To Have or To Be? The Nature of the Psyche, by Erich Fromm (German-American psychologist, sociologist, and philosopher)

Having and being are two very different ways of life. In the having way of life, people always need to possess external goods to prove that their existence has meaning. The being way of life encourages that one takes an active role in developing things and oneself in a way that makes life more meaningful. What's the difference between these two lifestyles? How do societies based on each of these two lifestyles differ? Which should we choose?