If, therefore, according to modern oeconomy, the lowest species of labour must be kept cheap, in order to make manufactures flourish, the state must be at the expence of the children; for as matters stand, either the unmarried gain as much as the married should do, and become extravagant; or the married gain no more than the unmarried can do, and become miserable. An unequal competition between people of the same class, always implies one of these inconveniencies; and from these principally proceeds the decay and misery of such numbers in all modern states, as well as the constant complaints of the augmentation of the price of labour. Every individual is equally inspired with a desire to propagate. A people can no more remain without propagating, than a tree without growing: but no more can live than can be fed; and as all augmentations of food must come at last to a stop, so soon as this happens, a people increase no more; that is to say, the proportion of those who die annually increases. This insensibly deters from propagation, because we are rational creatures. But still there are some who, though rational, are not provident; these marry and produce. This I call vicious propagation. Hence I distinguish propagation into two branches, to wit, multiplication, which goes on among these who can feed what they breed, and mere procreation, which takes place among those who cannot maintain their offspring. This last produces a political disease, which mortality cures at the expence of much misery; as forest trees which are not pruned, dress themselves and become vigorous at the expence of numbers which die all around. How to propose a remedy for this inconveniency, without laying some restraint upon marriage; how to lay a restraint upon marriage without shocking the spirit of the times, I own I cannot find out; so I leave every one to conjecture. [Sidenote: CHAP. XIII.] Although a complete remedy cannot be obtained against the effects of abusive procreation; yet with the help of accurate lists of births and deaths for every class of people, many expedients may be fallen upon to preserve the few who escape the dangers of their infancy, from falling back into the unhappy class which produced them. From these lists the degree of mortality and nature of diseases, as well as the difference between the propagation of the easy and of the miserable, will plainly appear; and if it be the duty of a statesman to keep all his people busy, he certainly should acquire the most exact knowledge possible of the numbers and propagation of those of every denomination, that he may prevent any class from rising above or sinking below the standard, which is best proportioned to the demand for their respective industry. [Sidenote: CHAP. XIV.]