History warns us ... that it is the customary fate of new truths to begin as heresies and to end as superstitions.

The man of science has learned to believe in justification, not by faith, but by verification.

The scientific spirit is of more value than its products, and irrationally held truths may be more harmful than reasoned errors.

There is a light in every soul.

What would life be without challenges?

You always need to work hard. You always need to be willing to work hard. Not everything will be hard, but you should, at the very least, be willing to work hard.

If I ask you to think about something, you can decide not to. But if I make you feel something? Now I have your attention.

Where there is shouting, there is no true knowledge.

The funny thing about me that most people never really understand is that, at heart, I'm really a jock.

What is known for certain is dull.

Watching something is nothing like doing it.

True motivation is not getting people to play to their potential. It's getting people to play beyond their potential