Men can imagine their own deaths, they can see them coming, and the mere though of impending death acts like an aphrodisiac. A dog or rabbit doesn't behave like that. Take birds -- in a lean season they cut down on the eggs, or they won't mate at all. They put their energy into staying alive themselves until times get better. But human beings hope they can stick their souls into someone else, some new version of themselves, and live on forever. As a species were doomed by hope, then? You could call it hope. That, or desperation. But we're doomed without hope, as well, said Jimmy. Only as individuals, said Crake cheerfully.