Tiger got to hunt, Bird got to fly; Man got to sit and wonder, “Why, why, why?” Tiger got to sleep, Bird got to land; Man got to tell himself he understand.

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.