In a collaboration, each author will do 75% of the work.

Ethics change with technology.

SF isn't a genre; SF is the matrix in which genres are embedded, and because the SF field is never going in any one direction at any one time, there is hardly a way to cut it off.

The human species really could have faced global thermonuclear war. During seventy years of Cold War we grew used to it.

Everything starts as somebody's daydream.

In the world of words the imagination is one of the forces of nature.

In hindsight it may even seem inevitable that a socialist society will starve when it runs out of capitalists.

You learn by writing short stories. Keep writing short stories. The money's in novels, but writing short stories keeps your writing lean and pointed.

We learn only to ask more questions.

It's very difficult for a black man to get out of South-Central Los Angeles, and get out civilized....The only men I know who have escaped, all began reading Robert Heinlein at age ten.

One mark of a good officer, he remembered, was the ability to make quick decisions. If they happen to be right, so much the better.

Under every friendship there is a difficult sentence that must be said, in order that the friendship can be survived.

These fragments I have shored against my ruins

I received my undergraduate degree in engineering in 1939 and a Master of Science degree in mathematical physics in 1941 at Steven Institute of Technology.

Science is what we know, and philosophy is what we don't know.

I enjoy the cleaning up - something about the getting of things in order for winter - making the garden secure - a battening down of hatches perhaps... It just feels right.

I grew up in the United States.

Trust life, even if you cannot trust people. For human nature is unreliable, but life itself is ruled by immutable law. Right action leads always, in the end, to victory.

On two legs, Mickey Mantle would have been the greatest ballplayer who ever lived.

Christianity is not devotion to work, or to a cause, or a doctrine, but devotion to a Person, the Lord Jesus Christ.

The universe is probably littered with one-planet graves