Which thinker advocated for the separation of government powers into different branches?

Montesquieu is recognized for his significant contribution to political theory through his advocacy for the separation of powers within government. In his work "The Spirit of the Laws," Montesquieu argued that political authority should be divided among different branches — typically the executive, legislative, and judicial branches. This framework was designed to prevent any single entity from gaining too much power, thereby safeguarding individual liberties and promoting governmental accountability.

His ideas greatly influenced modern democratic systems, including the structure of the United States government, emphasizing checks and balances that are integral to maintaining a fair and just society. This concept has been pivotal in the development of constitutional frameworks around the world, underscoring the importance of separating powers to enhance democracy and prevent tyranny.