[To think for oneself] is the maxim of a reason never passive. The tendency to such passivity, and therefore to heteronomy of reason, is called prejudice; and the greatest prejudice of all is to represent nature as not subject to the rules that the understanding places at its basis by means of its own essential law, i.e. is superstition. Deliverance from superstition is called enlightenment; because although this name belongs to deliverance from prejudices in general, yet superstition especially (in sensu eminenti) deserves to be called a prejudice. For the blindness in which superstition places us, which it even imposes on us as an obligation, makes the need of being guided by others, and the consequent passive state of our reason, peculiarly noticeable.
Immanuel Kant, Critique of Judgment
enlightenment