"If human pleasure did not have both a lid and a time limit, we would not bestir ourselves to do things that were not pleasurable, such as toiling for our subsistence. And then we would not survive. By the same token, should our mass mind ever become discontented with the restricted pleasures doled out by nature, as well as disgruntled over the lack of restrictions on pain, we would omit the mandates of survival from our lives out of a stratospherically acerbic indignation. And then we would not reproduce. As a species, we do not shout into the sky, “The pleasures of this world are not enough for us.” In fact, they are just enough to drive us on like oxen pulling a cart full of our calves, which in their turn will put on the yoke. As inordinately evolved beings, though, we can postulate that it will not always be this way. “A time will come,” we say to ourselves, “when we will unmake this world in which we are battered between long burden and brief delight, and will live in pleasure for all our days.” The belief in the possibility of long-lasting, high-flown pleasures is a deceptive but adaptive flimflam. It seems that nature did not make us to feel too good for too long, which would be no good for the survival of the species, but only to feel good enough for long enough to keep us from complaining that we do not feel good all the time."