What is the main idea of the Enlightenment?

The Enlightenment was an intellectual and philosophical movement which originated in Europe in the 1700s. This was a very complex movement in which many different ideas came to the fore but, in my opinion, it was the questioning of traditional forms of authority which is the most important. 

Prior to the Enlightenment, many countries in Europe had absolute monarchs who ruled the nation with complete power. But the philosophical ideals of the Enlightenment completely changed...

The Enlightenment was an intellectual and philosophical movement which originated in Europe in the 1700s. This was a very complex movement in which many different ideas came to the fore but, in my opinion, it was the questioning of traditional forms of authority which is the most important. 

Prior to the Enlightenment, many countries in Europe had absolute monarchs who ruled the nation with complete power. But the philosophical ideals of the Enlightenment completely changed this. In 1690, for example, John Locke published his Two Treatise of Government in which he argued that political authority was not divinely ordained and, in fact, grew out of a social contract between the governor and the governed. This was a very well-received and influential book.

The best example of this idea in practice is the French Revolution (1789-1799) in which France abolished its monarchy and, over a period of time, became a democratic republic, founded on the principles of democracy.