The avowed purpose of this ""cooperative book in which scientists and philosophers collaborate is, quite simply, the exploration and reformation of materialism"". The editors have avoided mechanism, general teleology, or any slant towards the establishment of vitalistic theories. The symposium starts with papers on the history of the growth of materialism, then consideration of scientific examples, on to psychological fields, economic and social aspects, philosophic concepts, finally existentialism and experience contrasted with subjectivism. The roster of contributors goes from Democritus and Plato, among the classicists, to Hegel, Marx and Engels, on to the moderns, Haldane, Roy Wood Sellars, Maurice Dobb, George Lukaes, and many others. The kind of book- a sort of materialists' Bible, a good many may buy, few will understand, and some grasshopper minds will venture to discuss. Probably inquiries should be handled by reference to the list of contributors and the Table of Contents.