In Matter and Consciousness, Paul Churchland clearly presents the advantages and disadvantages of such difficult issues in philosophy of mind as behaviorism, reductive materialism, functionalism, and eliminative materialism. Churchland organizes and clarifies the new theoretical and experimental results of the natural sciences for a wider philosophical audience, observing that this research bears directly on questions concerning the basic elements of cognitive activity and their implementation in real physical systems. (How is it, he asks, that living creatures perform some cognitive tasks so swiftly and easily, where computers do them only badly or not at all?) Most significant for philosophy, Churchland asserts, is the support these results tend to give to thereductive and the eliminative versions of materialism.