only two accounts, among the ones examined by the author, are adequate for explaining physical computation. One of them is the instructional information processing account, which is developed here for the first time. "This book provides a thorough and timely analysis of differing accounts of computation while advancing the important role that information plays in understanding computation. Frescös two-pronged approach will appeal to philosophically inclined computer scientists who want to better understand common theoretical claims in cognitive science.¿ Marty J. Wolf, Professor of Computer Science, Bemidji State University ¿An original and admirably clear discussion of central issues in the foundations of contemporary cognitive science.¿ Frances Egan, Professor of Philosophy, Rutgers, The State University of New Jersey