The Age of Enlightenment was an 18th century movement that started in Paris and spread across Europe to the American colonies. It was shaped by scientists like Bacon and Newton, advancing the application of natural laws to the understanding of all phenomena. John Locke’s Essay Concerning Human Understanding was an essential work arguing, against Descartes, that all knowledge is derived from experience. It mapped the foundations for scientific psychology. The novel emerged in philosophy and literature, including writers like Daniel Defoe and Jean-Jacques Rousseau. Voltaire advocated for civil liberties and was influential in the American and French revolutions.
These thinkers and many more are surveyed in a fun little book called, Introducing the Enlightenment: A Graphic Guide by Lloyd Spencer and Andrzej Krauze. I often enjoy these short guides, either as an introduction to a subject or a review of it. You can get the same information from Wikipedia, but not the clever graphics. I was previously well-served by a book with a similar format, Introducing Critical Theory by Stuart Sim.
The Enlightenment was an important movement. It introduced the first encyclopedia, the collection of many branches of knowledge into a single place. It advanced scientific knowledge and the arts, atheism and religious movements, economics and industrialism. Secular and intellectual, it was the foundation of modern Western philosophy. It can be credited or blamed with the advance of technologies that characterize modern life. Some say that this movement concluded in tragedy with our two world wars. Many still struggle to invent new disciplines and technologies, hoping they will yet save us from the increasing complexity of life.
There is a second sense of the term, enlightenment. The Age of Enlightenment was known for its application of reason and analysis. The second sense is not rational in the same way, but refers to a complete apprehension or gestalt experience that transforms a person or situation. Call it spiritual enlightenment. Note though that the rise and decline of Christianity maps better to the Age of Enlightenment. Spiritual enlightenment is associated with Eastern philosophy.