While the preceding two chapters focused on the physiological domains whose motions take place ‘by nature’, that is, involuntarily, this chapter looks at the activities of the physiological system responsible for the motion ‘by will’. Galen depends on Hellenistic anatomists, especially Herophilus, for much of what he knows about the nervous system, but this chapter looks at both inherited knowledge and polemic interaction. In a rare case of disagreement, Galen criticizes Herophilus regarding the claims about the inherent sensitivity of the nerve tissue. The fact that Galen does not accept Herophilus’ experiments and maintains that nerves only receive capacity from the brain shapes his understanding of this physiological domain. The activities of the nervous system encompass not only voluntary motion but also sense perception and pain, and this chapter argues that each of them has distinctive implications for the unity of the living body as a whole.

This chapter deals with the cardiac system that underpins animal vitality that is more complex than the vegetative one discussed in the previous chapter. The central activity of this system is breathing, and the chapter outlines different types of breathing posited by Galen, the anatomy underpinning them, and his explanation of why the deprivation of breath leads to the loss of life. The chapter also focuses on the three types of pneuma theorized by Galen, discussing their proper activities and properties enabling these activities. The focus on pneuma also brings attention to yet another Galenic division of parts into solids, fluids and pneumata. This division of tissues according to their texture and speed of movement offers an important glimpse into how Galen conceives of interaction between parts. Moreover, the rapid alterations in the pneumatic tissues underpin the physiological understanding of animal vitality.

Tusculans 1 offers a multi-faceted refutation of the proposition ‘death is an evil’, accomplished in part through a detailed doxography of a wide range of philosophers of different schools. This survey is far from a jumble of contradictory views, however: Cicero avoids dogmatic insistence on the arguments of any single school and has instead crafted a minimally sectarian protreptic designed to convince readers of any philosophical persuasion that death is not an evil, an approach whose origin he traces back to Socrates’ reflections on death in Plato’s Apology. Furthermore, I argue that this approach amounts to a direct challenge to Cicero’s philosophical rivals, a group of Epicurean authors writing in Latin – including, I speculate, Lucretius – whom Cicero had criticiaed in several prefaces for their narrow-minded dogmatism. In Book 1 Cicero therefore tackles a topic of perennial interest, illustrates how philosophy can and should be written, and attempts to marginalise his Epicurean opponents.

In Tusculans 1 Cicero gives a lengthy rebuttal of the thesis that death is an evil. This raises a puzzle: how can such a one-sided presentation aspire to reveal whether it is more plausible that death is or is not an evil? Invoking the Tusculans’ practical aim – the removal of emotional disturbance – does not fully satisfy, since it is unclear how effective persuasion can be if the contrary position does not receive a fair hearing. I show that as main speaker in the book Cicero warns against over-confidence in embracing positions that one wishes to be true; and I argue that as author Cicero portrays the interlocutor of Tusculans 1 as a salutary example of how not to approach the kind of questions about death with which the work engages. We are encouraged to see the interlocutor’s failure as one not of character but of inexperience in philosophical method.

The definitions of the emotions in Cicero’s Tusculan Disputations 3 which refer to magnitude are not meant to represent Stoic orthodoxy, and should not be read as direct evidence for the Stoic theory. Cicero’s aims and methods in the Tusculans led him to use non-Stoic accounts of the emotions, in order to offer a kind of consolation that is neutral between Stoic and Peripatetic theories of value. This chapter also discusses the structure of the Tusculans as a unified whole.

The final book of the Tusculans is intended to bring together the results of the preceding books in two ways. It concludes the argument that virtue is sufficient for happiness, where that is understood as invulnerable tranquillity and peace of mind. The book also fills out its opening praise of philosophy, understood as Academic sceptical method. However, the forceful final coda raises problems of philosophical consistency which, when examined carefully, cannot be reconciled with the book’s initial aims.

In Tusculans 2 the interlocutors discuss the value of physical pain. They swiftly agree that it is not the greatest evil but take longer to consider whether it is bad or, as the Stoics think, merely indifferent. Enduring pain is taken to be an indication of courage and manliness (virtus) and this is undermined by the claim that physical pain is not bad. Therefore neither the Epicureans nor the Stoics provide a wholly satisfactory account of the value of physical pain and its relationship to virtue.

This chapter focuses on Cicero’s treatment of the emotions in Books 3 and 4, and more specifically on his account of the dispute between the Stoics and the Peripatetics. At first sight, the dispute seems uncomplicated: the Stoics advocate the complete absence of emotions whereas the Peripatetics hold that emotions should rather be moderated or controlled. But Cicero’s stress on the idea that emotions are beliefs seems to come at the expense of other central parts of the theory of emotions, most prominently the theory of action.  I argue that these features of his presentation serve him in securing a thesis that he is keen to defend in Book 5: that virtue guarantees happiness and that this happiness is invulnerable to the accidents of fortune.

An introduction to the historical and philosophical context of Cicero’s Tusculan Disputations and an overview of some general questions to be investigated in the volume, particularly: the question of Cicero’s ‘Socratic method’, his use of dialogue, his claim to argue on both sides of a question, and the relationship between this and his Academic scepticism.

The Tusculan Disputations can be read as a complex of four projects: (1) a set of formal exercises in the schola genre; (2) a therapeutic operation directed against the emotions, and fear in particular, with an agonistic relation to Epicurean predecessors; (3) a project of edification, aiming to reinforce the reader’s commitment to virtue; and (4) an exhibition or advertisement of the powers of philosophy and its advantages to Rome. Together, these dimensions of the Tusculans explain the peculiarities of its argumentation and literary approach. It is plausibly the aspiration to advertise philosophy to Rome (4) which is most fundamental: therapy (2) and edification (3) are projects in which philosophy can usefully display its powers, and the schola form (1) is convenient for doing so. These projects are to be distinguished from that of philosophical inquiry; the Tusculans is informed more by Cicero’s patriotic pragmatism than by his scepticism.

The aim of this chapter is to investigate the teaching of the so-called Peripatetics in the Tusculan Disputations with regard to their views on passions. Such views serve Cicero’s dialectical purposes and his wish to present the debate in Books 3–5 as primarily a dialectical exchange between Stoic ‘lack of passions’ (apatheia) and Peripatetic ‘moderation of passions’ (metriopatheia). Moreover, the Peripatetics are presented as siding with the early followers of Plato, and in particular with Crantor, in a unified camp against the Stoics. I argue that, despite the polemical features of Cicero’s presentation of the Peripatetics in the work, the metriopatheia view merits serious consideration, being much more than just a foil for an argument in favour of Stoicism.