•Separation of powers
•identified three sorts of governmental power: legislative, executive and judiciary.
•believed that if one person or group of people held any two or all three of these powers, it would result in “tyrannical laws” executed in a “tyrannical manner.”
•Constitutional monarchy
•did not believe that democracy was the best form of government.
•instead, he favored a constitutional monarchy based on the British model.
spirit of the laws
Frontspiece to The Spirit of the Laws
Montesquieu identified three sorts of governmental power: legislative, executive “in respect to things dependent on the law of nations,” and executive “in regard to those things that depend on civil law” (i.e., the judiciary). Montesquieu believed that if one person or group of people held any two or all three of these powers, it would result in “tyrannical laws” executed in a “tyrannical manner.” His ideas here provided the basis for the doctrine known as “separation of powers,” which significantly influenced the framers of the U.S. Constitution and thus the shaping of the American government.

Montesquieu did not believe that democracy was the best form of government. Instead, he favored a constitutional monarchy based on the British model. He greatly admired Britain’s government because he felt that Parliament, the king, and the courts worked separately and efficiently since each could limit the power of the other. This idea of the different branches of government each preventing the others from obtaining too much power later led to the theory of “checks and balances,” which also influenced the framers of the U.S. Constitution.