In December 1784, Immanuel Kant published his answer to the question “What is Enlightenment?” in the Berlinische Monatsschrift. It begins: Aufklärung ist der Ausgang des Menschen aus seiner selbstverschuldeten Unmündigkeit. “Enlightenment is man’s emergence from his self-incurred immaturity.” Kant defined immaturity as the inability to use one’s own understanding without guidance from another. The motto of the Enlightenment, he wrote, is Sapere aude! Have the courage to use your own understanding.