The book presents the most significant works of the great Russian physiologist, Nobel Prize laureate I.P. Pavlov (1849-1936), who made a huge theoretical and practical contribution to world science in the field of studying the physiology of blood circulation, digestion and higher nervous activity. Having discovered conditional reflexes and studied them, Pavlov developed a method of physiologically objective study of mental processes. Behind the detailed reports on the experiments is the long and painstaking work of both Academician Pavlov himself and his many employees and students, carried out with enthusiasm in the name of serving scientific ideals. Even though science has already gone far ahead, these works will always be in demand, since they form the basis of modern physiology and medicine. And lectures of a socially critical orientation, which are usually combined under the title "About the mind in general, about the Russian mind in particular," reveal other facets of Pavlovsk genius, showing him as a philosopher and analyst.