Doubt is a necessity of the mind, faith of the heart.
We often make people pay dearly for what we think we give them.
You should only confide your secrets to someone who has not tried to guess them.
The best way to find out if a man has done something is to advise him to do it. He will not be able to resist boasting that he has done it without being advised.
Prejudices are the refuge of those who cannot think for themselves.