French psychologist and psychiatrist who made significant contributions to psychology by creating a general theory of behavior and developing methods of psychotherapy. He studied neuroses, proposed the concepts of “mental automatism” and “psychasthenia”, and also developed a hierarchical system of forms of behavior, from simple reflexes to complex intellectual actions. In the 1920s and 1930s, Janet turned to the construction of a general psychological theory, within the framework of which almost all mental phenomena received their interpretation. Considering psychology as a science “about the facts of consciousness,” Janet believed that psychology should be “objective in the sense that its subject should be the directly observable…” At the same time, Pierre Janet tried to avoid the extremes of behaviorist approaches, noting that it is necessary to consider consciousness “as a special form of act, tuned to elementary behavior…” He developed a whole hierarchical system of various forms of behavior from elementary reflex acts to higher intellectual actions. His work influenced L. S. Vygotsky and became the basis for phase-oriented approaches to the treatment of PTSD.