In a system that emphasises individual virtue and self-mastery, duty and obligation might seem inessential to Stoic ethics. In opposition to this view, V. argues that duty was central to Stoic ethical theory. In clear and concise prose, this book discusses a wide range of topics – from the correct meaning of τὸ καθῆκον, to the absence of strict rules in Stoic ethics, to the Stoic method of deliberation, to Immanuel Kant's relationship to the Stoics. The concept of duty holds this discussion together, with intriguing results that will be of interest to philosophers, classicists and Stoic enthusiasts.
The foundation of this study is the term τὸ καθῆκον, which in philosophical discussions of Stoic ethics is often translated as ‘appropriate action’, ‘befitting action’ or ‘proper function’. Examples of Stoic καθήκοντα include non-human animal activities, self-focused actions such as taking care of one's health and other-directed actions such as honouring one's parents and country. Given the many different types of καθήκοντα, some of which fall outside the concept of moral duty, non-prescriptive translations are often preferred. Against this orthodoxy, V. argues in Chapter 1 that prescriptive translations, such as ‘duty’ and ‘prescribed action’, are better. In a philological investigation of καθήκειν in pre-Stoic Greek (abbreviated in the first chapter, but presented in full in Appendix 1) V. argues that constructions with forms of this verb are mostly used to refer to something obligatory, often handed down from an authority. After defending a novel interpretation of Zeno's proposed etymology of καθῆκον (reported by D.L. 7.108), V. concludes that the Stoics adopt this prescriptive sense of the word. While the defence of understanding non-human animal καθήκοντα as actions prescribed by nature is perhaps too brief (p. 19), the philological case for prescriptive translations of καθῆκον in relation to humans is compelling and should reopen debate on this topic.
Since doing one's καθῆκον is central to Stoic ethics and since one's καθῆκον is one's duty, one might imagine an ideal Stoic as a perfect follower of the rules. Against this picture, in Chapter 2, V. argues that, despite deontology's tendency towards rule-following, the Stoics deny that rules can define the right action in all situations. He explains how ‘in a dire circumstance’ (his translation of κατὰ περίστασιν, defended persuasively on pp. 42–4) even gruesome acts can become one's duty.
Given the Stoics’ rejection of universal rules, one might ask how one should discover one's duty. In Chapter 3 V. initiates this inquiry by investigating the concepts of formula in Cicero and Seneca and δόγμα in Epictetus and Marcus Aurelius. A formula turns out to be a group of claims (Epictetus and Marcus' δόγματα) about the nature of the world and one's place in it: in summary, human beings are parts of a greater whole, and one's personal interests align with that of the whole. Keeping this formula in mind helps when one faces ethical dilemmas. But this only assists with one aspect of late-stage deliberation; Chapter 4 investigates all stages. In a wide-ranging discussion of deliberation in Cicero, Seneca and Epictetus (as well as fragmentary evidence for the early Stoics) V. argues that the Stoics had advice for every stage of deliberation. For example, in an insightful discussion of Cicero's ‘four personae’ from De officiis (pp. 87–94) V. shows that decorum and morality coincide. Consequently, one can determine the seemly action (based on an evaluation of one's ‘roles’ or personae) to discover the morally correct action.
In the book's final two chapters V. evaluates the relationship of Kant to the Stoics. Chapter 5 contains a biographical account of Kant's knowledge of ancient philosophy (pp. 102–9) and argues that the Stoic account of practical deliberation has much in common with Kant's (pp. 110–18). Chapter 6 turns to the relationship of Kantian duty to the Stoic καθῆκον. The most striking discussion in this final chapter focuses on Kant's ‘Humanity’ formulation of the Categorical Imperative and its similarity to V.'s account of the Stoic formula (pp. 128–32). V. even suggests that Kant could have been influenced by Cicero's account of Stoicism (p. 130), though the ‘main objective’ of this chapter is to note similarities between Stoic and Kantian deliberation. Two appendices complete the book – the first already mentioned, and the second comprising original translations of D.L. 7.108–10 and Stobaeus 2.7.8.
The ambitious scope of this work is commendable. V. connects our fragmentary understanding of Stoicism to its reception in eighteenth-century Prussia. In doing so, he makes the case that the Stoics had more in common with modern ethics than one might suspect. My remaining discussion focuses on these issues.
The book's subtitle suggests that Stoic ethics can be understood as a deontological theory. Certainly, V. has demonstrated that later Stoics share much in common with deontologists like Kant in terms of practical deliberation. He also argues compellingly in favour of prescriptive translations of τὸ καθῆκον. However, one might doubt that this establishes Stoicism as deontology. Many ethical theories could adopt the trappings of deontology: one might imagine a consequentialist arguing that it is one's duty to maximise the good and that we discover this through internalising the interests of the whole of which we are parts. Still, a consequentialist is not a deontologist. The fact that the Stoics are rational eudaimonists who maintain that all reasons for action are justified relative to an agent's personal happiness (Stobaeus 2.7.6e) challenges the understanding of Stoicism as deontology. Deontological theories (if nothing else) are committed to the claim that one's moral obligations might come apart from one's own interests. Discussions of the Stoics in relation to Kant circle these issues, but V. admittedly focuses on how one deliberates rather than the underlying structure of ethical theories (pp. 115–18).
V. emphasises that the καθῆκον is authoritative: an action is someone's duty when it is demanded of them. The relationship between authority and duty also seems relevant to these issues. Despite the book's focus on later accounts of deliberation, there is one early Stoic account reported by Epictetus (Diss. 2.6.9–10). The third Stoic scholarch, Chrysippus, says: if you know what is fated for you, form an impulse to bring about this fate; if the future is uncertain, do things that will secure the ‘things according to nature’. V. interprets this as a recommendation that one should act for the sake of the whole in dire circumstances (p. 73). However, Chrysippus seems instead to focus on the authority of god and the benefits we can secure from him: since god has made me disposed to select certain things, it is in my interest to do so; he will give me a sign if I should do something else. Chrysippean deliberation thus might turn out to be the process of discovering what I have most reason to believe is fated of me (see J. Klein, ‘Making Sense of Stoic Indifferents’, OSAP 49 [2015]). Since aligning one's will with god's is in one's interest, the normative authority of god and duty seems to originate in one's own happiness. Thus, in some sense, it is my happiness that demands that I perform my duty. Again, the egoism of Stoicism undermines the thesis that it is a form of deontology.
Still, this work describes many similarities between Stoicism and deontological ethics. V.'s philological discussions and his descriptions of Stoic deliberative methods offer fresh arguments and analyses that specialists will find valuable. Stoic enthusiasts should find the detailed treatments of deliberation in the middle chapters compelling and readable. Thus, this book makes a valuable contribution to our understanding of ancient Stoicism, even if Stoicism is not deontology.
