What key concept did Charles-Louis Montesquieu promote in relation to government structure?

Charles-Louis Montesquieu is most well-known for promoting the concept of the separation of powers in government. This idea is foundational in political theory and suggests that the powers of government should be divided into distinct branches to prevent any one branch from becoming too powerful. Montesquieu argued that a government should ideally have separate legislative, executive, and judicial branches, each functioning independently yet with the ability to check and balance one another.

This structure serves to enhance the rule of law and protect individual liberties by ensuring that power is distributed rather than concentrated. Montesquieu's work laid the groundwork for many modern democratic systems, particularly influencing the framers of the United States Constitution, who incorporated the separation of powers into their governmental framework.

While checks and balances relates closely to his ideas—referring specifically to the tools each branch has to monitor and limit the actions of the others—the core concept he promoted was primarily the separation of powers itself. In contrast, concepts such as the divine right of kings and social contract theory focus on different aspects of political philosophy and governance that do not directly align with Montesquieu’s advocacy for a structured government system.