Otto Fenichel's highly significant essays explore many subjects that were only touched on in his books. Many of these discussions, present-day classics in their fields, are comprehensive monographs in themselves. Often so much is brought to bear on the central topic from so many sources, and then related so clearly to the context, that these essays become works of reference for a much larger field. It is a contribution of the greatest value to preserve and make conveniently available so much that is intensely useful from the life work of this remarkable man.