...regrettable as it may seem to the idealist, the experience of history provides little warrant for the belief that real progress, and the freedom that makes progress possible, lies in unification. For where unification has been able to establish unity of ideas it has usually ended in uniformity, paralysing the growth of new ideas. And where the unification has merely brought about an artificial or imposed unity, its irksomeness has led through discord to disruption.Vitality springs from diversity- which makes for real progress so long as there is mutual toleration, based on the recognition that worse may come from an attempt to suppress differences than from acceptance of them. For this reason, the kind of peace that makes progress possible is best assured by the mutual checks created by a balance of forces- alike in the sphere of internal politics and of international relations.