Montesquieu's Critique Of Southern Climates

Montesquieu believed that a region’s climate had a deep impact on the intelligence and physiology of that region’s inhabitants. Though “northern” and “temperate” climates face some critique, it is the southern climates (Africa, the Caribbean, etc.) which Montesquieu is most critical of: “If we draw near the South, we fancy ourselves entirely removed from the verge of morality; here the strongest passions are productive of all manner of crimes, each man endeavoring, let the means be what they will, to indulge his inordinate desires” (14.2). Montesquieu believes that those who inhabit southern climates are almost entirely moved by the passions, and that they lack reason. However, this is not to say that climate is entirely deterministic: the machine that is man can be driven towards reason by legislators who “pass laws to promote virtue and discourage vice.” It is also this critique of southern constitutions that allows Montesquieu to entertain the idea that, under certain circumstances, slavery may be based on some form of “natural reason.” Montesquieu explains that:
Aristotle endeavors to prove that there are natural slaves; but what he says is far from proving it. If there be any such, I believe they are those of whom I have been speaking. But as all men are born equal, slavery must be accounted unnatural, though in some countries it be founded on natural reason; and a wide difference ought to be made between such countries, and those in which even natural reason rejects it, as in Europe, where it has been so happily abolished.