The purpose of this course of lectures was to show how events occurring in the spiritual worlds affect all areas of people's lives, including individual human health. As a result of the battle between Archangel Michael and Ahriman in the 19th century, the spiritual world was cleansed, and the demonic host was cast into the world of people. Using specific examples from cultural, social and political life (events in Russia in 1917 are also considered), R. Steiner shows how demonic creatures bring destruction, chaos and rejection of truth into the human spiritual world. People who fall under their influence, in particular, lose the ability to connect facts into a single picture, and the masses of people acquire a tendency towards nationalistic manifestations. The author sees the possibility of countering dangerous destructive tendencies in overcoming the materialistic nature of thinking, properly raising children and bringing events in the spiritual worlds to the consciousness of people.