In the fifth century B.C., Empedocles of Acragas, the Greek philosopher, proclaimed that the universe is composed of four primal elements: fire, air, water, and earth. While not, perhaps, the most scientific descriptive cosmology, this doctrine nevertheless dominated Western philosophical thought for twenty-one hundred years and is today still favorably regarded by born-again astrologists. But it did not fully satisfy Aristotle, who, writing a century later, explained that while these four material elements could define all earthly substances, a fifth immaterial element must define all heavenly phenomena. He called this element pemte ousia, or FIFTH BEING
