The World soul concept in Greek philosophy

The idea of a soul of the world has played an extremely important part throughout the entire history of philosophy. And at the outset of our discussion we shall attempt to gain an understanding of what the term "world soul" implies. Dr. J. H. Tufts gives the following definition in the Dictionary of Philosophy and Psychology; "An intelligent, moving force, or directing and organizing principle, sustaining the same relation to the cosmos as the Soul or Psyche sustains to the rest of the individual." This definition will serve as a point of departure for our discussion, but we shall see later what wide ramifications the world soul concept has had under constantly changing influences in the fields of religion, philosophy and science.