Whichever way it be turned, the reasoning by which this theory of the constant tendency of population to press against the limits of subsistence is supported shows an unwarranted assumption, an undistributed middle, as the logicians would say. Facts do not warrant it, analogy does not countenance it. It is a pure chimera of the imagination, such as those that for a long time prevented men from recognizing the rotundity and motion of the earth. It is just such a theory as that underneath us everything not fastened to the earth must fall off; as that a ball dropped from the mast of a ship in motion must fall behind the mast; as that a live fish placed in a vessel full of water will displace no water. It is as unfounded, if not as grotesque, as an assumption we can imagine Adam might have made had he been of an arithmetical turn of mind and figured on the growth of his first baby from the rate of its early months. From the fact that at birth it weighed ten pounds and in eight months thereafter twenty pounds, he might, with the arithmetical knowledge which some sages have supposed him to possess, have ciphered out a result quite as striking as that of Mr. Malthus; namely, that by the time it got to be ten years old it would be as heavy as an ox, at twelve as heavy as an elephant, and at thirty would weigh no less than 175,716,339,548 tons. The fact is, there is no more reason for us to trouble ourselves about the pressure of population upon subsistence than there was for Adam to worry himself about the rapid growth of his baby. So far as an inference is really warranted by facts and suggested by analogy, it is that the law of population includes such beautiful adaptations as investigation has already shown in other natural laws, and that we are no more warranted in assuming that the instinct of reproduction, in the natural development of society, tends to produce misery and vice, than we should be in assuming that the force of gravitation must hurl the moon to the earth and the earth to the sun, or than in assuming from the contraction of water with reductions of temperature down to thirty-two degrees that rivers and lakes must freeze to the bottom with every frost, and the temperate regions of earth be thus rendered uninhabitable by even moderate winters. That, besides the positive and prudential checks of Malthus, there is a third check which comes into play with the elevation of the standard of comfort and the development of the intellect, is pointed to by many well-known facts. The proportion of births is notoriously greater in new settlements, where the struggle with nature leaves little opportunity for intellectual life, and among the poverty-bound classes of older countries, who in the midst of wealth are deprived of all its advantages and reduced to all but an animal existence, than it is among the classes to whom the increase of wealth has brought independence, leisure, comfort, and a fuller and more varied life.