We have already had occasion to remark that industry and commerce were considered unproductive. This was a most significant fact, so far as commerce was concerned, because all the theories that held the field under Mercantilism, notably the doctrine that foreign commerce afforded the only possible means of increasing a country’s wealth, immediately assumed a dwindling importance. For the Mercantilists the prototype of the State was a rich merchant of Amsterdam. For the Physiocrats it was John Bull. And foreign trade, like domestic, produced no real wealth: the only result was a possible gain, and one man’s gain is another man’s loss. “Every commercial nation flatters itself upon its growing wealth as the outcome of foreign trade. This is a truly astonishing phenomenon, for they all believe that they are growing rich and gaining from one another. It must be admitted that this gain, as they call it, is a most remarkable thing, for they all gain and none loses.”[62] A country must, of course, obtain from foreigners the goods which it cannot itself produce in exchange for those it cannot itself consume. Foreign trade is quite indispensable, but Mercier de la Rivière thinks that it is a necessary evil[63] (he underlines the word). Quesnay contents himself with referring to it merely as a _pis aller_.[64] He thought that the only really useful exchange is one in which agricultural products pass directly from producers to consumers, for without this the products would be useless and would simply perish in the producer’s hands. But that kind of exchange which consists in buying products in order to resell them—trafficking, or a commercial transaction, as we call it—is sheer waste, for the wealth instead of growing larger becomes less, because a portion of it is absorbed by the traffickers themselves.[65] We meet with the same idea in Carey. Mercier de la Rivière ingeniously compares such traders to mirrors, arranged in such a way that they reflect a number of things at the same time, all in different positions. “Like mirrors, too, the traders seem to multiply commodities, but they only deceive the superficial.”[66] That may be; but, admitting a contempt for commerce, what conclusions do they draw from it? Shall they prohibit it, or regulate it, or shall they just let it take its own course? Any one of these conclusions would follow from their premises. If commerce be as useless as they tried to make out, the first solution would be the best. But it was the third that they were inclined to adopt, and we must see why.