The Age of Enlightenment or the Enlightenment , also known the Age of Reason, was an intellectual and philosophical movement that occurred in Europe in the 17th and 18th centuries global influences and effects. The Enlightenment included a range of ideas centered on the value of human happiness, the pursuit of knowledge obtained by means of reason and the evidence of the senses, and ideals such as natural law, liberty, progress, toleration, fraternity, constitutional government, and separation of church and state.

The Enlightenment was preceded by the Scientific Revolution and the work of Francis Bacon, John Locke, among others. Some date the beginning of the Enlightenment to the publication of René Descartes' Discourse on the Method in 1637, featuring his famous dictum, Cogito, ergo sum ("I think, therefore I am"). Others cite the publication of Isaac Newton's Principia Mathematica (1687) as the culmination of the Scientific Revolution and the beginning of the Enlightenment. European historians traditionally date its beginning with the death of Louis XIV of France in 1715 and its end with the 1789 outbreak of the French Revolution. Many historians now date the end of the Enlightenment as the start of the 19th century, with the latest proposed year being the death of Immanuel Kant in 1804.

Philosophers and scientists of the period widely circulated their ideas through meetings at scientific academies, Masonic lodges, literary salons, coffeehouses and in printed books, journals, and pamphlets. The ideas of the Enlightenment undermined the authority of the monarchy and the Catholic Church and paved the way for the political revolutions of the 18th and 19th centuries. A variety of 19th century movements including liberalism, communism, and neoclassicism trace their intellectual heritage to the Enlightenment.

The central doctrines of the Enlightenment were individual liberty and religious tolerance, in opposition to an absolute monarchy and the fixed dogmas of the Church. The concepts of utility and sociability were also crucial in the dissemination of information that would better society as a whole. The Enlightenment was marked by an increasing awareness of the relationship between the mind and the everyday media of the world, and by an emphasis on the scientific method and reductionism, along with increased questioning of religious orthodoxy—an attitude captured by Kant's essay Answering the Question: What is Enlightenment, where the phrase Sapere aude (Dare to know) can be found.