Vom Geist der Gesetze
The third major contribution of "The Spirit of the Laws" was to the field of political sociology, which Montesquieu is often credited with more or less inventing. The bulk of the treatise, in fact, concerns how geography and climate interact with particular cultures to produce the spirit of a people. This spirit, in turn, inclines that people toward certain sorts of political and social institutions, and away from others. Later writers often caricatured Montesquieu's theory by suggesting that he claimed to explain legal variation simply by the distance of a community from the equator.