(1) The limitation of population by the restriction of the means of subsistence.

(2) The invariable increase of population whenever the means of subsistence increase, unless prevented by powerful checks.

(3) The factors which keep population on a level with the means of subsistence are all resolvable into three: moral restraint, vice, and misery.[XII-7]

No one can gainsay the importance or the seriousness of the problem of population. Plato wrestled with it, and urged that procreation when it goes on too fast or too slow should be regulated by the state—through a proper distribution of marks of ignominy or of honor. The number of marriages should be determined by the magistrates.

Aristotle suggested that the ages of marriage for both sexes should be regulated; he even advocated the regulation of the number of children for each marriage. Additional children should be aborted.

Malthus, however, was wiser than either Plato or Aristotle, for he observed that the cause which has the most lasting effect in improving the condition of the poorer classes is the conduct and prudence of the individuals themselves.[XII-8] Malthus asserted that it is in the power of each individual to avoid all the evil consequences to himself and society which result from the principle of population, “by the practice of a virtue clearly dictated to him by the light of nature and expressly enjoined in revealed religion.”[XII-9]

Malthus demonstrated clearly the weakness of liberal poor-laws. Give more food to the poor, and they will produce more children, and suffer more misery. Poor-laws increase the numbers of children of the poor, and hence increase the amount of misery. Both private benevolence and poor-laws increase the number of marriages and of children.[XII-10]

Education is the solution which Malthus demanded.[XII-11] Educate the poor to postpone marriage, to keep the birth rate down, and to practice economic thrift. To a great extent education will secure the operation of the prudential check upon population. The science of moral and political philosophy should not be confined within such narrow limits that it is unable to overcome in practical ways the obstacles to human happiness which arise from the law of population.[XII-12]

There are factors in the population situation which did not exist at the time of Malthus, or which he did not see. Today there are additional preventive checks upon population, for example, the rise of democracy in the family whereby the wife and mother no longer is dominated by the husband and father, but has a voice of her own regarding domestic matters, such as the number of children. Closely related to this tendency is the feminist movement, or woman’s rights movement, whereby women are demanding that they not be confined to the sphere of bearing and rearing children. Increasing intelligence and foresight has served as a powerful preventive check upon population. The current emphasis upon luxury is inimical to the birth rate. A higher economic status almost uniformly cuts down the birth rate. Within the last score of years the new science of eugenics has attracted widespread attention. Eugenics stresses quality of population. It would effect a decrease in the numbers of children born among the lower classes, among the poorer stocks, and prevent procreation among the mentally deficient. It would increase the birth rate among the cultured and the high grade stocks.

Malthus appreciated the dependence of urban population upon rural districts, but he could not foresee the degree to which cities would grow in the nineteenth and twentieth centuries. The relative decrease of agricultural labor and the proportional increase in non-agricultural labor has thrown a burden upon the food supply which even Malthus could not forecast.