Theology

Sources

Marcus Terentius Varro and Verrius Flaccus^[158] were the main sources on the theology of Jupiter and archaic Roman religion in general. Varro was acquainted with the libri pontificum ("books of the Pontiffs") and their archaic classifications.^[159] On these two sources depend other ancient authorities, such as Ovid, Servius, Aulus Gellius, Macrobius, patristic texts, Dionysius of Halicarnassus and Plutarch.
One of the most important sources which preserve the theology of Jupiter and other Roman deities is The City of God against the Pagans by Augustine of Hippo. Augustine's criticism of traditional Roman religion is based on Varro's lost work, Antiquitates Rerum Divinarum. Although a work of Christian apologetics, The City of God provides glimpses into Varro's theological system and authentic Roman theological lore in general. According to Augustine,^[160] Varro drew on the pontiff Mucius Scaevola's tripartite theology:

• The mythic theology of the poets (useful for the theatre)
• The physical theology of the philosophers (useful for understanding the natural world)
• The civil theology of the priests (useful for the state)^[161]

Jovian theology

Georg Wissowa stressed Jupiter's uniqueness as the only case among Indo-European religions in which the original god preserved his name, his identity and his prerogatives.^[162] In this view, Jupiter is the god of heaven and retains his identification with the sky among the Latin poets (his name is used as a synonym for "sky".^[163]) In this respect, he differs from his Greek equivalent Zeus (who is considered a personal god, warden and dispenser of skylight). His name reflects this idea; it is a derivative of the Indo-European word for "bright, shining sky". His residence is found atop the hills of Rome and of mountains in general; as a result, his cult is present in Rome and throughout Italy at upper elevations.^[164] Jupiter assumed atmospheric qualities; he is the wielder of lightning and the master of weather. However, Wissowa acknowledges that Jupiter is not merely a naturalistic, heavenly, supreme deity; he is in continual communication with man by means of thunder, lightning and the flight of birds (his auspices). Through his vigilant watch he is also the guardian of public oaths and compacts and the guarantor of good faith in the State cult.^[165] The Jovian cult was common to the Italic people under the names Iove, Diove (Latin) and Iuve, Diuve (Oscan, in Umbrian only Iuve, Iupater in the Iguvine Tables).
Wissowa considered Jupiter also a god of war and agriculture, in addition to his political role as guarantor of good faith (public and private) as Iuppiter Lapis and Dius Fidius, respectively. His view is grounded in the sphere of action of the god (who intervenes in battle and influences the harvest through weather).Wissowa (1912), pp. 103–108
In Georges Dumézil's view, Jovian theology (and that of the equivalent gods in other Indo-European religions) is an evolution from a naturalistic, supreme, celestial god identified with heaven to a sovereign god, a wielder of lightning bolts, master and protector of the community (in other words, of a change from a naturalistic approach to the world of the divine to a socio-political approach).^[166]

One interpretation of the lightning in Giorgione's Tempest is that it represents the presence of Jupiter.^[167]

In Vedic religion, Dyaus Pitar remained confined to his distant, removed, passive role and the place of sovereign god was occupied by Varuna and Mitra. In Greek and Roman religion, instead, the homonymous gods *Diou- and Διϝ- evolved into atmospheric deities; by their mastery of thunder and lightning, they expressed themselves and made their will known to the community. In Rome, Jupiter also sent signs to the leaders of the state in the form of auspices in addition to thunder. The art of augury was considered prestigious by ancient Romans; by sending his signs, Jupiter (the sovereign of heaven) communicates his advice to his terrestrial colleague: the king (rex) or his successor magistrates. The encounter between the heavenly and political, legal aspects of the deity are well represented by the prerogatives, privileges, functions and taboos proper to his flamen (the flamen Dialis and his wife, the flaminica Dialis).
Dumézil maintains that Jupiter is not himself a god of war and agriculture, although his actions and interest may extend to these spheres of human endeavour. His view is based on the methodological assumption that the chief criterion for studying a god's nature is not to consider his field of action, but the quality, method and features of his action. Consequently, the analysis of the type of action performed by Jupiter in the domains in which he operates indicates that Jupiter is a sovereign god who may act in the field of politics (as well as agriculture and war) in his capacity as such, i.e. in a way and with the features proper to a king. Sovereignty is expressed through the two aspects of absolute, magic power (epitomised and represented by the Vedic god Varuna) and lawful right (by the Vedic god Mitra).^[168] However, sovereignty permits action in every field; otherwise, it would lose its essential quality. As a further proof, Dumézil cites the story of Tullus Hostilius (the most belligerent of the Roman kings), who was killed by Jupiter with a lightning bolt (indicating that he did not enjoy the god's favour). Varro's definition of Jupiter as the god who has under his jurisdiction the full expression of every being (penes Iovem sunt summa) reflects the sovereign nature of the god, as opposed to the jurisdiction of Janus (god of passages and change) on their beginning (penes Ianum sunt prima).^[169]