Enlightenment, Age of, a term used to describe the trends in thought and letters in Europe and the American colonies during the 18th century prior to the French Revolution. The phrase was frequently employed by writers of the period itself, convinced that they were emerging from centuries of darkness and ignorance into a new age enlightened by reason, science, and a respect for humanity.
The precursors of the Enlightenment can be traced to the 17th century and earlier. They include the philosophical rationalists René Descartes and Baruch Spinoza, the political philosophers Thomas Hobbes and John Locke, and various skeptical thinkers in France such as Pierre Bayle. Equally important, however, were the self-confidence engendered by new discoveries in science and the spirit of cultural relativism encouraged by the exploration of the non-European world.
Of the basic assumptions and beliefs common to philosophers and intellectuals of this period, perhaps the most important was an abiding faith in the power of human reason. The age was enormously impressed by Isaac Newton’s discovery of universal gravitation. If humanity could so unlock the laws of the universe, God’s own laws, why could it not also discover the laws underlying all of nature and society? People came to assume that through a judicious use of reason, an unending progress would be possible—progress in knowledge, in technical achievement, and even in moral values. Following the philosophy of Locke, the 18th-century writers believed that knowledge is not innate, but comes only from experience and observation guided by reason. Through proper education, humanity itself could be altered, its nature changed for the better. A great premium was placed on the discovery of truth through the observation of nature, rather than through the study of authoritative sources, such as Aristotle and the Bible. Although they saw the church—especially the Roman Catholic church—as the principal force that had enslaved the human mind in the past, most Enlightenment thinkers did not renounce religion altogether. They opted rather for a form of Deism, accepting the existence of God and of a hereafter, but rejecting the intricacies of Christian theology. Human aspirations, they believed, should not be centered on the next life, but rather on the means of improving this life. Worldly happiness was placed before religious salvation. Nothing was attacked with more intensity and ferocity than the church, with all its wealth, political power, and suppression of the free exercise of reason.
More than a set of fixed ideas, the Enlightenment implied an attitude, a method of thought. According to the German philosopher Immanuel Kant, the motto of the age should be “Dare to know.” A desire arose to reexamine and question all received ideas and values, to explore new ideas in many different directions—hence the inconsistencies and contradictions that often appear in the writings of 18th-century thinkers. Many proponents of the Enlightenment were not philosophers in the commonly accepted sense of the word; they were populizers engaged in a self-conscious effort to win converts. They liked to refer to themselves as the “party of humanity,” and in an attempt to mold public opinion in their favor, they made full use of pamphlets, anonymous tracts, and the large numbers of new journals and newspapers being created. Because they were journalists and propagandists as much as true philosophers, historians often refer to them by the French word philosophes.
In many respects, the homeland of the philosophes was France. It was there that the political philosopher and jurist Charles de Montesquieu, one of the earliest representatives of the movement, had begun publishing various satirical works against existing institutions, as well as his monumental study of political institutions, The Spirit of Laws (1748; trans. 1750). It was in Paris that Denis Diderot, the author of numerous philosophical tracts, began the publication of the Encyclopédie (1751-1772). This work, on which numerous philosophes collaborated, was intended both as a compendium of all knowledge and as a polemical weapon, presenting the positions of the Enlightenment and attacking its opponents. The single most influential and representative of the French writers was undoubtedly Voltaire. Beginning his career as a playwright and poet, he is best known today for his prolific pamphlets, essays, satires, and short novels, in which he popularized the science and philosophy of his age, and for his immense correspondence with writers and monarchs throughout Europe. Far more original were the works of Jean Jacques Rousseau, whose Social Contract (1762; trans. 1797), Émile (1762; trans. 1763), and Confessions (1782; trans. 1783) were to have a profound influence on later political and educational theory and were to serve as an impulse to 19th-century romanticism. The Enlightenment was also a profoundly cosmopolitan and antinationalistic movement with representatives in numerous other countries. Kant in Germany, David Hume in England, Cesare Beccaria in Italy, and Benjamin Franklin and Thomas Jefferson in the American colonies all maintained close contacts with the French philosophes but were important contributors to the movement in their own right.
During the first half of the 18th century, the leaders of the Enlightenment waged an uphill struggle against considerable odds. Several were imprisoned for their writings, and most were hampered by government censorship and attacks by the church. In many respects, however, the later decades of the century marked a triumph of the movement in Europe and America. By the 1770s, second-generation philosophes were receiving government pensions and taking control of established intellectual academies. The enormous increase in the publication of newspapers and books ensured a wide diffusion of their ideas. Scientific experiments and philosophical writing became fashionable among wide groups in society, including members of the nobility and the clergy. A number of European monarchs also adopted certain of the ideas or at least the vocabulary of the Enlightenment. Voltaire and other philosophes, who relished the concept of a philosopher-king enlightening the people from above, eagerly welcomed the emergence of the so-called enlightened despots, of whom Frederick II of Prussia, Catherine II of Russia, and Joseph II of Austria were the most celebrated examples. In retrospect, however, it appears that most of these monarchs used the movement in large part for propaganda purposes and were far more despotic than enlightened.
During the later 18th century certain changes in emphasis emerged in Enlightenment thought. Under the influence of Rousseau, sentiment and emotion became as respectable as reason. In the 1770s writers broadened their field of criticism to include political and economic issues. Of seminal importance in this regard was the experience of the American Revolution. In the eyes of Europeans, the Declaration of Independence and the Revolutionary War signaled that, for the first time, some individuals were going beyond the mere discussion of enlightened ideas and were actually putting them into practice. The American Revolution probably encouraged attacks and criticisms against existing European regimes.
The Age of Enlightenment is usually said to have ended with the French Revolution of 1789. Indeed, some see the social and political ferment of this period as being responsible for the Revolution. While embodying many of the ideals of the philosophes, the Revolution in its more violent stages (1792-94) served to discredit these ideals temporarily in the eyes of many European contemporaries. Yet the Enlightenment left a lasting heritage for the 19th and 20th centuries. It marked a key stage in the decline of the church and the growth of modern secularism. It served as the model for political and economic liberalism and for humanitarian reform throughout the 19th-century Western world. It was the watershed for the pervasive belief in the possibility and the necessity of progress that survived, if only in attenuated form, into the 20th century.