Charles Louis de Montesquieu wrote The Spirit of the Laws, the book on which the constitutional thinking of Europe and America was built. The separation of powers — legislative, executive, judicial — was his idea.
He was born at La Brede, in Guyenne, in 1689, and served as president of the parlement of Bordeaux. The Persian Letters (1721) satirised French manners through the eyes of invented Persians.
The Spirit of the Laws (1748) argued that laws depend on climate, geography, religion and custom. Liberty is not anarchy but the protection of law; despotism is what happens when everything rests in one pair of hands.
The American Founding Fathers cited him more often than anyone else. He died in Paris in 1755.