“The gain of the merchants, it is said, is not always the gain of the country in general. If, for instance, a merchant imports foreign goods by which the consumption of national manufactures is hurt, though the merchant should be gainer by those goods, the State is a loser. As, on the other hand, a merchant may export the manufactures of his own country to his own loss and the nation’s gain. But if the merchants be gainers, the consumers, that is those for whose use manufactures are established, having a power of purchasing or not at pleasure, must be so too. And if, after sufficient trial, it be found that merchants importing foreign goods can sell these cheaper than the manufactures can be bought at home, it is an indication that it is not for the interest of the nation at large to encourage such manufactures. “Though exportation makes a nation rich, we are not to judge of the quantity of riches which a nation gains by trade from exportation only, but the importation must also be considered. If these exactly balance one another nothing can be said to be gained or lost, just as a person is not the richer for selling a quantity of goods if he buy to the same amount. Nay, though the exportation be lessened, if the importation be lessened more than in proportion, it proves an increase of gainful trade, notwithstanding the decrease of exportation. This, however, is estimating the value of commerce by the mere increase of money. But a nation may flourish by internal commerce only, and what is _external_ commerce between two nations not united in government would be internal if they should come under the same government. In every fair bargain the buyer and the seller are equally gainers, whether money be accumulated by either of the parties or not. “It is a great mistake to confound the king’s revenue with the gain a nation makes by its trade. No man would presume to say it is more for the public benefit that the nation should expend a million or more every year with foreigners, in order to raise a hundred thousand pounds to the revenue by the customs, than to save that million or more within ourselves and to raise only the hundred thousand pounds the other way. But Ministers of State are apt to estimate the value of everything to the country by the gain it brings, and that immediately to themselves.... “The legislature of any country has seldom interfered in the affairs of commerce, but commerce has suffered in consequence to it, owing to the ignorance of statesmen, and even of merchants themselves, concerning the nature of trade. And indeed the principles of commerce are very complicated and require long experience and deep reflection before they can be well understood....