Populations increase and decrease relatively not only to one another, but also to natural resources. In most parts of the world, the relation between population and resources is already unfavourable and will probably become even more unfavourable in the future. This growing poverty in the midst of growing poverty constitutes a permanent menace to peace. And not only to peace, but also to democratic institutions and personal liberty. For overpopulation is not compatible with freedom. An unfavourable relationship between numbers and resources tends to make the earning of a living almost intolerably difficult. Labour is more abundant than goods, and the individual is compelled to work long hours for little pay. No surplus of accumulated purchasing power stands between him and the tyrannies of unfriendly nature or of the equally unfriendly wielders of political and economic power.

Democracy is, among other things, the ability to say 'no' to the boss. But a man cannot say 'no' to the boss, unless he is sure of being able to eat when the boss's favour has been withdrawn. And he cannot be certain of his next meal unless he owns the means of producing enough wealth, for his family to live on, or has been able to accumulate a surplus out of past wages, or has a chance of moving to virgin territories, where he can make a fresh start. In an overcrowded country, very few people own enough to make them financially independent; very few are in a position to accumulate purchasing power; and there is no free land. Moreover, in any country where population presses hard upon natural resources, the general economic situation is apt to be so precarious that government control of capital and labour, production and consumption, becomes inevitable. It is no accident that the twentieth century should be the century of highly centralized governments and totalitarian dictatorships; it had to be so for the simple reason that the twentieth century is the century of planetary overcrowding.