Psychological Sunnah for the development of nations

A book on sociology of the French historian Gustav Lebon, in which he deals with the characteristics of psychological veins, the limits that change with their morals, the spirit of veins and how to derive systems from them, their historical composition and the system of their ranks. It deals with the gradual disparity of individuals in the veins system, and discusses how psychological morals are evident in various elements of civilizations, which are an external appearance of the spirit of the nation, and how to transform systems, religions, languages ​​and arts. Gustav discussed the derivation of the history of nations from its morals, and presented an application to derive systems from the nation''s spirit on the comparative research in the development of the United States of America and the Spanish Republics, and the role of changing the spirit of veins in the development of nations throughout history. He indicated that each race has a psychological feature inherited, as he inherits biological characteristics, where individuals inherit the psychological mood of their predecessors. The book touched on the influence of ideas on the lives of nations, the role of religious beliefs in the development of civilizations, and the role of the great men in it. Then he searches for the dissolution and degradation of the ethics of the veins, and the reasons that led to extinguishing the flame of ancient civilizations throughout history.