He drew on mythological accounts of super-races and their decline, particularly the Hyperboreans, and maintained that traces of Hyperborean influence could be felt in Indo-European man.
Ia menggunakan mitologi ras super dan kemunduran ras tersebut, terutama orang-orang Hyperborea, dan mengatakan bahwa jejak-jejak pengaruh Hyperborea dapat dirasakan dalam manusia Indo-Eropa.