One man's ways may be as good as another's, but we all like our own best.

When in doubt, don't.

Only crime and the criminal, it is true, confront us with the perplexity of radical evil; but only the hypocrite is really rotten to the core.

I'm not as famous as Stephen Hawking, but certainly in the U.S., I have a very high profile for a scientist. It is an awesome responsibility, one that I don't shoulder lightly.

If there is something to pardon in everything, there is also something to condemn.