In order to be able to set a limit to thought, we should have to find both sides of the limit thinkable (i.e. we should have to be able to think what cannot be thought).

Nothing is so difficult as not deceiving oneself.

Logic is not a body of doctrine, but a mirror-image of the world. Logic is transcendental.

What Copernicus really achieved was not the discovery of a true theory but of a fertile new point of view.

In order to be able to set a limit to thought, we should have to find both sides of the limit thinkable (i.e. we should have to be able to think what cannot be thought).

That which cannot be said must not be said. That which cannot be said, one must be silent thereof.

A logical picture of facts is a thought.