Step 1: Understanding the Concept:
Separation of powers is a political doctrine which advocates that the three branches of government (Legislature, Executive, and Judiciary) should be kept separate and distinct.
Step 2: Detailed Explanation:
The French philosopher Baron de Montesquieu articulated this theory in his 1748 work, "The Spirit of the Laws" (\textit{De l'esprit des lois}).
He argued that dividing government power prevents any one branch from becoming too powerful, thereby protecting individual liberty and preventing tyranny.
- John Locke influenced the idea of natural rights and a social contract, but Montesquieu developed the specific framework for tripartite separation.
- Rousseau is known for the "General Will" and Marx for "Historical Materialism".
Step 3: Final Answer:
The concept is most closely associated with Montesquieu.