ABSTRACT
Our world consists of an enormous variety of life. We may think of it as a great family of various members. It is no random gathering; each member has a role in constituting, maintaining and developing this family. This is my fundamental view of the world. I did not always hold this view, but arrived at it gradually through years of observing and thinking about what I saw in nature. Since I shall write on the basis of this view I want to make it clear right from the beginning.
