On Duties The principal work of Panaetius was, without doubt, his treatise
On Duties () composed in three books. In this he proposed to investigate, first, what was moral or immoral; then, what was useful or not useful; and lastly, how the apparent conflict between the moral and the useful was to be decided; for, as a Stoic, he could only regard this conflict as apparent not real. The third investigation he had expressly promised at the end of the third book, but had not carried out; and his disciple
Posidonius seems to have only timidly and imperfectly supplied what was needed. Cicero wrote his own work
On Duties in deliberate imitation of Panaetius, and stated that in the third section of the subject that he did not follow Posidonius, but instead that he had completed independently and without assistance what Panaetius had left untouched. To judge from the insignificant character of the deviations, to which Cicero himself calls attention, as for example, the attempt to define moral obligation, the completion of the imperfect division into three parts, the rejection of unnecessary discussions, small supplementary additions, in the first two books Cicero has borrowed the scientific contents of his work from Panaetius, without any essential alterations. Cicero seems to have been induced to follow Panaetius, passing by earlier attempts of the Stoics to investigate the philosophy of morals, not merely by the superiority of his work in other respects, but especially by the effort that prevailed throughout it, laying aside abstract investigations and paradoxical definitions, to demonstrate the philosophy of morals in its application to life. Generally speaking, Panaetius, following
Aristotle,
Xenocrates,
Theophrastus,
Dicaearchus, and especially
Plato, had softened down the severity of the earlier Stoics, and, without giving up their fundamental definitions, had modified them so as to be capable of being applied to the conduct of life, and clothed them in the garb of eloquence. That
Cicero has not reproduced the entire contents of the three books of Panaetius, we see from a fragment, which is not found in Cicero, preserved by
Aulus Gellius, and which acquaints us with Panaetius's treatment of his subject in its
rhetorical aspects.
Other works Panaetius also wrote treatises concerning
On Cheerfulness;
On the Magistrates;
On Providence;
On Divination; His work
On Philosophical Schools appears to have been rich in facts and critical remarks, and the notices which we have about
Socrates, and on the books of Plato and others of the Socratic school, given on the authority of Panaetius, were probably taken from that work. ==Notes==