dividual’s chance of survival is impaired. Development in some individuals, by special environment and training, of mental capacity beyond the point of balance, is doubtless of value to the social group of which they are members, but the increase in stock which tends to general over-mentalization is a dangerous factor.
The underdevelopment of mental capacity, even at levels far above feeble-mindedness and other obvious mental defects, is a form of inefficiency as positive as the overdevelopment. We can conceive of a world peopled by a race of men and women of splendid physique, from which the common grades of undesirables have been eliminated: a world in which each individual seems admirably constituted for mating and creating children after his kind. Great content and happiness, and joy in the appreciation of the beauty of their mates, might obtain among this people. Nature too would smile on the race which had so far complied with her conditions. But if this race could attain no further than eminence in the traits we have previously considered, it would be a failure. As a matter of fact, a nation on this plan would have a low chance of survival in conflict and competition with nations which had gone beyond it into a richer mental and spiritual flower and fruition.
If it were possible to apply comprehensive and
