Two principal approaches to surveying the field of psychology are the historical and the systematic. Most major university psychology departments require their students to study both the historical development of psychology and the chief distinguishing features of some major psychological theories. Historical study of the field is assisted by several superb texts, among which are Boring's History of Experimental Psychology and Murphy's Historical Introduction to Modern Psychology. There are no comparable surveys of systems of psychology. Benjamin Wolman, a teacher of psychology who has also had experience in clinical work and research, set himself the task of writing a definitive exposition of current theories and systems in psychology. His is an ambitious undertaking. He divides contemporary psychological systems into three families, each with an inspirational father: Pavlov, Freud, and Dilthey. Part one considers mainly the psychology of learning as influenced by Pavlov and