Sigmund Freud put the issue of human supremacy in perspective in 1917 when he wrote: "In the course of his development towards culture man acquired a dominating position over his fellow-creatures in the animal kingdom. Not content with this supremacy, however, he began to place a gulf between his nature and theirs. He denied the possession of reason to them, and to himself he attributed an immortal soul, and made claims to a divine descent which permitted him to annihilate the bond of community between him and the animal kingdom.