“You see,” Norman said, “at first I thought the Anthropomorphic Problem—the fact that we can only conceive of extraterrestrial life as basically human—I thought it was a failure of imagination. Man is man, all he knows is man, and all he can think of is what he knows. Yet, as you can see, that’s not true. We can think of plenty of other things. But we don’t. So there must be another reason why we only conceive of extraterrestrials as humans. And I think the answer is that we are, in reality, terribly frail animals. And we don’t like to be reminded of how frail we are—how delicate the balances are inside our own bodies, how short our stay on Earth, and how easily it is ended. So we imagine other life forms as being like us, so we don’t have to think of the real threat—the terrifying threat—they may represent, without ever intending to.”