Cicero's De Natura Deorum

On the Nature of the Gods by Cicero is written as a dialogue between Cicero and representatives from Epicurean, Stoic and Academic Sceptic schools. Book 1 contains the discourse of Velleius – a Senator and Epicurean – which consists of three parts: a general attack on Platonist and Stoic cosmology; a historical review of the earlier philosophers; and an exposition of Epicurean theology.