And in man is a three-pound brain which, as far as we know, is the most complex and orderly arrangement of matter in the universe.

Robots will neither be common nor very good in 2014, but they will be in existence.

Congratulations on the new library, because it isn't just a library. It is a space ship that will take you to the farthest reaches of the Universe, a time machine that will take you to the far past and the far future, a teacher that knows more than any human being, a friend that will amuse you and console you-and most of all, a gateway, to a better and happier and more useful life.

No one can possibly have lived through the Great Depression without being scarred by it. No amount of experience since the depression can convince someone who has lived through it that the world is safe economically.

When I feel difficulty coming on, I switch to another book I'm writing. When I get back to the problem, my unconscious has solved it.

The law of conservation of energy tells us we can't get something for nothing, but we refuse to believe it.

During the century after Newton, it was still possible for a man of unusual attainments to master all fields of scientific knowledge. But by 1800, this had become entirely impracticable.