For what is Montesquieu famous?

Montesquieu is best known for his theory on the separation of powers. This theory has been used to create many constitutions around the world. The idea of this type of government, with the powers separated into branches, was seen in Ancient Rome.

Montesquieu based his model on the Constitution of the Roman Republic and mixed it with the British constitutional system. The philosopher stated that a democracy is principal virtue, which he explained as "the love of the laws and our country." The democracy that he described and built for his theory not only had the separation of powers, but it also has a democratic constitution.