The increase of domestic industry lays the foundation of foreign commerce. Where a great number of commodities are raised and perfected for the home-market there will always be found some which can be exported with advantage. But if our neighbours have no art nor cultivation, they cannot take them, because they will have nothing to give in exchange. In this respect, states are in the same condition as individuals. A single man can scarce be industrious where all his fellow-citizens are idle. The riches of the several members of a community contribute to increase my riches, whatever profession I may follow. They consume the produce of my industry, and afford me the produce of theirs in return. Nor need any state entertain apprehensions that their neighbours will improve to such a degree in every art and manufacture as to have no demand from them. Nature, by giving a diversity of geniuses, climates, and soils to different nations, has secured their mutual intercourse and commerce, as long as they all remain industrious and civilized. Nay, the more the arts increase in any state, the more will be its demands from its industrious neighbours. The inhabitants, having become opulent and skilful, desire to have every commodity in the utmost perfection; and as they have plenty of commodities to give in exchange, they make large importations from every foreign country. The industry of the nations from whom they import receives encouragement; their own is also increased by the sale of the commodities which they give in exchange.