  While some mercantilists had argued that commerce is a zero-sum game in which when some gain, others necessarily lose, Montesquieu believes that commerce benefits all countries except those who have nothing but their land and what it produces. In those deeply impoverished countries, commerce with other countries will encourage those who own the land to oppress those who work it, rather than encouraging the development of domestic industries and manufacture. However, all other countries benefit by commerce, and should seek to trade with as many other nations as possible, "for it is competition which sets a just value on merchandise, and establishes the relation between them" (SL 20.9).