This study of Western philosophic systems, their types, history, relations, and projected future in the next half century, stems from Robert S. Brumbaugh s forty-year fascination with the paradox of the many consistent overarching systems of ideas that are nevertheless mutually exclusive.Brumbaugh argues that when we isolate these systems s patterns and look at them more abstractly, they consistently fall into four main types, and the interaction of these four types of explanation and order is a dominant theme in the history of Western philosophy.In Brumbaugh s view these four philosophic systems are not, as some critical historians and thinkers have claimed, so different that they are mutually unintelligible, forcing us to make a choice among them that is entirely arbitrary. But neither are they, as a majority of past thinkers and historians have hoped, simply parts of some single "right" or "orthodox" scheme. Their mutual understanding requires a method of transformation that interprets one to another without destroying their diversity.The history of Western philosophy from the fifth century A.D. to the present shows a pattern of alternating revolutions in systematic method and direction of explanation. Brumbaugh feels that the pattern is continuing in a change toward a revised Platonism, just beginning with the twenty-first century. He anticipates that it will be a Platonism of a new texture, one that has matured and learned a great deal in the course of the adventures of its ideas through space and time."