Montesquieu

Montesquieu (Charles Louis de Secondat, baron de La Brede et de Montesquieu, 1689 to 1755) was a French jurist, historian and political philosopher whose 1748 work The Spirit of the Laws set out the modern tripartite division of governmental power into legislative, executive and judicial branches, an arrangement he argued was necessary to prevent the concentration of power and protect political liberty. His formulation drew on earlier ideas, including John Locke's distinction between legislative, executive and federative power, and it went on to shape the design of numerous constitutions, most directly the Constitution of the United States.