The Enlightenment, also known as the Age of Reason or Aufklärung, is a term applied to the period of European intellectual history centered on the mid-eighteenth century. The empiricist philosophy of John Locke and scientific optimism following Isaac Newton's Principia provided the confidence to deem reason supreme in all departments of intellectual enquiry.

 

After the Renaissance, when ancient Greco-Roman ideas were rediscovered in the West, came the Enlightenment (broadly, the 17th and 18th centuries). It was the age in which men began to doubt authority and to observe the world for themselves. The scientific revolution of the 17th century was an important influence on the philosophers of the Enlightenment. During the 18th century there was a common Anglo-French civilization, dominated by the influence of Newton and Locke. Typical of this civilization was the Encyclopédie (1751–1765), edited by Denis Diderot and Jean d'Alembert, which brought together up-to-date knowledge and dealt with political, social, scientific, and educational ideas.

 

The German Aufklärung (enlightenment) of the late 18th century belongs to the same movement. In social affairs, as distinct from ideas, it was the French Revolution (1789) that swept away the remains of the medieval system. Enlightenment thinkers were much concerned with "reason" (roughly "active intelligence") and "nature" ("the state of things as they are"). By exercising reason, men were able to make nature human (as in the art of the landscape architect) and society natural (on the basis of "natural rights"). They mistrusted enthusiasm and imagination, remembering the barbarous wars of religion. They redirected their energies toward science and the reshaping of society. These thinkers believed that by making men see reason through argument, society would be changed and human behavior improved. In this they were certainly over-optimistic; nevertheless the Enlightenment tradition had a powerful influence on the social development of the 19th century.