The difference between machines and human beings is that human beings can be reproduced by unskilled labour.

I have encountered a few "creationists" and because they were usually nice, intelligent people, I have been unable to decide whether they were really mad or only pretending to be mad. If I was a religious person, I would consider creationism nothing less than blasphemy. Do its adherents imagine that God is a cosmic hoaxer who has created the whole vast fossil record for the sole purpose of misleading humankind?

Training was one thing, reality another.

When one has to ask, "Am I really in love?" the answer is always "No".

I also believe - and hope - that politics and economics will cease to be as important in the future as they have been in the past; the time will come when most of our present controversies on these matters will seem as trivial, or as meaningless, as the theological debates in which the keenest minds of the Middle Ages dissipated their energies. Politics and economics are concerned with power and wealth, neither of which should be the primary, still less the exclusive, concern of full-grown men.

The moon is the first milestone on the road to the stars.

Only small minds are impressed by large numbers.