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.
Julian Huxley