Grip the nettle firmly and it will become a stick with which to beat your enemy. - Isaac Asimov

He had no credits to continue his work — no credits to locate others like Wanda, no credits to pay his workers on the Psychohistory Project at Streeling, no credits to set up his all-important Encyclopedia Project at the Galactic Library. Now what?

Men grew desperate and the border between bitter frustration and wild destruction is sometimes easily crossed.

We have: One, a robot may not injure a human being, or, through inaction, allow a human being to come to harm.