Charles-Louis de Secondat, Baron de La Brède et de Montesquieu, referred to in history as simply Montesquieu, was a French philosopher who lived during the European Age of Enlightenment, in the 17th and 18th centuries. His writings and his political ideas were read by many American colonists and founders and had a profound influence on the shaping of the U.S. Constitution.

Background

Montesquieu lived from 1689 to 1755 during the European Age of Enlightenment, also known as the Age of Reason, a cultural movement during the 17th and 18th centuries that emphasized rationality and individualism. Montesquieu's most famous work was The Spirit of the Laws, the work of political philosophy from which his most influential ideas were drawn.

Separation of Powers

Montesquieu's oft-cited contribution to political discourse is his theory on the separation of powers between the legislative, executive and judicial branches, which became the bedrock of the U.S. Constitution and the way the founders envisioned a plan that would divide and thus balance the powers of the new government. Montesquieu based his thinking on the republican government of the ancient Romans and on the parliamentary monarchy of Britain at the time. These governments, he argued, prevented the concentration of power in one person's hands and the infringement upon individual liberties that come with dictatorial governments.

Checks and Balances

A related idea of Montesquieu's was that of checks and balances, or the notion that each branch of government should have a way to curtail the power of the other so that no one is superior. This idea is embedded in the Constitution in many ways: The executive branch can check the power of the legislature through the veto while the legislative branch can check the executive through impeachment, to name two examples

Other Enlightenment Influences

Montesquieu was but one of many Enlightenment influences on the Constitution, many of whom were also influences on Montesquieu himself. John Locke, the English philosopher, wrote Two Treatises on Government in 1689, a work which not only influenced the American founding fathers, but also Montesquieu himself, as many of Locke's ideas of natural rights to life, liberty, property and happiness found their way into the Constitution and into The Spirit of the Laws.