Three methods for affect investigation are being presented: the method of psychopathology and phenomenology, the method of behavior theory and the method of psychoanalysis. From the phenomenological point of view affects are poorly covered by nosography. In the classical texts of former psychiatry they obviously play a more prominent role in the characterization of schizophrenic disorders. Affects were by definition no object of study in behaviorism. However, after the cognitive and emotional turn in behavior theory they are increasingly subject to theoretical and therapeutic claims. In psychoanalysis, affects were considered from the beginning to be a part of psychic representation of drive energy. Their change in psychoses may be related to psychotic change of drive energy. Starting from the task of economy of libido, affects received a widening of their significance within the development of psychoanalysis, in an additional sense of autonomous modality of the unconscious as well as emphasizing their signalling character and their impact on communication.Comprehensive theories of affect are yet still missing in psychiatry and in psychology. As the number of theories of personality grows, considerations in the field of philosophy of science are becoming even more important in order to achieve the required method safety.