Musk’s alarming views on the dangers of A.I. first went viral after he spoke at M.I.T. in 2014—speculating (pre-Trump) that A.I. was probably humanity’s “biggest existential threat.” He added that he was increasingly inclined to think there should be some national or international regulatory oversight—anathema to Silicon Valley—“to make sure that we don’t do something very foolish.” He went on: “With artificial intelligence, we are summoning the demon. You know all those stories where there’s the guy with the pentagram and the holy water and he’s like, yeah, he’s sure he can control the demon? Doesn’t work out.”