... you just can't differentiate between a robot and the very best of humans.

Arthur Clarke says that I am first in science and second in science fiction in accordance with an agreement we have made. I say he is first in science fiction and second in science.

No sensible decision can be made any longer without taking into account not only the world as it is, but the world as it will be.

There never can be a man so lost as one who is lost in the vast and intricate corridors of his own lonely mind, where none may reach and none may save.

There is an art to science, and a science in art; the two are not enemies, but different aspects of the whole.

Uncertainty that comes from knowledge (knowing what you don't know) is different from uncertainty coming from ignorance.

Despite all that education and experience can do, I retain a certain level of unsophistication that I cannot eradicate and that my friends find amusing. In fact, I think I sometimes detect conspiratorial plottings among my friends to protect me against my own lack of sophistication. I don't mind. I suspect that I am never quite as unsophisticated as they think I am, but I don't mind.