Kant, Immanuel (Immanuel Kant)

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 the lack of understanding, but in the lack of resolve and courage to use it without guidance from another. Have courage to use your own understanding!
-- Immanuel Kant

Man is the only creature which must be educated.
-- Immanuel Kant