The realisation that our small planet is only one of many worlds gives mankind the perspective it needs to realise sooner that our own world belongs to all its creatures.

The best measure of a man's honesty isn't his income tax return. It's the zero adjust on his bathroom scale.

It is a good principle in science not to believe any 'fact'---however well attested---until it fits into some accepted frame of reference. Occasionally, of course, an observation can shatter the frame and force the construction of a new one, but that is extremely rare. Galileos and Einsteins seldom appear more than once per century, which is just as well for the equanimity of mankind.

I'm surprised at some technological development, and the realization that any sufficiently advanced technology is indistinguishable from magic. I think the CD-ROM is the best example of that. The idea of having a whole symphony, or opera, or novel in a little piece of plastic is pretty amazing.

Any sufficiently advanced technology is indistinguishable from magic.

The dinosaurs disappeared because they could not adapt to their changing environment. We shall disappear if we cannot adapt to an environment that now contains spaceships, computers - and thermonuclear weapons.

Our lifetime may be the last that will be lived out in a technological society.