What is enlightenment?

"The Enlightenment is one of the most important and contested periods in the history of philosophy. The problems it addressed, such as the proper extent of individual freedom and the challenging of tradition, resonate as much today as when they were first debated. Of all philosophers, it is arguably Kant who took such questions most seriously, addressing them above all in his celebrated short essay, An Answer to the Question: What is Enlightenment?