Something along the lines of: A cat may not injure a human being or, through inaction, allow a human being to come to harm.

A robot may not injure a human being or, by failing to act, allow a human being to come to harm.

The First Law states that a robot cannot injure a human being or, through inaction, allow a human being to come to harm.

And there could only be one reason for the battle he had just witnessed: Lucius had injured a human being.

I may not injure a human being,?

It just never occurs to me to say injure a human being.

A robot may not injure a human being.

The first part, "A robot may not injure a human being," is absolute and nothing need be done about that.

And we're all like, 'not able to injure a human being or let them come to harm'.

A robot may not injure a human being or, through inaction, allow a human being to come to harm.