" It must be the duty of racial hygiene to be attentive to a more severe elimination of morally inferior human beings than is the case today .... We should literally replace all factors responsible for selection in a natural and free life .... In prehistoric times of humanity, selection for endurance, heroism, social usefulness, etc. was made solely by hostile outside factors. This role must be assumed by a human organization; otherwise, humanity will, for lack of selective factors, be annihilated by the degenerative phenomena that accompany domestication. "