It has always been so. Behind all war has been the pressure of population. "Historians," says Huxley, "point to the greed and ambition of rulers, the reckless turbulence of the ruled, to the debasing effects of wealth and luxury, and to the devastating wars which have formed a great part of the occupation of mankind, as the causes of the decay of states and the foundering of old civilizations, and thereby point their story with a moral. But beneath all this superficial turmoil lay the deep-seated impulse given by unlimited multiplication." Robert Thomas Malthus, formulator of the doctrine which bears his name, pointed out, in the closing years of the eighteenth century, the relation of overpopulation to war. He showed that mankind tends to increase faster than the food supply. He demonstrated that were it not for the more common diseases, for plague, famine, floods and wars, human beings would crowd each other to such an extent that the misery would be even greater than it now is. These he described as "natural checks," pointing out that as long as no other checks are employed, such disasters are unavoidable. If we do not exercise sufficient judgment to regulate the birth rate, we encounter disease, starvation and war. Both Darwin and John Stuart Mill recognized, by inference at least, the fact that so-called "natural checks"--and among them war--will operate if some sort of limitation is not employed. In his _Origin of Species_, Darwin says: "There is no exception to the rule that every organic being naturally increases at so high a rate, if not destroyed, that the earth would soon be covered by the progeny of a single pair." Elsewhere he observes that we do not permit helpless human beings to die off, but we create philanthropies and charities, build asylums and hospitals and keep the medical profession busy preserving those who could not otherwise survive. John Stuart Mill, supporting the views of Malthus, speaks to exactly the same effect in regard to the multiplying power of organic beings, among them humanity. In other words, let countries become overpopulated and war is inevitable. It follows as daylight follows the sunrise. When Charles Bradlaugh and Mrs. Annie Besant were on trial in England in 1877 for publishing information concerning contraceptives, Mrs. Besant put the case bluntly to the court and the jury: