We may agree that a natural factor comes into the recent fall in the human birth-rate.

But to argue that because a natural decline in birth-rate is the essential factor in the slowing down of procreative activity with all higher evolution, therefore deliberate birth-control counts for nothing, since exactly the same result follows when voluntary prevention is adopted and when it is not, seems highly absurd.

We must at least admit that voluntary birth-control is an important contributory cause, in some sense indeed, of supreme importance, because it is within man's own power and because man is thus enabled to guide and mould processes of Nature which might otherwise work disastrously.

How disastrously is shown by the history of Europe, and in a notable degree France, during the four or five centuries preceding the end of the eighteenth century when various new influences began to operate.

During all these centuries there was undoubtedly a very high birth-rate, yet infant mortality, war, famine, insanitation, contagious diseases of many and virulent kinds, tended, as far as we can see, to keep the population almost or quite stationary,[30] and so ruinous a method of maintaining a stationary population necessarily used up most of the energy which might otherwise have been available for social progress, although the stationary population, even thus maintained, still placed France at the head of European civilisation.