<Dd> Montesquieu intends what modern legal scholars might call the rights to "robust procedural due process", including the right to a fair trial, the presumption of innocence and the proportionality in the severity of punishment . Pursuant to this requirement to frame civil and criminal laws appropriately to ensure political liberty (i.e., personal security), Montesquieu also argues against slavery and for the freedom of thought, speech and assembly . </Dd> <P> This book concerns explicit laws, not in unwritten cultural norms that may support the same goals . "Montesquieu believed the hard architecture of political institutions might be enough to constrain overreaching power--that constitutional deign was not unlike an engineering problem," as Levitsky and Ziblatt put it . </P> <P> The third major contribution of De l'esprit des lois 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 . </P> <P> While the analysis in De l'esprit des lois is much more subtle than these later writers perceive, many of his specific claims lack rigour to modern readers . Nevertheless, his approach to politics from a naturalistic or scientific point of view proved very influential, directly or indirectly inspiring modern fields of political science, sociology, and anthropology . </P>

Who was the spirit of laws written for