Montesquieu
To prevent abuse, power must check power.
Montesquieu (1689 – 1755, France) : enlightenment and liberalism. Laws do not fall from the sky at random: they have causes. Climate, religion, customs, trade and the form of government make up the "spirit" of a nation, and a good law must suit it. On AskPhilosophy: 4 reconstructed arguments, 7 quotes checked word for word against the original texts, and 3 common beliefs examined; every text carries an authenticity badge (written by the author, posthumous, student notes, reported, apocryphal).
Why he matters
The framers of the American Constitution (1787) quote him constantly: his idea of one power limiting another is at the heart of almost every modern constitution. He is also a founder of sociology: he looks for the causes of laws instead of only judging them. His Persian Letters invent a foreign gaze to show the French their own oddities.
His times
Baron of La Brède and président à mortier in the Parlement of Bordeaux, a senior judge. He sold his office to travel in Europe (1728-1731) and stayed almost two years in England. His two great books appeared without his name, but everyone knew they were his. The Church put The Spirit of the Laws on the Index in 1751.
His positions
click a row to see the evidenceHe posits a creating and preserving God who acts by rules, and finds it absurd that a "blind fatality" produced intelligent beings. A deist for many readers, a moderate Catholic for others: he defends religion mainly for its political usefulness, and his books on religion are not yet in our corpus.
His method starts from observation: he examines the laws and customs of all peoples before laying down principles. But he also believes in necessary relations that reason grasps, as in geometry.
He thinks he has found principles from which particular cases follow "as of themselves". Yet he stays cautious: he will reform nothing without knowing the whole constitution of a state.
He does not address the question in our texts. He believes in a soul, but describes at length how the body and climate (the "fibres") act on character: a period physiology, now outdated.
Intelligent beings "act of themselves": that is why they can disobey laws. Climate pushes people but does not doom them: good legislators fight its effects.
There are relations of justice before any written law. Saying that nothing is just or unjust without the law is saying that before a circle was drawn its radii were not equal.
He studies religions as an observer, by their effects on laws and customs. In the Persian Letters, Usbek holds that even without God we would have to love justice: morality does not depend on faith.
He does not ask the question directly. He only says he would be "the most happy of mortals" if he could cure people of their prejudices.
Man is a "flexible being" who bends to the ideas of others. He is neither good nor bad by nature, but whoever has power tends to abuse it: so limits are needed, even for virtue.
Political liberty is security: not having to fear another citizen. But it is not doing what one likes: it is doing what the laws permit. He also cares a great deal about intermediate bodies (nobility, parlements) and the customs of each people.
A natural-law ethics: justice is a "relation of fitness" between things, as real as a geometrical relation, which human laws must follow.