Secrets are rarely betrayed or discovered according to any program our fear has sketched out.

Nothing is hidden from the eyes of the observing world.

Guard more faithfully the secret which is confided to you than the money which is entrusted to your care.

There is a sickness among tyrants: they cannot trust their friends.

Even a paranoid can have enemies.

For sooner will men hold fire in their mouths than keep a secret.

The life of spies is to know, not be known.

There is nothing more deceptive than an obvious fact.

Spies are of no use nowadays. Their profession is over. The newspapers do their work instead.