Nothing is so difficult as not deceiving oneself.

It is possible--indeed possible even according to the old conception of logic--to give in advance a description of all 'true' logical propositions. Hence there can never be surprises in logic.

The world is the totality of facts, not of things

Where two principles really do meet which cannot be reconciled with one another, then each man declares the other a fool and a heretic

Everything that can be thought at all can be thought clearly. Everything that can be said can be said clearly. Ludwig Wittgenstein

A man will be imprisoned in a room with a door that's unlocked and opens inwards; as long as it does not occur to him to pull rather than push it.

You can't hear God speak to someone else, you can hear him only when you are being addressed.