An Answer to the Question: What Is Enlightenment?

A short essay of 1784 in the Berlinische Monatsschrift, answering a question raised in a footnote in the same journal a year earlier. Kant defines enlightenment as humanity's emergence from its self-incurred immaturity, the inability to use one's own understanding without another's guidance. The immaturity is self-incurred when it comes from a lack of courage rather than of understanding, so the motto of enlightenment is Sapere aude: have courage to use your own understanding. People stay immature from laziness and fear, and because guardians find it easy to keep them so. A public can enlighten itself if left free, but only slowly; a revolution merely swaps old prejudices for new ones. Kant's key distinction is between the public use of reason, as a scholar addressing the reading world, which must always be free, and the private use of reason in an office or post, which may be restricted. We live, he says, not in an enlightened age but in an age of enlightenment, under Frederick the Great.

In a few pages it gives the classic definition of enlightenment and a lasting argument for freedom of public debate, and it is the easiest way to start reading Kant.