Preference of vice to virtue, a manifest wrong judgment. — John Locke

No man's knowledge here can go beyond his experience.

Since sounds have no natural connection with our ideas ... the doubtfulness and uncertainty of their signification ... has its cause more in the ideas they stand for than in any incapacity there is in one sound more than another to signify any idea.

It is one thing to show a man that he is in error, and another to put him in possession of the truth.