Russian psychologist, made a major contribution to the creation of the concept of the reflex nature of the psyche, set forth in the work “Reflexes of the Brain”. He asserted that all mental acts, from the simplest movements to thinking, are reflexes. The significance of his works lies in the fact that he was the first to give a materialist explanation of mental phenomena, linking psychology with physiology, and laid the foundation for the further development of science. Sechenov’s ideas were developed by Vladimir Mikhailovich Bekhterev