"My conclusion is that a scientific society can be stable given certain conditions. The first of these is a single government of the whole world, possessing a monopoly of armed force and therefore able to enforce peace. The second condition is a general diffusion of prosperity, so that there is no occasion for envy of one part of the world by another. The third condition (which supposes the second fulfilled) is a low birth rate everywhere, so that the population of the world becomes stationary, or nearly so. The fourth condition is the provision for individual initiative both in work and in play, and the greatest diffusion of power compatible with maintaining the necessary political and economic framework. The world is a long way from realizing these conditions, and therefore we must expect vast upheavals and appalling suffering before stability is attained. But, while upheavals and suffering have hitherto been the lot of man, we can now see, however dimly and uncertainly, a possible future culmination in which poverty and war will have been overcome, and fear, where it survives, will have become pathological. The road, I fear, is long, but that is no reason for losing sight of the ultimate hope."