Is that the Zeroth Law?
Yes. In the novel, Daneel and another robot (a less advanced overall but telepathic prototype named Giskard) find out about a plot to make the Earth uninhabitably radioactive. Giskard, being telepathic, can tell that the pro Earth faction is starting to stagnate, and starts to think that it might be better for more humans in the long term if the plot succeeds because it will force humans to renew efforts to expand into the stars. But that runs very counter to his First Law programming, so he can’t articulate this until the very end of the book. He explains this to Daneel, who (being more humanlike in external design but also in thought) is able to understand and internalize this. They decide to allow the Earth to become radioactive, and Daneel is capable of rationalizing this as being for the greater good of more humans over time, thus forming the Zeroth Law; the less advanced Giskard basically has his brain fried by the (in)action.
Actually, I didn’t remember this, but a wiki says that Giskard’s head was preserved by Daneel and accessed in the Foundation time period. I completely forgot about this, but it echoes what we saw on the show!
For robots advanced enough to fully internalize the Zeroth Law (in the novels I think that’s just Daneel but then it’s never explained what happened to the robots or why society distrusts anything robotlike so much, IIRC) killing an individual in accordance with the Zeroth Law is as easy as ignoring instructions or a robot’s own safety in order to obey the First Law and protect human life.
Maybe I’m misremembering (it has been many many years since I read the books and I was a teenager who only recently learned English at the time) but isn’t it almost implied that psychohistory doesn’t really work without the Second Foundation of telepathic spies moving pieces behind the scenes?
It’s been a long time since I read the books (40+ years) but I believe the telepathic spies were essential to Second Foundation.
The Second Foundation’s entire methodology was based on mental sciences rather than physical ones. Without telepathic spies positioned throughout the galaxy, they would have had no way to monitor Seldon’s plan and detect threats. It was their operational model.
Basically correct, though “telepathic spies moving pieces behind the scenes” may be overstating things a bit. The Second Foundation’s role is to adapt and perfect the Plan over time (as the First Speaker explains to his protégé), and to nudge it back on track in case of catastrophic events such as the Mule. But in order for the Plan to function properly, the First Foundation must be unaware of the Second’s existence; once the FF is aware, it must be convinced that the SF is no longer a factor. And the easiest way to do that is to convince the FF that the SF has been wiped out.
(Ninja’d by @Whack-a-Mole. Curses!)
You provided a lot more detail so better than my post.