M. Tulii Ciceronis de natura deorum libri tres

De Natura deorum (The Nature of the Gods) is a philosophical dialogue by Roman orator Cicero written in 45 BC. It is laid out in three books, each of which discuss the theology of different Roman and Greek philosophers. The dialogue uses a discussion of Stoic, Epicurean, and skeptical theories to examine fundamental questions of theology.

The dialogue is on the whole narrated by Cicero himself, though he does not play an active part in the discussion. Gaius Velleius represents the Epicurean school, Quintus Lucilius Balbus argues for the Stoics, and Gaius Cotta speaks for Cicero's own Academic skepticism. The first book of the dialogue contains Cicero's introduction, Velleius' case for the Epicurean theology and Cotta's criticism of Epicureanism. Book II focuses on Balbus' explanation and defense of Stoic theology. Book III lays out Cotta's criticism of Balbus' claims.