age of reason

noun

1. any period in history, especially 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. (lowercase) the age at which a person is considered capable of distinguishing between right and wrong.

noun

1. the Age of Reason the 18th century in W EuropeSee also Enlightenment