When we treat of a virtuous people applying to trade and industry, let us consider their _interest_ only, in preserving those sentiments; and examine the political evil of their falling off from them. When we treat of a luxurious nation, where the not-working part is given to excesses in all kinds of consumption, and the working part to labour and ingenuity, in order to supply them, let us examine the consequences of such a spirit, with respect to foreign trade: and if we find, that a luxurious turn in the rich is prejudicial thereto, let us try to discover the methods of engaging the inhabitants to correct their manners from a motive of self-interest. These things premised, I shall now give a short sketch of the general principles upon which a system of foreign trade may be established and preserved as long as possible, and of the methods by which it may be again recovered, when, from the natural advantages and superior ability of administration in rival nations, (not from vices at home) a people have lost for a time every advantage they used to draw from their foreign commerce. The first general principle is to employ, as usefully as possible, a certain number of the society, in producing objects of the first necessity, always more than sufficient to supply the inhabitants; and to contrive means of enabling every one of the free hands to procure subsistence for himself, by the exercise of some species of industry. These first objects compassed, I consider the people as abundantly provided with what is purely necessary; and also with a surplus prepared for an additional number of free hands, so soon as a demand can be procured for their labour. In the mean time, the surplus will be an article of exportation; but no sooner will demand come from abroad, for a greater quantity of manufactures than formerly, than such demand will have the effect of gradually multiplying the inhabitants up to the proportion of the surplus above mentioned, provided the statesman be all along careful to employ these additional numbers, which an useful multiplication must produce, in supplying the additional demand: then with the equivalent they receive from strangers, they will at the same time enrich the country, and purchase for themselves that part of the national productions which had been permitted to be exported, only for want of a demand for it at home. He must, at the same time, continue to give proper encouragement to the advancement of agriculture, that there may be constantly found a surplus of subsistence (for without a surplus there can never be enough) this must be allowed to go abroad, and ought to be considered as the provision of those industrious hands which are yet unborn.