In the second place, this uniformity is supremely undesirable from the purely evolutionary point of view, because its attainment would mean the arrest of all progress. All organic evolution, as we know, depends upon the struggle between creatures possessing variations and the consequent selection of those variations which constitute their possessors best adapted or fitted to the particular environment. If there is no variation there can be no evolution. To aim at the suppression of variation, therefore, on supposed eugenic grounds (which would be involved in aiming at any uniform type of mankind) would be to aim at destroying the necessary condition of all racial progress. The mere fact that the critics of race-culture attribute to evolutionists, of all people, the desire to suppress variation, is a pathognomic symptom of their critical quality. And, of course, quite independently of the evolutionary function of variation--though this is cardinal and must never be forgotten by the politician of any school, since what we call individuality is variation on the human plane--the value of variation in ordinary life is wholly incalculable. It is not merely that, as Mr. Galton says, “There are a vast number of conflicting ideals, of alternative characters, of incompatible civilisations; but they are wanted to give fulness and interest to life. Society would be very dull if every man resembled the highly estimable Marcus Aurelius or Adam Bede.” The question is not merely as to the interest of life. Much more important is the fact that it takes all sorts to make a world. What is the development of society but the result of the psychological division of labour in the social organism? And how could such division of labour be carried out if we had not various types of labourers? What would be the good of science if there were no poetry or music to live for? How would poetry and music help us if we had not men of science to protect our shores from plague?