Physiognomy of each person is a function of many factors, such as: heredity, upbringing, diet, work, thoughts, desires, the environment of cosmic influences, the whole inner world of man, etc. Changing these characteristics brings about a corresponding change in physiognomy. With "Physiognomy" an attempt is made to explain the character, mental qualities, and inclinations of man. The foundations of physiognomy were laid by Aristotle, who argued that the comparative study of human physiognomy can be successful, accurately and in detail, only among similar human types. Since then, many diagnostic methods have been discovered, which are analyzed and presented in detail and comprehensibly by the author.