It is always safe to learn, even from our enemies, seldom safe to venture to instruct, even our friends.

Imitation is the sincerest form of flattery.

Examinations are formidable even to the best prepared, for the greatest fool may ask more than the wisest man can answer.

When you have nothing to say, say nothing; a weak defense strengthens your opponent, and silence is less injurious than a bad reply.