Enlightenment is man's emergence from his self-imposed immaturity. Immaturity is the inability to use one's understanding without guidance from another. This immaturity is self-imposed when its cause lies not in lack of understanding, but in lack of resolve and courage to use it without guidance from another. Sapere Aude! [Dare to know!] "Have courage to use your own understanding!"--that is the motto of enlightenment.

Laziness and cowardice are the reasons why so great a proportion of men, long after nature has released them from alien guidance, nonetheless gladly remain in lifelong immaturity, and why it is so easy for others to establish themselves as their guardians. It is so easy to be immature. If I have a book to serve as my understanding, a pastor to serve as my conscience, a physician to determine my diet for me, and so on, I need not exert myself at all. I need not think, if only I can pay: others will readily undertake the irksome work for me. […]

Nothing is required for this enlightenment, however, except freedom; and the freedom in question is the least harmful of all, namely, the freedom to use reason publicly in all matters. But on all sides I hear: "Do not argue!" The officer says, "Do not argue, drill!" The tax man says, "Do not argue, pay!" The pastor says, "Do not argue, believe!" […]

If it is now asked, "Do we presently live in an enlightened age?" the answer is, "No, but we do live in an age of enlightenment." [...]

I. Kant Koenigsberg in Prussia, 30 September 1784