I believe, Messieurs, in loyalty---to one's friends and one's family and one's caste.

You can only really get under anybody's skin if you are married to them.

Never tell all you know—not even to the person you know best.

Our weapon is our knowledge. But remember, it may be a knowledge we may not know that we possess.

I have often had occasion to notice how, where a direct question would fail to elicit a response, a false assumption brings instant information in the form of a contradiction.

It is curious - but you cannot make a revolution without honest men. ... Every revolution has had its honest men. They are soon disposed of afterwards.

Many homicidal lunatics are very quiet, unassuming people. Delightful fellows.