the (currently) esoteric domain of self-reproducing machines—to the power and versatility of neurons and their synapses. This could become a new, great frontier of research. Here too, biology might point the way, as we come to understand biological development well enough to imitate its essence. Altogether, the advantages of artificial over natural intelligence appear permanent, while the advantages of natural over artificial intelligence, though substantial at present, appear transient. I’d guess that it will be many decades before engineering catches up, but—barring catastrophic wars, climate change, or plagues, so that technological progress stays vigorous—few centuries. If that’s right, we can look forward to several generations during which humans, empowered and augmented by smart devices, coexist with increasingly capable autonomous Als. There will be a complex, rapidly changing ecology of intelligence, and rapid evolution in consequence. Given the intrinsic advantages that engineered devices will eventually offer, the vanguard of that evolution will be cyborgs and superminds, rather than lightly adorned Homo sapiens. Another important impetus will come from the exploration of hostile environments, both on Earth (e.g., the deep ocean) and, especially, in space. The human body is poorly adapted to conditions outside a narrow band of temperatures, pressures, and atmospheric composition. It needs a wide variety of specific, complex nutrients, and plenty of water. Also, it is not radiation-hardened. As the manned space program has amply demonstrated, it is difficult and expensive to maintain humans outside their terrestrial comfort zone. Cyborgs or autonomous AIs could be much more effective in these explorations. Quantum Als, with their sensitivity to noise, might even be happier in the cold and dark of deep space. In a moving passage from his 1935 novel Odd John, science fiction’s singular genius Olaf Stapledon has his hero, a superhuman (mutant) intelligenc