This book deals with the results of theoretical and ex­ perimental studies of the emotions which my colleagues and I carried out over the last two decades. An interest in the psychology of emotions prompted us to undertake an analysis of the creative legacy of K. S. Stanislavsky. A result of this analysis was the book, The Method of K. s. StanisZavsky and the PhysioZogy of Emotions, written in 1955-1956 and published by the Academy of Sciences of the USSR in 1962. I am grateful to the first reader and critic of the manuscript, Leon Abgarovich Orbeli. In 1960, having transferred to the Institute of Higher Nervous Activ­ ity and Neurophysiology of the Academy of Sciences of the USSR, I had the opportunity to conduct experiments on prob­ lems that had interested me for a long time. In close scien­ tific association with Peter Mikhailovich Ershov, director and teacher of theater, I began a systematic study of the in­ voluntary and electrophysiological shifts in actors during voluntary production of various emotional states. Here comparatively quickly we became convinced that the fruitfulness of such studies rests on an absence of any kind of developed, systematic, and sound generaZ theory of the emotions of man and the higher mammals. We will illustrate our difficulties if only with one example. We had frequently read of the so-called "emotional memory.