The first duty of a good inquisitor is to suspect especially those who seem sincere to him.

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

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

It was funny how I could feel all alone and under surveillance at the same time.

Once suspicion is aroused, everything feeds it.

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

I will never again command an army in America if we must carry along paid spies. I will banish myself to some foreign country first.

Nothing is hidden from the eyes of the observing world.

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

If you read somebody’s diary, you get what you deserve.

Even a paranoid can have enemies.

To know all is not to forgive all. It is to despise everybody.

There is nothing makes a man suspect much, more than to know little.