It has yet to be proven that intelligence has any survival value.

They had not yet attained the stupefying boredom of omnipotence; their experiments did not always succeed.

When I start on a book, I have been thinking about it and making occasional notes for some time... So I have lots of theme, locale, subjects and technical ideas... I don't worry about long periods of not doing anything. I know my subconscious is busy.

A hundred years ago, the electric telegraph made possible-indeed, inevitable-the United States of America. The communications satellite will make equally inevitable a United Nations of Earth; let us hope that the transition period will not be equally bloody.

The time was fast approaching when Earth, like all mothers, must say farewell to her children.

Don't mess up the environment until you're quite sure what you're doing.

Science fiction seldom attempts to predict the future. More often than not, it tries to prevent the future.