The inspirational value of the space program is probably of far greater importance to education than any input of dollars... A whole generation is growing up which has been attracted to the hard disciplines of science and engineering by the romance of space.

A precondition for being a science fiction writer other than an interest in the future is that, an interest - at least an understanding of science, not necessarily a science degree but you must have a feeling for the science and its possibilities and its impossibilities, otherwise you're writing fantasy. Now, fantasy is also fine, but there is a distinction, although no one's ever been able to say just where the dividing lines come.

I believe any malevolent supercivilisation would have rapidly self-destructed as we may be in the process of doing ourselves. If we do have contact, physical contact with aliens, I think it will be benign.

I am an optimist. Anyone interested in the future has to be otherwise he would simply shoot himself.

The only way to define your limits is by going beyond them.

One of the great tragedies of mankind is that morality has been hijacked by religion. So now people assume that religion and morality have a necessary connection. But the basis of morality is really very simple and doesn't require religion at all.

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