So far as we know, animals do not live in constant anxiety about sickness and death, as we do, because they live in the present. Nevertheless, they will fight when in hunger or when attacked. We must, however, be careful of taking animals as models of “perfectly natural” behavior. If “natural” means “good” or “wise,” human beings can improve on animals, though they do not always do so. But human beings, especially in Western civilization, make death the great bogey. This has something to do with the popular Christian belief that death will be followed by the dread Last Judgment, when sinners will be consigned to the temporary horrors of Purgatory or the everlasting agony of Hell. More usual, today, is the fear that death will take us into everlasting nothingness—as if that could be some sort of experience, like being buried alive forever.