A sin is something which is not necessary.

In properly organized groups no faith is required; what is required is simply a little trust and even that only for a little while, for the sooner a man begins to verify all he hears the better it is for him.

If you want to lose your faith, make friends with a priest.

A man is never the same for long. He is continually changing. He seldom remains the same even for half an hour.

A man will renounce any pleasures you like but he will not give up his suffering.

A man can only attain knowledge with the help of those who possess it. This must be understood from the very beginning. One must learn from him who knows.