"Enlightenment is man's release from his self-incurred tutelage. Tuttelage is man's inability to make use of his understanding without direction from another. Self-incurred is this tutelage when its cause lies not in lack of reason but in lack of resolution and courage to use it without direction from another. Sapere aude! "Have courage to use your own reason!" that is the motto of Enlightenment.
Emanuel Kant 1783