Western philosophy has generated a rich mosaic of theory about the nature of the world and humanity's place in it. Since the ancient Greeks, the search for the fundamentals of existence has led to the espousal of philosophical idealism (unchanging conceptual universals) on the one hand and an equally immutable (irreducible) physical materialism on the other. For centuries the tension between these views of the world has stimulated all philosophical inquiry. Today the debate remains as lively as ever.<BR>In Materialism: An Affirmative History and Definition Richard C. Vitzthum focuses on one side of this longstanding debate to offer the first comprehensive history and re-definition of materialist philosophy in more than a century. His is the first study ever to identify and analyze in detail the three masterpieces of pre-20th-century materialist literature: Lucretius' The Nature of Things (ca. 50 B.C.E.); Paul d'Holbach's 1770 System of Nature; and Ludwig Buechner's 1884 edition of Force and Matter. What's more, it is the first effort to evaluate 20th-century materialist literature in terms of the tradition as a whole.<BR>But Materialism is far more than intellectual history; it represents the first systematic effort to bring traditional materialism in line with the discoveries of modern physics. By substituting relativity and quantum theory for Newtonian mechanics, Vitzthum affirms that everything in the cosmos, including human consciousness, is explicable in terms of natural laws and reducible to fundamental principles of nature. But he posits a probabilistic materialism to replace the mechanistic determinism of d'Holbach and Buechner.