The article is devoted to the outstanding Canadian scientist, the discoverer of the general adaptation syndrome (stress-reaction) to Hans Selye. The biographical data of the original thinker who changed the previous ideas about the phases of the development of pathological processes and deepened the understanding of the laws of the work of various functional systems of the body are given. The history of the appearance and the essence of the term “stress”, the general adaptive syndrome and the main stages of its study were described, the role of researchers — the predecessors of H. Selye
(K. Bernard, W. Kennon) was noted. The positive role of acute stress was noted. The revolutionary and significance of the concept of stress for biology and medicine is emphasized. The views of H. Selye on the methodology of research work are characterized. Attention was paid to the system of ethical provisions (code of morality) of the scientist, the inconsistency of his views in the field of social relations was noted. The studies of H. Selye have turned into a doctrine of stress, which is actively developed all over the world.