Prelude to Foundation (Foundation, #6)

by Isaac Asimov

“Undesired knowledge is useless knowledge,” said Dors. “Can you imagine all the time, effort, and energy expended in a continual refurbishing of unused data? And that wastage would grow steadily more extreme with time.” “Surely, you would have to allow for the fact that someone at some time might need the data being so carelessly disposed of.” “A particular item might be wanted once in a thousand years. To save it all just in case of such a need isn’t cost-effective. Even in science.

the Three Laws of Robotics that are traditionally put into words—or once were, long ago. They are these: “ ‘One. A robot may not injure a human being or, through inaction, allow a human being to come to harm. “ ‘Two. A robot must obey the orders given it by human beings, except where such orders would conflict with the First Law. “ ‘Three. A robot must protect its own existence, as long as such protection does not conflict with the First or Second Law.’

the Zeroth Law, since zero comes before one. It is: “ ‘Zero. A robot may not injure humanity or, through inaction, allow humanity to come to harm.’ “Then the First Law must read: “ ‘One. A robot may not injure a human being or, through inaction, allow a human being to come to harm, except where that would conflict with the Zeroth Law.’ “And the other laws must be similarly modified.