Two possibilities exist: Either we are alone in the Universe or we are not. Both are equally terrifying.

Death focuses the mind on the things that really matter: why are we here, and what should we do?

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.

In this single galaxy of ours there are eighty-seven thousand million suns. [...] In challenging it, you would be like ants attempting to label and classify all the grains of sand in all the deserts of the world. [...] It is a bitter thought, but you must face it. The planets you may one day possess. But the stars are not for man.

The entire sweep of human history from the dark ages into the unknown future was considerably less important at the moment than the question of a certain girl and her feelings toward him.

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.

It is vital to remember that information - in the sense of raw data - is not knowledge, that knowledge is not wisdom, and that wisdom is not foresight. But information is the first essential step to all of these.