Ethnographer, linguist and historian of religion Vladimir Germanovich Bogoras (Tan) (1865-1936) wrote the book “The Stages of the Development of Shamanism” in 1934-1936. The book has never been published. Its manuscript is kept in the State Museum of the History of Religion. The second part of the book is called “The Ideology of Shamanism”. A fragment from this part, which is dedicated to dualistic mythology, mainly associated with the cosmogonic views of different peoples, is presented here.