You ask me if I keep a notebook to record my great ideas. I've only ever had one.

If I had only one hour to save the world, I would spend fifty-five minutes defining the problem, and only five minutes finding the solution.

I do not believe in the God of theology who rewards good and punishes evil.

It would of course be a great step forward if we succeeded in combining the gravitational field and the electromagnetic field into a single structure. Only so could the era in theoretical physics inaugurated by Faraday and James Clerk Maxwell be brought to a satisfactory close.

The world is in greater peril from those who tolerate or encourage evil than from those who actually commit it.

No worthy problem is ever solved within the plane of its original conception.

The most fundamental question we can ever ask ourselves is whether or not the universe we live in is friendly or hostile.