The term “Nervism” was originally coined in Russia to denote the predominant or central role that the nervous system has in the coordination of the physiological and pathological processes of organisms. A similar trend of thought emerged in Britain, which was led by Henry Head and James Mackenzie. However, meeting points between the schools of physiology of Russia and England have been traced, specifically since the sixteenth century. This chapter is based on a previous study in which a comparative analysis of the Russian school of synthetic physiology, or nervism, was carried out with the notions developed by Henry Head and James Mackenzie, identifying seven conceptual categories. These categories are developed in detail in this chapter and include the consideration of the reflex as a basic physiological unit, the role of the nervous system as a coordinator of pathophysiological dynamics, the functional continuity between the viscera and the other tissues of the segment, the overcoming of the body–mind dualism, the modes of extension and pathological generalization in the nervous system, the participation of the oral cavity in systemic health and the importance of life history.