Skumin elaborated on the theosophical conceptions of spiritual evolution, he proposed a definition and classification of Homo spiritalis (Latin: "spiritual man"), the sixth root race, consisting of eight sub-races (subspecies): HS0 Anabiosis spiritalis, HS1 Scientella spiritalis, HS2 Aurora spiritalis, HS3 Ascensus spiritalis, HS4 Vocatus spiritalis, HS5 Illuminatio spiritalis, НS6 Creatio spiritalis, and HS7 Servitus spiritalis.