ZEUS (Ζεός). - From a root Δυμός (cf. Skt. Dyauh), "to shine, to be bright," he is the great god of the Aryan peoples from India to Europe, the personification of the sky under its twofold aspect, astronomical and meteorological.
The universality of his conception is explained by the fact that atmospheric and celestial phenomena cannot be localized. To his fundamental Uranic character are traced all the epithets that concern him. He is the most high (ὕψιστος), the gatherer of clouds (μελανικρῆς), the hurler of the thunderbolt as he shakes the aegis (αἰγίοχος), the giver of rain (ὑέτιος) but also of fair weather (ὁρίβος, αἰθέριος). Sacred to him are the mountains from which a broader horizon of sky is revealed: typical is snow-covered Olympus, whose summit is always wreathed in clouds.
As the numen of all the Greek stocks he was a most effective instrument of their fusion, fostering a conception of the divine superior to that of the local deities, which he then proceeded to assimilate, attributing their qualities to himself as his own epithets; whence it may be said of him that he is the most Hellenic of all the gods, inasmuch as in him all the Hellenic stocks recognized themselves. Therefore he is found at the center of the moral life of the Greeks as an element of civilization, and at the center of their political and social life as an element of union.
As guardian of the moral life he is the protector of the city (πολιεός), he presides over assemblies (ἀγοραῖος), he guards the boundaries of property (ἔρχειος), he protects the stranger (ἔξχειος), he succors suppliants (ἰκέριος), he executes the will of the Moirai (Fates), that is, of fate, which is the destiny of death (μοιραγέτης) but he cannot change it (a limitation that is a homage to the idea of God, because it acknowledges the empire of a norm that counterbalances the caprice of the gods); he unites spouses (γαμήλιος), protects ties of kinship (συγγένιος), is patron of purifications (καθάριστος), of expiations (μελλίγιος) and avenger of oaths (ὄρκιος); he is the Greek numen par excellence (ἐλληνιος πανελλήνιος).
As guardian of social and political life, Z., in proportion as the fusion of regions and stocks took place, began to absorb the various local cults. Thus in Crete he is Z. Κρεταγενής, absorbing the characteristics of a local numen of vegetation that annually dies and is reborn; in Arcadia he is Z. Λυκαῖος, certainly in replacement of a very ancient animalistic cult with human sacrifice; at Dodona Z. Δωδωνίος, a local god who manifests the future through the rustling of the leaves of the oak that embodies him; Z. τροφώνιος near Lebadea in the cave of the same name, where he replaces an oracular demon; Z. Ὀλυμπέος at Olympia in Elis, around whose temple were celebrated the games that were the strongest cement of cohesion among the Hellenic stocks, and by whose quadrennial succession the years were fixed (Olympiads).
From Homer, where many of these aspects are already present, Z. appearing there as god of the thunderbolt, lord of meteorological phenomena (Iliad, X, 5, 7; XII, 252; XVII, 548-50), dweller of the mountains (ibid., VIII, 47-52; XV, 151-53; XXIV, 308), father of gods and men (ibid., XVI, 225 ff.), avenger of the oath (ibid., V, 155), executor of destiny (ibid., XXI, 82), down to Aeschylus, literature increasingly affirmed and ennobled the concept of Z., so much so that Aeschylus (frg. 345) says of him: "Z. is the ether, Z. is the earth, Z. is the sky, Z. is everything, and that which is above everything" (v. αἰονή).