Proof Quote by Julia Child

Theory is good; but it doesn't prevent things from existing.

— Jean-Martin Charcot

Never worry about theory as long as the machinery does what it's supposed to do.

— Robert A. Heinlein

Action will remove the doubt that theory cannot solve

— Pehyl Hsieh

There can be theory but, you know, the problem is you've got to be able to test it. So theories are one thing, testing…

— Brian Schmidt

There is nothing so practical as a good theory.

— Kurt Lewin

Action will remove the doubts that theory cannot solve.

— Tehyi Hsieh

I believe that proving is not a natural activity for mathematicians.

— Rene Thom

Another thing I must point out is that you cannot prove a vague theory wrong.

— Richard P. Feynman

No theory is good unless it permits, not rest, but the greatest work. No theory is good except on condition that one use it…

— Andre Gide

There is another theory that states: This has already happened ....

— Douglas Adams

The very best proof that something can be done is that someone has already done it.

— Bertrand Russell

A good theory explains a lot but postulates little.

— Richard Dawkins