No man so wise that he may not easily err if he takes no other counsel than his own. He that is taught only by himself has a fool for a master.
Source: In Correct Quotes for DOS, WordStar International, 1991.
-- Ben Jonson, (Jun 11 1572-1637), English poet, dramatist; He is regarded by many as second only to Shakespeare; his comedies include Every Man in His Humour.