I mean the title of this post to convey the idea that humans are never satisfied; each time one desire is quenched, another arises, so we are in a constant state of anticipation. My thoughts came in direct response to what I read in Schopenhauer, and, by projection, to the general Buddhist approach to psychology. I was surprised to find that a Google search on "human desire is never satisfied" actually brought back mainly Christian sites, chiefly in reference to Proverbs 27:20: "Hell and destruction are never full; so the eyes of man are never satisfied" (KJV). Not that it should be surprising that this subject is present in Christianity as in other religions and philosophies. In fact, the nature of human longing is central to any study of man. It is what I think of as the problem of motivation, which indicates that I approach it largely from the other direction: how to convince myself or someone else to do something, not how to deal with the fact that I always want things that I don't have. The subject of just about any human science seems to boil down to this, which Ludwig von Mises expressed in his masterpiece's title as "Human Action." His way of approaching motivation was to say that humans act to "remove unease," which I find as good a description as any, although probably incomplete.
In any case, everyone agrees that humans are never satisfied. In Buddhism in particular, desire is not only a problem but the central problem, because unfulfilled desire is the source of unhappiness. The unique solution in Buddhism is not to direct or limit desire, but to extinguish it altogether. Schopenhauer, who claims to have reached his philosophy independently (without prior knowledge of Buddhism), expounds at great length on the way that desire inherently means conflict. He also argues that desire never ends, because the satisfaction of one desire is always followed immediately by the arousal of another one. Moreover, if one great desire is quenched, we pay more attention to the lesser ones, so that they end up causing the same anxiety. It is a sort of law of conservation of desire (or, more accurately, of frustration).
It is this last part that I want to take issue with. It seems plausible enough, especially if we think of human action in Misian terms as the removal of unease: if we act at all, there must be some deficit in our satisfaction; and since we almost always act, we must be constantly unsatisfied. What I recently realized, though, is that this description of the problem is like Zeno's paradox. Zeno told the story of Achilles and the tortoise in a footrace. If Achilles gave the tortoise a head start, he could never catch up. You see, first he would have to make up half the distance between himself and the tortoise, and during that time the tortoise would have moved forward; then he would have to make up half the distance again, during which time the tortoise would have moved further ahead. You can repeat these steps infinitely, but Achilles will always have halfway to go, so he will never pass the tortoise.
We know intuitively that this is nonsense (even though, if I understand correctly, Zeno was actually trying to prove that motion is impossible), but why? Because we are slicing time into ever smaller amounts to leave Achilles behind. And while it might appear that this can continue indefinitely, we now know that infinitely dividing something eventually converges, so that time will continue to pass and Achilles will eventually catch up with and pass the tortoise.
The problem of desire is quite different, but it makes the same fundamental mistake about time. Let's say you eat breakfast at 8 a.m. At noon, you eat lunch again. Who is going to say, "Look at that guy! He just ate four hours ago, and now he's eating again!" That wouldn't make much sense, because we know that humans need to eat every few hours to have enough energy to keep going. The fact that you ate in the morning has pretty much no relevance to it; you are bound to be hungry again several hours later unless perhaps you stuffed yourself well beyond what you needed.
Have you ever had one of those moments where you felt completely at ease? Some time when everything seemed right: you didn't want anything, you had no outstanding anxieties, you just felt at peace. Chances are that a short time later -- five minutes or five hours or (if you were extremely lucky) five days -- you no longer had the same feeling. Does that mean that you created things to worry about? Well, it could. We all know that people who get rich often turn out very unhappy. They thought that money would solve all their problems, and they were wrong. But the error there was in thinking that everything was perfect, not that they had to create problems for themselves as a matter of human nature. The fact is, even after you get money, you still have to go on living. You may not have any monetary needs, but you still have other needs, such as someone to love and something to occupy your time. Money is notoriously bad at solving those problems. If you feel at peace for a while because all of your immediate problems are solved, that doesn't mean that you won't face new issues in the future. In particular, the intangible things related to our minds, such as finding and keeping friends, remain forever. They even become more difficult, in some respects, if you have money, although the difficulties are of a very different type than if you are poor. Still, I don't see how we can doubt that a person who has come into money may have had some great burdens lifted, and may feel quite at peace for a time. He may have his personal issues resolved for the time being, and his monetary issues resolved perhaps for the first time ever. If he thinks he will never suffer again, he is naive; but if he thinks that things are good at that moment, he is quite right and has ever reason to feel it with satisfaction. That does not mean that he may not get in a quarrel with his spouse later that day and be miserable, but neither does the quarrel mean that his previous peace was not real. It was, but he has to go on living, has to go on fulfilling his psychological needs just as his physical needs. It makes no more sense to criticize a person for having ongoing psychological needs than for getting hungry every few hours.
This is not the same sort of problem as Zeno's paradox, but I think it has a similar nature. Zeno ignored time, or thought that he could divide it infinitely without approaching a limit of zero when there was no more time to be divided. People who think that human desire is never fulfilled are correct to the extent that we all have desires that rekindle from one moment to the next. But the key point is those passing moments. At a particular moment, your desires might be fulfilled (or, alternately, you may have achieved peace of mind sufficiently that you are content even if there is more you could wish for -- that is another whole dimension to the problem). What you cannot prevent is that, in living on, your desires will present themselves anew at ever moment. This is why I have always had trouble with Solon's pronouncement that he only judges a man happy when his life is over, as though how a man dies determines his happiness for the rest of his life. How you feel at the moment of death may appear to be a summation, but it can't erase all the other moments you have experienced during your life, any more than a person's happiness at one moment can determine how he will feel for the rest of his life.