When we can't think for ourselves, we can always quote

We could present spatially an atomic fact which contradicted the laws of physics, but not one which contradicted the laws of geometry.

Don't get involved in partial problems, but always take flight to where there is a free view over the whole single great problem, even if this view is still not a clear one.

Genius is what makes us forget the master's talent.

At the core of all well-founded belief lies belief that is unfounded.

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.