Enlightenment is a person’s emergence from his self-sustained dependency. “Dependency” is the inability to make use of one’s intellect without the supervision of another. One’s dependency is “self-sustained” when its cause lies not in defect of intellect but in lack of the decisiveness and courage to make use of one’s mind without the direction of another. Sapere aude! “Have the courage to make use of your own mind!” is thus the slogan of the Enlightenment.