The proof given by Wright, that non-adaptive differentiation will occur in small populations owing to "drift," or the chance fixation of some new mutation or recombination, is one of the most important results of mathematical analysis applied to the facts of neo-mendelism. It gives accident as well as adaptation a place in evolution, and at one stroke explains many facts which puzzled earlier selectionists, notably the much greater degree of divergence shown by island than mainland forms, by forms in isolated lakes than in continuous river-systems.

The lowest strata are reproducing too fast. Therefore... they must not have too easy access to relief or hospital treatment lest the removal of the last check on natural selection should make it too easy for children to be produced or to survive; long unemployment should be a ground for sterilisation.

Sooner or later, false thinking brings wrong conduct.

The scientific doctrine of progress is destined to replace not only the myth of progress, but all other myths of human earthly destiny. It will inevitably become one of the cornerstones of man's theology, or whatever may be the future substitute for theology, and the most important external support for human ethics.

...it is curiosity, initiative, originality, and the ruthless application of honesty that count in research- much more than feats of logic and memory alone.

Evolution is nothing but matter become conscious of itself.

...any belief in supernatural creators, rulers, or influencers of natural or human process introduces an irreparable split into the universe, and prevents us from grasping its real unity. Any belief in Absolutes, whether the absolute validity of moral commandments, of authority of revelation, of inner certitudes, or of divine inspiration, erects a formidable barrier against progress and the responsibility of improvement, moral, rational, and religious.