legion; his ability and opportunity to satisfy them exceedingly limited. It is this cross relation that expresses the so-called social nature of man. But the reciprocal dependence of men upon one another for the satisfaction of their wants by no means constitutes an ethical tie. The tie between the Greek master and the Greek slave, as described by Aristotle, was social, but not ethical. The same is true of the tie that united the Southern planter to his negro slaves. The relation was indeed far more social than that between the modern mill-owner and the operatives in his factory, but still it was not ethical. The reason is clearly stated by Aristotle himself. According to him the slave is a living tool: the purpose of his existence is not realized in himself but in his master. He fulfils the end of his being by setting free the higher functions exercised by his master. But from the ethical point of view no man may be regarded as the tool of another. Each human being is an end _per se_, and the highest object of his existence is to be fulfilled, not in others, but jointly in them and in himself. I have just said that the social and the ethical views are not synonymous or coincident, as the loose use of language in current literature would imply. I go farther and say that the social and the ethical point of view are even on their face contradictory. It cannot be denied that the natural system of interdependence resembles that of the body and its members. A hierarchy of organs and of functions is apparent in the human body, and likewise in the social body. Some men do the lowest kind of work. Their function appears to be to produce food, clothing and shelter, to satisfy the mere physical wants. Some are the hands, so to speak, of society, while only a very few effectually represent the brain. The simile has been carried out in detail by well-known writers, in both ancient and modern times. It is quite true that the artist and the scientist are dependent on the manual laborer, just as he in turn is dependent on them. But then, consider the difference in the dignity of the services they render one another. Was not the Greek, who saw things dispassionately as they are, right in asserting that, taking society in the large, the purpose of human life is fulfilled in the few, and that the greater number exist in order that by their inferior services they may enable these few to express humanity in its highest terms? It seems to me that the kind of social arrangement contemplated by the great Greek philosophers, and by some of the mediæval publicists, as well as by certain modern thinkers, is unquestionably social. The fact of interdependence is stressed by them. The ethical note of equality, or, as I should prefer to put it, equivalence, is left out.