One of the leading political thinkers of the French Enlightenment, the Baron de Montesquieu (16891755), drew great influence from the works of Locke. Montesquieu’s most critical work, The Spirit of Laws (1748), tackled and elaborated on many of the ideas that Locke had introduced. He stressed the importance of a separation of powers and was one of the first proponents of the idea of a system of checks and balances in government.

Although Montesquieu’s work had a great effect on the development of democracy, Montesquieu himself believed that no one governmental system better than the others but rather that different forms were better than others in certain situations. An early pioneer in sociology, he spent considerable time collecting data from various world cultures, which led him to the rather outlandish conclusion that climate is a major factor in determining the best form of government for a given region. Montesquieu believed that environmental conditions affect behavior and response and thus concluded that governments located in different climates should be adjusted accordingly. Even Montesquieu admitted that this idea worked better in theory than in practice. His legacy therefore lies primarily in his methods, his combination of practicality and Enlightened idealism—ultimately, he was a researcher through and through.


The primary satirist of the Enlightenment, François-Marie Arouet, better known by his pen name Voltaire (16941778), entered the literary world as a playwright. He quickly became renowned for his wit and satire, as well as the libel claims that often resulted. In and out of prison and other various predicaments for most of his young life, Voltaire spent a period of exile in England during which he was introduced to the works of Locke and Newton. The two thinkers had a profound impact on the young Voltaire, who became wildly prolific in the years that followed, authoring more than sixty plays and novels and countless other letters and poems.

Voltaire was an avowed deist, believing in God but hating organized religion. As a result, he made Christianity—which he called “glorified superstition”—a frequent target of his wit. Voltaire was also an ardent supporter of monarchy and spent a considerable amount of time working toward judicial reform. Later, after bouncing around to various countries and working with a number of notable contemporaries, Voltaire wrote the satire Candide (1759), which has since earned distinction as one of the most influential literary works in history.

Although Voltaire lacked the practical breadth of some of his contemporaries—he did not dabble in multiple scientific fields—he made up for it with the volume of his work. Using his brilliant, sarcastic wit to analyze everything from philosophy to politics to law, he extolled the virtue of reason over superstition and intolerance and effectively became the voice of the Enlightenment. Moreover, his satirical style enabled him to make incredibly pointed criticisms while generally avoiding serious prosecution by those he attacked. Although detractors complain that Voltaire never offered any solutions to the problems he criticized, he never aspired to do so. Nonetheless, by merely pointing out problems and criticizing different philosophies, he caused considerable change.


The third major figure of the French Enlightenment was Denis Diderot (17131784), a writer and philosopher best known for editing and assembling the massive Encyclopédie, an attempt to collect virtually all of human knowledge gathered in various fields up to that point. Twenty-eight volumes in length—seventeen text, eleven illustrated—the portion of the Encyclopédie edited by Diderot was published one volume at a time from 1751 to 1772. Diderot, assisted by French mathematician Jean Le Rond d’Alembert for part of the project, painstakingly collected as much Enlightenment-era knowledge as he possibly could. After Diderot’s involvement, an additional seven volumes were completed, but Diderot himself did not edit them.

Popular pages: The Enlightenment (1650–1800)