I do not think of myself as primarily interested in method, but in the substance of psychology. Nevertheless, our discipline has such difficulties in coming to grips with its substance that I have found myself getting involved in fww to do it persistently and since the beginning of my career. That career has been divided between diagnosis and research, the balance between them swinging gradually from the former to the latter. To the astonishment of many of my students and colleagues, I have never become a psychotherapist nor a psychoanalyst, though I have looked closely over the shoulders of many friends at their work, have attended continuous case seminars, and have participated in research on psychotherapy and psychoanalysis enough to feel that I have a pretty good grasp of what that kind of endeavor is like. So I have been writing about method, diagnostic and investigative, for over 25 years, and was happy to accept the suggestion of Seymour Weingar ten, of Plenum Press, that I publish a collection of these papers. What has ended up as two volumes was originally conceived as one, for I feel that there is more similarity of method in assessment, prediction, and research than appears on the surface. The General Introduction and Chapter 1 of Volume 1 state the point of view of the entire work.