In book 1.11-20 of De Officiis, Cicero draws on the work of Panaetius to give an account of how the most basic, in-built features of human nature provide a foundation for the cardinal virtues. His account begins from the basic drive for self-preservation which is the usual starting point for the canonical Stoic doctrine of oikeiōsis. The developments that Cicero claims follow from this fundamental starting point are, however, quite different from those which ensue on the other preserved accounts of oikeiōsis, such as that reported for Chrysippus in Diogenes Laërtius 7.85-86, the account in Cicero’s De Finibus 3.16-25 and the one in letter 121 of Seneca. It is also importantly different from the more complex account attributed to Posidonius by Galen in On the Doctrines of Plato and Hippocrates 5.5.8-9. By comparing and contrasting Cicero’s theory in the De Officiis with these other accounts, this chapter will explore important facets of Cicero’s philosophical method, his originality in adapting Panaetius’ theory to his own purposes, and the merits of the novel doctrine he embraced in his final philosophical work.

The chapter is devoted to the work of Posidonius in all its aspects and argues that he created a second major synthesis of Stoic thought, expanding the school’s attention to the sciences and history while making innovations in logic, physics and ethics. Argues that Posidonius was a more conservative Stoic than is often thought.

Chapter 4 of De mundo concludes the first, ‘scientific’ part of the treatise, which contains a description of the universe. Chapter 4 deals with the phenomena that belong to the science of meteorology as the ancients understood it, which included not only all kinds of precipitation, cloud formations, wind and thunder, but also phenomena such as shooting stars, earthquakes, tides and volcanic eruptions. Chapter 4 of De mundo shows similarity with Aristotle’s Meteorology in theory and general structure, but there are notable differences – the construction of the wind rose, omission of the Milky Way, and the inclusion of a lunar tide theory – which seem to indicate another source for this chapter. This is also indicated by the compendium style of Chapter 4: instead of offering causal explanations of the meteorological phenomena, the author proceeds by dividing them into groups and then briefly describing each member of every group. Some scholars have argued that the source of this chapter of De mundo is Posidonius’ treatise on meteorology. Despite some striking similarities, reasons are given against accepting this thesis. It is suggested that an earlier compendium of meteorology, combining Peripatetic and Stoic elements, was the principal source of Chapter 4 of De mundo.

The author of De mundo offers his outline of geography in the second part of Chapter 3. In this contribution, we look at the details of the author’s account and analyse it in the context of the historical development of ancient geographic ideas. There is a number of indications that the text can be dated to later Hellenistic times: the author’s view on the insularity of the inhabited world, on the nature and role of the ocean and its connection with the Caspian/Hyrcanian Sea, on the borders between the continents and on the calculation of the dimensions of the inhabited world (oikoumenē). We argue that the author might have been influenced by the treatises on the ocean as a literary model for this section of De mundo. We know that authors such as Pytheas of Massalia, Posidonius of Apamea and Athenodorus of Tharsus wrote works under the title On the Ocean, which survive only in scarce fragments. The information we can extract from De mundo in this respect is, therefore, invaluable for a reconstruction of the content, circulation and reception of this sub-genre of geographic literature in the last decades of Hellenism.

This chapter traces a genealogy of pneumatic cosmology, covering the Pythagoreans of the fifth century BCE, the Stoics of the third and second centuries BCE, the Jews writing in Alexandria in the first century BCE and the Christians of the first century CE. Starting from the early Pythagoreans, ‘breath’ and ‘breathing’ function to draw analogies between cosmogony and anthropogony – a notion ultimately rejected by Plato in the Timaeus and Aristotle in his cosmological works, but taken up by the Posidonius and expanded into a rich and challenging corporeal metaphysics. Similarly, the Post-Hellenistic philosopher and biblical exegete Philo of Alexandria approaches the cosmogony and anthropogony described in Genesis (1:1-3 and 1:7) through Platonist-Stoic philosophy, in his attempt to provide a philosophically rigorous explanation for why Moses employed certain terms or phrases when writing his book of creation. Finally, the chapter sees a determined shift in the direction of rejecting pneumatic cosmology for a revised pneumatic anthropogony in the writings of the New Testament: by appeal to the ‘Holy Spirit’ (πνεῦμα ἅγιον), early Christians effectively adapted the Stoic metaphysics of ‘breath’, with its notions of divine intelligence and bonding, to the ecclesiastical project of building a Christian community conceived of as the ‘body of Christ’.