before our minds the vital questions of human fecundity, and of the ability of the earth to sustain its increasing multitude of human inhabitants. But in reading the statistics of this subject our interest in it redoubles. When we find men in all nations and in all ages pressing sharply on the means of subsistence, the loss by famine quickly replaced by new food for famine, the ravages of war and pestilence rapidly obliterated by new-growing populations, and apparently nothing but the pressure of sheer want and misery able to limit human fecundity, we may well question if this is to be the continued destiny of mankind, and if there is no possible limit to population within this sharp boundary of distress.
Nearly a century has elapsed since Malthus published his disheartening researches on this subject, and his conclusions yet remain only in part refuted. If it really be, as he declares, that population tends to increase in a geometrical ratio, while the food-supply increases only in an arithmetical ratio, his conclusion, that population has a constant tendency to run ahead of subsistence, seems inevitable. Fortunately, however, his hypothesis, so far, has been proved only by arguments, not by irrefutable facts. The numbers of mankind, it is true, have frequently passed the boundary which divides want from plenty. But the other requirement of the Malthusian doctrine was not, in those cases, attained. Food-production has never yet reached its limit, and the suffering so far caused by want of food might have been entirely obviated had the earth been fully cultivated. It may, however, be claimed by disciples of Malthus that this fact has nothing to do with the question, and that, when the utmost food-production has been attained, population will still press beyond it to the starvation limit. This argument we venture to dispute. The attainment of a great food-production introduces certain conditions into the problem which may give it an entirely different aspect. Such excessive production will require, for instance, a marked advance in human intelligence, and the replacement of much of the muscular labor of mankind by an active mental labor. It is our purpose to consider what effect this changed condition of the human race will have upon the increase of population. It is easy to point to modern instances in which the rapid increase of population has been checked without special exercise of the starvation influence. The population of France, for instance, has been almost stationary for many years, its increase being much below the corresponding increase of wealth in that country. Thus France furnishes a practical argument against the Malthusian hypothesis, and shows that the growth of population may decline from other causes than vice, misery, and disease.
There exist, in fact, three separate checks to the increase of population. These may be here classed as the physical, the mental, and the physiological. The first and second of these have been fully considered by writers on political economy. The third has been barely
