Will it destroy us, or will it save us? An age-old debate between tech optimists and tech pessimists that has played out over centuries as the steady march of human progress delivers new technologies, from the wheel to the printing press to the smartphone. Today it is a conversation being conducted with increasing urgency about artificial intelligence. The optimists point out that history has proved the doomsayers wrong countless times. Take the printing press: the 15th-century Catholic church worried that the spread of information would undermine authority and stability across Europe; some intellectuals worried that information would be dangerous in...