Self interest is a driving force; it is motivation. Motivation leads to progression and without progression early man would never have gotten past learning about fire. There is no single purpose of self-interest, it is for the individual to decide, but it is my motivation to live and I am convinced that it raises the standards of life. All things naturally progress because they adapt. According to Darwin, the strong survive; that is, the members of a species best suited to their environment. Progress is a number of different things but it g ....