On my last night in Montana, I gave a talk on transhumanism to a right-wing organization. This was the third meeting I’d attended, held in the basement of an old Eagles Lodge. It really was a great honor. There were about forty people in the audience, I’d say, and about twenty holstered pistols. You don’t say the wrong thing to a crowd like that. Any more, I open my talks on transhumanism by noting that what we’re talking about is mostly fantasy. Genetic engineering on demand, sentient artificial superintelligence, commercial brain-computer interfaces—these are all disturbing ideas that exist, by and...