But the greater human intelligence in itself does not cause the differences that exist This psychic superiority is only the indispensable condition of what is peculiarly human: civilization. Directly, it is the civilization in which every Eskimo, every Alaskan miner or arctic discoverer is reared, and not any greater inborn faculty, that leads him to build houses, ignite fire, and wear clothing. The distinction between animal and man which counts is not that of the physical and mental, which is one of relative degree, but of the organic and the social, which is one of kind. The beast has mentality, and we have bodies; but in civilization man has something that no animal has.