I have yet to see any problem, however complicated, which, when you looked at it in the right way, did not become still more complicated..

At each stage...entirely new laws, concepts and generalizations are necessary, requiring inspiration and creativity to just as great a degree as in t….

Better a life like a falling star, brief bright across the dark, than the long, long waiting of the immortals, loveless and cheerlessly wise..

Let us settle down to the serious business of getting drunk..

The fish that first ventured ashore had considerable practical problems..

There are some ideas so stupid that only intellectuals can believe in them, particularly left-wing intellectuals..

In Harvest of Stars, there is this notion, not original with me of course, that it will become possible to download at least the basic aspects of a h….

Timidity can be as dangerous as rashness..

Colonization means potential immortality for the human genus. Man's safety on Earth was never great, and it dwindles hourly. Disarmament, even world ….

Give fear no hold on you. Keep sinews loose and senses open, ready at every instant to flow with the rush of action..

If we knew exactly what to expect throughout the Solar System, we would have no reason to explore it..

A fanatic's willingness to kill or be killed in the service of a cause cannot prove the rightness of that cause..

A fanatic is a man who, when he's lost sight of his purpose, redoubles his effort..

A man isn't really alive till he has something bigger than himself and his own little happiness, for which he'd gladly die..

Machines can only find what ignorant men have programmed them to find..

The single definition of government I've ever seen that makes sense is that it's the organization which claims the right to kill people who won't do ….

Heaven is not as narrowly literal-minded as hell..

What five books would I like to be remembered for? Well... Tau Zero, I like that one especially. It was somewhat of a tour de force, and I think it g….

I wrote the first book, Harvest of Stars, and as I was writing it, I saw that certain implications had barely been touched on... It's perfectly obvio….

My knowledge of the human psyche is as yet imperfect. Certain areas won't yield to computation..

Two lives met across death and centuries. To ask what it meant is meaningless. There is no destiny. But sometimes there is bravery.