psychological investigation, and hence serves the purpose of ac- quainting the reader with significant areas of the science. The Editor is deeply appreciative of the generous assistance given by some busy psychologists. A more agreeable arrangement than that offered by the Board of Editors of the Philosophical Library could not have been desired. Except for the statement that they had every reason to expect a collection of scholarly, scientifically acceptable papers, the publishers granted complete freedom to the editors. Drs. G. L. Freeman, G. W. Hartmann, Kurt Lewin, A. H. Maslow, and C. E. Skinner served as the Board of Advisory Edi- tors. For the organization of this volume, however, the Editor assumes full responsibility. Grateful acknowledgment is here ex- pressed for their generous assistance. The Editor is indebted to the contributors and to the journal editors who graciously allowed permission for republication of their material. PHILIP LAWRENCE HARRIMAN. Bucknell University Lewisburg, Pennsylvania -vii- |