If a society does not concur in this plan of reciprocal industry, their numbers will cease to increase; because the industrious will not feed the idle. This I call a state of a moral impossibility of increase in numbers, and I distinguish it from the physical impossibility, which can take place only when nature itself, not man, refuses to produce subsistence. From this I apply to each particular society what I had before found applicable to mankind in general; to wit, That the inhabitants of every country must be in the compound proportion of the quantity of food produced in it, and of the industry of the lower classes. If the food produced surpass the proportion of industry, the balance of food will be exported; if the industry surpasses the proportion of food, its deficiency must be supplied by imports. Reciprocal wants excite to labour; consequently, those whose labour is not directed towards the cultivation of the soil, must live upon a surplus produced by those who do. This divides the society into two classes. The one I call farmers, the other free hands. As the creating these reciprocal wants was what set the society to work, and distributed them naturally into the two classes we have mentioned; so the augmentation of wants will require an augmentation of free hands, and their demand for food will increase agriculture. [Sidenote: CHAP. VI.] Here I define luxury to mean no more than the consumption of superfluity, or the supplying of wants not essentially necessary to life; and, I say, that a taste for superfluity will introduce the use of money, which I represent as the general object of want, that is of desire, among mankind; and I shew how an eagerness to acquire it becomes an universal passion, a means of increasing industry among the free hands; consequently, of augmenting their numbers; consequently, of promoting agriculture for their subsistence. The whole operation I have been describing proceeds upon one supposition, to wit, that the people have a taste for labour, and the rich for superfluity. If these be covetous and admirers of simplicity; or those be lazy and void of ambition, the principles laid down will have no effect: and so in fact we find, that it is not in the finest countries in the world where most inhabitants are found, but in the most industrious. Let it therefore never be said, there are too many manufacturers in a free country. It is the same thing as if it was said, there are too few idle persons, too few beggars, and too many husbandmen. [Sidenote: CHAP. VII.] Here I break off my subject, to answer an objection arising from these principles. OBJ. How could the simplicity of the antients be compatible with a great multiplication?