Those who contend that because of present human cranial size, and the limitations of the human pelvis, man's brain is no longer capable of further expansion, are mistaken. Cranial capacities of almost a third more than the modern average have been occasionally attained among the Boskop people and even in rare individuals among other, less foetalized races. The secret does not lie in the size of the brain before birth; rather, as we have seen, it is contained in that strange spurt which in the first year of life carries man upward and outward into a social world from which his fellow beings are excluded. Whether that postnatal expansion is destined to be further enhanced in the long eras to come there is no telling, nor, perhaps, does it matter greatly. For in the creation of the social brain, nature, through man, has eluded the trap which has engulfed in one way or another every other form of life on the planet. Within the reasonable limits of the brain that now exists, she has placed the long continuity of civilized memory as it lies packed in the world's great libraries. The need is not really for more brains, the need is now for a gentler, a more tolerant people than those who won for us against the ice, the tiger, and the bear. The hand that hefted the ax, out of some old blind allegiance to the past fondles the machine gun as lovingly. It is a habit man will have to break to survive, but the roots go very deep.