No one demands more caution than a spy, and when someone has the skeleton key to minds, counter him by leaving the key of caution inside, on the other side of the keyhole.

Hear, see, and be silent.

Evil report carries further than any applause.

Know or listen to those who know.

If you are wise, live as you can; if you cannot, live as you would.

Admiration is the basis of ignorance.

Don't lie, but don't tell the whole truth.