Montesquieu

Known for

Separation of powers, The Spirit of the Laws

Thought

Montesquieu argued that liberty is best protected not by virtuous rulers but by structure: dividing government into separate legislative, executive and judicial branches, each able to check the others, so no single branch can accumulate tyrannical power. This separation of powers became a direct model for the US Constitution's system of checks and balances.

Biography

French judge and political thinker whose observations of the English constitution, formed during a stay in England, shaped his most influential work.

Major works

• The Spirit of the Laws
• Persian Letters