Section 7. OVERPOPULATION IN THE FUTURE

It is a fallacy to say that overpopulation is the cause of poverty and disease, and that for the simple reason that overpopulation has not yet occurred. For the growth of a nation we assume that the birth-rate should exceed the death-rate by from 10 to 20 per thousand, and it is obvious that in a closed country the evil of overpopulation might appear in a comparatively short time. The natural remedies in the past have been emigration and colonisation. According to the birth controllers these remedies are only temporary, because sooner or later all colonies and eventually the earth itself will be overpopulated. At the British Association Meeting in 1890 the population of the earth was said to be 1,500 millions, and it was calculated that only 6,000 millions could live on the earth. This means that if the birth-rate throughout the world exceeded the death-rate by only 8 per thousand, the earth would be overpopulated within 200 years. It is probable that in these calculations the capacity of the earth to sustain human life has been underestimated; that the earth could support not four times but sixteen times its present population; and that the latter figure could be still further increased by the progress of inventions. But, apart altogether from the accuracy of these figures, the danger of overpopulation is nothing more or less than a myth. Indeed, the end of the world, a philosophic and scientific certitude, is a more imminent event than its overpopulation.

Section 8. HOW NATIONS HAVE PERISHED

Before speculating on what might happen in the future, it is well to recollect what has happened in the past. The earth has been inhabited for thousands of years, and modern research has revealed the remains of many ancient civilisations that have perished. For example, there were the great nations of Cambodia and of Guatemala. In Crete, about 2000 B.C., there existed a civilisation where women were dressed as are this evening the women of London and Paris. That civilisation perished, and even its language cannot now be deciphered. Why did these civilisations perish? Surely this momentous question should take precedence over barren discussions as to whether there will be sufficient food on the land or in the sea for the inhabitants of the world in 200 years' time. How came it about that these ancient nations did not double their numbers every fifty years and fill up the earth long ago?

The answer is that they were overcome and annihilated by the incidence of one or other of two dangers that threaten every civilisation, including our own. These dangers are certain physical and moral catastrophes, against which there is only one form of natural insurance, namely, a birth-rate that adequately exceeds the death-rate. They help to illustrate further the fallacy of the overpopulation scare.

The following is a general outline of these dangers, and in a later chapter (p. 70)(see [Reference: Dangers]) I shall quote an example of how they have operated in the past.

Section 9. PHYSICAL CATASTROPHES

Deaths from famine, floods, earthquakes, and volcanic eruptions are confined to comparatively small areas, and the two physical catastrophes that may seriously threaten a civilisation may be reduced to endemic disease and war.

(a) Disease

Disease, in the form of malaria, contributed to the fall of ancient Greece and Rome. In the fourteenth century 25,000,000 people, one-quarter of the population of Europe, were exterminated by plague, the "Black Death," and in the sixteenth century smallpox depopulated Spanish America. Although these particular diseases have lost much of their power owing to the progress of medical science, we have no right to assume that disease in general has been conquered by our civilisation, or that a new pestilence may not appear. On the contrary, in 1805, a new disease, spotted fever, appeared in Geneva, and within half a century had become endemic throughout Europe and America. Of this fever during the Great War the late Sir William Osler wrote: "In cerebro-spinal fever we may be witnessing the struggle of a new disease to win a place among the great epidemics of the world." There was a mystery about this disease, because, although unknown in the Arctic Circle, it appeared in temperate climates during the coldest months of the year. As I was able to prove in 1915, [8] it is a disease of civilisation. I found that the causal organism was killed in thirty minutes by a temperature of 62°F. It was thus obvious that infection could never be carried by cold air. But in overcrowded rooms where windows are closed, and the temperature of warm, impure, saturated air was raised by the natural heat of the body to 80°F or over, the life of the microorganism, expelled from the mouths of infected people during the act of coughing, was prolonged. Infection is thus carried from one person to another by warm currents of moving air, and at the same time resistance against the disease is lowered. Cold air kills the organism, but cold weather favours the disease. In that paradox the aetiology of cerebro-spinal fever became as clear as the means of prevention. The story of spotted fever reveals the forces of nature fighting against the disease at every turn, and implacably opposed to its existence, while man alone, of his own will and folly, harbours infection and creates the only conditions under which the malady can appear. For example, during two consecutive winters cerebro-spinal fever had appeared in barracks capable of housing 2,000 men. A simple and effective method of ventilation was then introduced. From that day to this not a single case of cerebro-spinal fever has occurred in these barracks, although there have been outbreaks of this disease in the town in which the barracks are situated.