It is a commonplace among scholars that the early Pythagoreans posited an immortal soul. The earliest source to associate immortality of the soul to the Pythagoreans unequivocally, Dicaearchus of Messana, stipulates that they held that (a) the soul is immortal; (b) it changes into other kinds of animals; (c) there is eternal recurrence; and (d) embodied animate creatures are of the same genus. A problem with Dicaearchus' account is that each of these doctrines can also be found in the dialogues of Plato. Given Dicaearchus' penchant for conflating Platonic with Pythagorean philosophy, we cannot employ this account for a historical understanding of Pythagorean psychology in a straightforward way. This chapter instead investigates Pythagorean psychology through analysis of two passages of Aristotle’s De anima that are often not brought to bear on the question. One passage draws important comparisons between the psychology of the Pythagoreans and Democritean and Ecphantic atomism, suggesting that the early Pythagoreans held a material theory of soul; by reference to arguments similar to Cebes' in Plato's Phaedo (87b-e), the other explains how a transmigratory soul could nevertheless be mortal. The early Pythagoreans are thus likely to have held that the soul is material, mortal, and transmigratory.

In this chapter the topic of the interaction between Roman law and Hellenistic philosophy in the late Republican era is introduced, with reference to earlier treatments in modern scholarship. Furthermore, preliminary issues are brought up, such as the problem of the sources, the characterisations of law and philosophy as practices – law as a practice of dispute resolution and philosophy as practiced within schools or haereseis with different outlooks -, and the role of rhetoric in the interaction.

In this chapter the influence of Hellenistic philosophy on Roman law is continued in terms of method: from Hellenistic epistemology the Roman jurists, like the grammarians, took over the notion of rule: they started to use it initially as a mnemotechnical device in order to get to grips with their growing legal output.

This chapter is about the achievement of immortality in contexts where an everlasting future for the subject is not envisaged. I start with Aristotle’s advice in the Nicomachean Ethics to ‘act as an immortal’ and argue that the talk of immortality does not derive from Aristotle’s own theories about the soul and intellect but rather should be understood with reference to the immediate dialectical context. I then relate Epicurean and Stoic discussions of immortality and ‘imperishability’ to the relevant parts of their theology. The early Epicurean tradition mentions ‘immortal goods’ that can be attained by human beings and are enough to make human beings, in the relevant ethical respect, godlike. Epicureanism contains more than one conception of these ‘goods’, although they should never be identified with either immortality or imperishability. In Stoicism the attribution of mortality and immortality is controlled by strict adherence to a Platonic definition of death (the separation of soul from body) – stricter adherence than we find in the Phaedo itself.

When ancient philosophers describe the fate of the soul or the human being after death, in which cases should we attribute to them a theory of immortality? When their texts describe people – or their souls, parts, or possessions – as being or becoming ‘immortal’, what does the word mean? The research brought together here explores these questions. Whether or not we should stipulate the meaning of immortality depends on which question we are addressing. The first question is about our own use of the words ‘immortal’ and ‘immortality’ when reading and trying to understand ancient theories, and here it may be appropriate to set down that ‘immortal’ means, for example, everlasting. That is how Phillip Horky understands ‘immortal’ and ‘immortality’ in his chapter on whether Pythagorean theories of reincarnation (or, as it is also called, the transmigration of souls) require souls to be everlasting.

Whereas in the previous chapters the influence of law on philosophy is brought up, this chapter deals the influence of law on philosophy, with regard to method. Already within early Hellenistic philosophy a shift of focus can be discerned from a virtue-centered to an action-orientated approach: in the 3rd century BCE the early Stoics had become interested in questions about the ‘appropriate actions’ that can be derived from these virtues. In the 2nd century BCE, inspired by the Roman jurists, the Roman Stoics became interested in the concrete applications of such actions or – put differently – introduced casuistry into philosophy.