What was Enlightenment? Explaining the Age of Reason

The Enlightenment was an intellectual movement in Europe during the 17th and 18th centuries that celebrated reason and knowledge. It marked a progression in what humans believed about themselves and the universe. Enlightenment thinkers and philosophers shared exciting ideas across subjects like art, culture, politics, religion, and science. This new exploration of knowledge felt like freedom, and that marked the era with a sense of optimism and happiness. It wasn’t the first time more rational ideas had made their way to the public. In the late Middle Ages renewed interest in Greek philosophers like Aristotle encouraged scholars to reason their way to truth. In time, all that classical reading gave rise to Renaissance humanism, which in turn inspired 16th-century scientists to ask big questions like: “Does the Earth revolve around the Sun?” and “What’s the best way to test your theory or observation?” This set the stage for the Enlightenment, an era when French thought leaders like Voltaire, Rousseau, and Diderot introduced new ideas about social progress, free will, and memory. Encyclopaedias published in this era offered a way to document and categorize humanity’s growing knowledge. Arguably the most impactful one was first printed in Scotland in 1768…maybe you’ve heard of it? Toward the end of the 1700s, the excitement surrounding the Enlightenment began to dwindle. The emphasis on intellectualism prompted contrarians to explore the depth of human emotion. This led to the cultural movement known as Romanticism, which celebrated imagination and creativity rather than reason. The Enlightenment inspired many of the leaders of the American Revolution, including Benjamin Franklin and Thomas Jefferson. The big tenets of Enlightenment—religious tolerance, rational thought, and the emphasis on science—can be seen right in the Declaration of Independence. This new way of thinking about government, freedom, and citizenship helped inspire the founding of the United States. The ideas of the Enlightenment were powerful—so powerful that they ultimately brought about the era’s demise. But the discoveries, philosophies, and intellectual freedom of the period never died out. The search for knowledge never ends. That’s what brought you here to Britannica, after all!