My objection to organized religion is the premature conclusion to ultimate truth that it represents.

If there are any gods whose chief concern is man, they can't be very important gods.

Human judges can show mercy. But against the laws of nature, there is no appeal.

I'm sometimes asked how I would like to be remembered. I've had a diverse career as a writer, underwater explorer, space promoter and science populariser. Of all these, I want to be remembered most as a writer - one who entertained readers, and, hopefully, stretched their imagination as well.

I don't believe in astrology; I'm a Sagittarius and we're skeptical.

When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong. Perhaps the adjective 'elderly' requires definition. In physics, mathematics, and astronautics it means over thirty; in the other disciplines, senile decay is sometimes postponed to the forties. There are, of course, glorious exceptions; but as every researcher just out of college knows, scientists of over fifty are good for nothing but board meetings, and should at all costs be kept out of the laboratory!

In all the universe there is nothing more precious than mind.