Book iii

. Cotta criticizes the views of Balbus. The statement of the Epicurean doctrine is drawn from the work of Phaedrus [Greek: Peri theon], the criticism of this from Posidonius. The Stoic teaching is derived from Cleanthes, Chrysippus and Zeno, and is criticized from the writings of Carneades and Clitomachus.

_De Officiis_, addressed to his son Marcus. In this the form of dialogue was not employed. The material is chiefly drawn from Stoic sources, e.g. works of Panaetius in Books i. and ii., of Posidonius and Hecato in