Everything in the world is purchased by labour, and our passions are the only causes of labour. When a nation abounds in manufactures and mechanic arts, the proprietors of land, as well as the farmers, study agriculture as a science, and redouble their industry and attention. The superfluity which arises from their labour is not lost, but is exchanged with the manufacturers for those commodities which men’s luxury now makes them covet. By this means land furnishes a great deal more of the necessaries of life than what suffices for those who cultivate it. In times of peace and tranquillity this superfluity goes to the maintenance of manufacturers, and the improvers of liberal arts. But it is easy for the public to convert many of these manufacturers into soldiers, and maintain them by that superfluity which arises from the labour of the farmers. Accordingly we find that this is the case in all civilized governments. When the sovereign raises an army, what is the consequence? He imposes a tax. This tax obliges all the people to retrench what is least necessary to their subsistence. Those who labour in such commodities must either enlist in the troops or turn themselves to agriculture, and thereby oblige some labourers to enlist for want of business. And to consider the matter abstractly, manufactures increase the power of the state only as they store up so much labour, and that of a kind to which the public may lay claim, without depriving any one of the necessaries of life. The more labour, therefore, is employed beyond mere necessaries, the more powerful is any state; since the persons engaged in that labour may easily be converted to the public service. In a state without manufactures there may be the same number of hands; but there is not the same quantity of labour, nor of the same kind. All the labour is there bestowed upon necessaries, which can admit of little or no abatement. Thus the greatness of the sovereign and the happiness of the state are, in a great measure, united with regard to trade and manufactures. It is a violent method, and in most cases impracticable, to oblige the labourer to toil in order to raise from the land more than what subsists himself and family. Furnish him with manufactures and commodities, and he will do it of himself. Afterwards you will find it easy to seize some part of his superfluous labour, and employ it in the public service, without giving him his wonted return. Being accustomed to industry, he will think this less grievous than if, at once, you obliged him to an augmentation of labour without any reward. The case is the same with regard to the other members of the state. The greater is the stock of labour of all kinds, the greater quantity may be taken from the heap without making any sensible alteration upon it.