  In monarchies, Montesquieu believes, the aim of commerce is, for the most part, to supply luxuries. In republics, it is to bring from one country what is wanted in another, "gaining little" but "gaining incessantly" (SL 20.4). In despotisms, there is very little commerce of any kind, since there is no security of property. In a monarchy, neither kings nor nobles should engage in commerce, since this would risk concentrating too much power in their hands. By the same token, there should be no banks in a monarchy, since a treasure "no sooner becomes great than it becomes the treasure of the prince" (SL 20.10). In republics, by contrast, banks are extremely useful, and anyone should be allowed to engage in trade. Restrictions on which profession a person can follow destroy people's hopes of bettering their situation; they are therefore appropriate only to despotic states.