many historically known groups speaking Indo-European languages show such a division. Dumézil initially contended that it derived from an actual division in Indo-European societies, but later toned down his approach by representing the system as fonctions or general organizing principles. Dumézil's theory has been influential and some scholars continue to operate under its framework, although it has also been criticized as aprioristic and too inclusive, and thus impossible to be proved or disproved. Culture Beliefs The reconstructed cosmology of the proto-Indo-Europeans shows that the ritual sacrifice of cattle, cows in particular, was at the root of their beliefs, as the primordial condition of the world order. The myth of *Trito, the first warrior, involves the liberation of cattle stolen by a three-headed serpent named *Ngwhi. After recovering the wealth of the people, Trito eventually offered the cattle to the priest in order to ensure the continuity of the cycle of giving between gods and humans. The creation myth could have rationalized raiding as the recovery of cattle that the gods had intended for the people who sacrificed properly. Many Indo-European cultures preserved the tradition of cattle raiding, which they often associated with epic myths. Georges Dumézil suggested that the religious function was represented by a duality, one reflecting the magico-religious nature of priesthood, while the other is involved in religious sanction to human society (especially contracts), a theory supported by common features in Iranian, Roman, Scandinavian and Celtic traditions. The study of astronomy was not much developed among Proto-Indo-Europeans, and they probably had established names for only a few individual stars and star-groups (e.g. Sirius, Ursa Major). The basic word for "god" in proto-Indo-European is *deiwós ("celestial"), itself a derivative of *dei- ("to shine, be bright"). On the other hand, the word for "earth" (*dʰéǵʰōm) is at root of both "earthly" and "human", as it is notably attested in the Latin cognates humus and homo. This suggests a hierarchical conception of the status of mankind regarding the gods, confirmed by the use of the term "mortal" (*mr̩tós) as a synonym of "human" as opposed to the never-dying gods in Indo-European traditions. The idea is expressed in the Homeric phrase "of the immortal gods and of men who walk on earth". Proto-Indo-European beliefs were influenced by a resistant animistic substratum, and the few names that can be reconstructed based upon both linguistic (cognates) and thematic (reflexes) evidence are the cosmic and