Etruscan religious theory divided thunderbolts into distinct types assigned to different gods, a detailed lightning theology preserved for later readers chiefly through Roman writers describing Etruscan divinatory learning, and Menrva held a recognized place within this scheme. The Roman philosopher Seneca, discussing Etruscan beliefs about lightning in his Natural Questions, reports that Etruscan doctrine, the disciplina Etrusca, recognized eleven distinct types of thunderbolt distributed among nine gods, with the sovereign sky god Tinia alone entitled to wield three different kinds of bolt, ranging from a mild warning strike to a devastating, world-altering one, while other deities including Menrva were credited with the power to hurl a single specific type each, a systematic theological classification of a natural phenomenon considerably more elaborate than anything in the Greek or Roman thunderbolt traditions surrounding Zeus or Jupiter.
This lightning theology connected directly to the practical work of the haruspices, the Etruscan diviners who read thunderbolts as omens according to which god had sent them, where they struck, and what type of bolt was involved, a system requiring specialists to memorize which portion of the divided templum, the sky map used in divination, belonged to which deity's characteristic lightning. Menrva's inclusion among the nine lightning-wielding gods, alongside her better attested roles in craft, war and healing, shows that even a goddess primarily received by later ages as an Etruscan Athena carried a distinctly local, technical function within Etruscan religious science that has no straightforward Greek equivalent at all.