- enlightenment 1660s, "action of enlightening," from ENLIGHTEN (Cf. enlighten) + -MENT (Cf. -ment). Only ever used in figurative sense, of spiritual enlightenment, etc. Attested from 1865 as a translation of Ger. Aufklärung, a name for the spirit and system of Continental philosophers in the 18c.The philosophy of the Enlightenment insisted on man's essential autonomy: man is responsible to himself, to his own rational interests, to his self-development, and, by an inescapable extension, to the welfare of his fellow man. For the philosophes, man was not a sinner, at least not by nature; human nature -- and this argument was subversive, in fact revolutionary, in their day -- is by origin good, or at least neutral. Despite the undeniable power of man's antisocial passions, therefore, the individual may hope for improvement through his own efforts -- through education, participation in politics, activity in behalf of reform, but not through prayer. [Peter Gay, "The Enlightenment"]
Etymology dictionary. 2014.