A robot must protect its own existence as long as such protection does not conflict with the First or Second Laws.

Rejection slips, or form letters, however tactfully phrased, are lacerations of the soul, if not quite inventions of the devil-but there is no way around them.

It is the chief characteristic of the religion of science that it works.

Violence is the last refuge of the incompetent.

To all my gentle readers who have treated me with love for over 30 years, I must say farewell. It has always been my ambition to die in harness with my head face down on a keyboard and my nose caught between two of the keys, but that's not the way it worked out. I have had a long and happy life and I have no complaints about the ending, thereof, and so farewell - farewell.

Feminine intuition? Is that what you wanted the robot for? You men. Faced with a woman reaching a correct conclusion and unable to accept the fact that she is your equal or superior in intelligence, you invent something called feminine intuition.

The fall of Empire, gentlemen, is a massive thing, however, and not easily fought. It is dictated by a rising bureaucracy, a receding initiative, a freezing of caste, a damming of curiosity — a hundred other factors. It has been going on, as I have said, for centuries, and it is too majestic and massive a movement to stop.