Blood mixture and the result drop in the racial level is the sole cause of the dying out of old cultures; for men do not perish as a result of lost wars, but by the loss of that force of resistance which is continued only in pure blood. All who are not of good race in this world are chaff.

Segregationalists will even argue that God was the first segregationalist. 'Red birds and blue birds don't fly together,' they contend. ...They turn to some pseudo-scientific writing and argue that the Negro's brain is smaller than the white man's brain. They do not know, or they refuse to know that the idea of an inferior or superior race has been refuted by the best evidence of the science of anthropology. Great anthropologists, like Ruth Benedict, Margaret Mead, and Melville J. Herskovits, agree that, although there may be inferior and superior individuals within all races, there is no superior or inferior race. And segregationalists refuse to acknowledge that there are four types of blood, and these four types are found within every racial group.

The fundamental problem in the origin of species is not the origin of differences in appearance, since these arise at the level of the geographical race, but the origin of genetic segregation. The test of species-formation is whether, when two forms meet, they interbreed and merge, or whether they keep distinct.

The philosophical implication of race-thinking is that by offering us the mystery of heredity as an explanation, it diverts our attention from the social and intellectual factors that make up personality.

The popular and scientific views of 'race' no longer coincide. The word 'race', as applied scientifically to human groupings, has lost any sharpness of meaning. To-day it is hardly definable in scientific terms, except as an abstract concept which may, under certain conditions, very different from those now prevalent, have been realized approximately in the past and might, under certain other but equally different conditions, be realized in the distant future.
Co-author with British anthropologist Alfred Cort Haddon (1855-1940).

While we maintain the unity of the human species, we at the same time repel the depressing assumption of superior and inferior races of men. There are nations more susceptible of cultivation, more highly civilized, more ennobled by mental cultivation than others—but none in themselves nobler than others. All are in like degree designed for freedom.