If you want a love message to be heard, it has got to be sent out. To keep a lamp burning, we have to keep putting oil in it.

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

When in doubt, don't.

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.

The point - the power to hurt - of all figures lies in the truthfulness of their application.