Originally published in 1977, the chapters in this volume derive from a conference on Perceiving, Acting and Knowing held by the Center for Research in Human Learning at the University of Minnesota in 1973. The volume was intended to appeal, not just to the specialist or the novice, but to anyone sufficiently interested in psychology to have obtained a sense of its history at the time. Through these essays the authors express a collective attitude that a careful scrutiny of the fundamental tenets of contemporary psychology may be needed. In some essays specific faults in the foundations of an area are discussed, and suggestions are made for remedying them. In other essays the authors flirt with more radical solutions, namely, beginning from new foundations altogether. Although the authors do not present a monolithic viewpoint, a careful reading of all their essays under one cover reveals a glimpse of a new framework by which theory and research may be guided.