 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.