Man's desire has no end. He wants both. What a possible for him to achieve and what is impossible. He wants,in most of cases, moreover ,as he get something, he understands how nice it is so possess it. This proud felling makes him more deairous. At momment this desire turns into greed. And a need,as a scholar has remarked, can be satisfied greeds never. If this is the reality, then how can his greeds be satisfied?Rather,his greeds go on building up.