Age' of Rea'son
1. any period in history, esp. the 18th century in France, England, etc., characterized by a critical approach to religious, social, and philosophical matters that seeks to repudiate beliefs or systems not based on or justifiable by reason.
2. (l.c.) the age at which a person is considered capable of distinguishing between right and wrong.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.