The Stoics is the plural name covering six centuries worth of philosophers, teachers and an emperor. There is a clear divide between what is known as orthodox Stoicism, epitomised by the founding trio, Zeno, Cleanthes and Chrysippus, based in Athens spanning the third century bce, and imperial Stoicism, based in Rome whose famous trio counts the advisor to emperor Nero, Seneca, a freed slave, Epictetus, and the emperor Marcus Aurelius (spanning the first and second centuries ce). The most evident point of rupture with orthodoxy is a shift in the centre of gravity of the school's concerns: less logic and an insistence on ethics and how to live well. This insistence is articulated through a panoply of tools and guidelines, which we do not find in our orthodox texts, though the core concepts that these elaborations deepen are the same core concepts that ground the ethical part of philosophy since the beginning of Stoic philosophy. The concepts of duty, right action, the injunction to rationally sift between emotional input and impressions received from reality constitute the enduring field that the imperial Stoics belabour in an expansion and self-proclaimed expatiation on orthodoxy. It is this remarkable continuity in thought and ideals which, from a bird's-eye view, smoothens out the points of rupture and which makes all Stoics stoic. And yet, were Chrysippus to meet Marcus Aurelius, it is likely he would not recognise himself in Marcus’ appeals to him. Something happens in between Chrysippus and Seneca that enacts sufficient changes for the school to transform drastically whilst, at the same, maintaining a sufficiently close adherence to core doctrine for the school to endure. As with the blurry contours of what is called Middle Platonism, there is a Middle Stoicism that marks a cultural moment, rife with small-scale revolutions, contaminations from other schools and sincere interpretations of the forefathers leading to deep transformations. If we have a scant amount of reliable sources for orthodox Stoicism, the textual situation is even worse when it comes to the shadowlands of second century bce Middle Stoicism. Out of these, two familiar names serve as figures of authority: Panaetius, the last known head of the Stoic school at Athens, whose years spent in Rome within the elite circle of Scipio Aemilianus geographically paves the route for Stoicism's transhumance from Athens to Rome; the second, Posidonius, his most famous student, who settled in Rhodes after following Panaetius’ teaching in Athens.

Now, in a supremely erudite investigation of his influence extending beyond the 27 fragments attributed to him, a third silhouette has been cut out with as much distinctiveness as the sources allow for Hecato of Rhodes, also a disciple of Panaetius, also working in Rhodes. V. presents Hecato as a Stoic who exemplifies this intermediary status: sincerely loyal to the founding fathers, whilst also developing reflections that lead to innovations both conceptual and methodological in the field of ethics. He is a source for Cicero's On Duties (Book 3) in which the Hecatonian practice of testing theory on case studies, the ancestor of thought experiments, is instituted as a philosophical tool; as also of Seneca's On Benefits, cited if only to be criticised, thereby validating the priority of certain Hecatonian questions (pp. 326–7). Is Hecato for all that very important, and has history done an injustice to him and us by depriving us of his works? The honest answer, which V. herself concedes, is: not quite. But one of the qualities of the book is to argue that history of philosophy in general, and the development and consolidation of Stoicism in particular, is not exclusively made by the important figures, even if the history of the school is spearheaded by them. For the greatness of Chrysippus to have been not only kept alive throughout the history of the school, but also understood by generations of Stoics and their students, it was necessary to re-explain his claims. Thus, Hecato's fragment 7 on virtue (D.L. 7.125–6) takes Chrysippus’ side in a debate against Zeno on the status of the plurality of the virtues. They are not different names for one and the same unique virtue, but for Chrysippus, followed by Hecato, each different virtue has its independence in as much as it is an individualisable quality. The basis for Chrysippus’ position, as V. explains, is Chrysippus’ elaboration of the notion of ‘common theorems’, which elicits a hierarchy of levels by which a common level governs a subordinate level of individualised theorems (pp. 253–5). In a chapter entitled ‘Rethinking Virtue’ this hierarchy of the virtues is further linked to the Chrysippean notion of principal and auxiliary causes (pp. 258–61). Enter Hecato: V. proposes to infer that a reflection on the parallel between subordinate theorems and the auxiliary status of the particular virtues elucidates his contribution, from fragment 6 (from D.L. 7.90), in which Hecato distinguishes the virtues derived from theorems from those that are ‘a-theoretical’, and ‘extensions of theoretical virtues’, such as health. To understand the Hecatonian a-theoretical virtue, it is thus necessary to retrace the conceptual and historical genealogy, which shows how Hecato places himself in a direct lineage with regard to his predecessors all the better to innovate by following through the original Chrysippean commitment to the logical and physical basis of the analysis of virtues as qualities, hence bodies, which cause another body, the soul of the person they qualify, to be and act according to a specific way (courageous, magnanimous etc.). Since then, the state of the person is itself an exemplification of the virtue that causes it to be the way it is, health itself must be a direct expression of the virtue in the soul – hence itself by extension a virtue, however a-theoretical.

The book has a triadic configuration. A preliminary examination of the historical and philological editions of Hecato since the nineteenth century compares the choices made with the kind of Hecato thus portrayed, from Cynical tendencies noted in the first editions to a more Epicurean portrait given by Pierre Grimal, who makes a case for Hecato's promotion of tranquillity, which, as V. shows later (pp. 278–80), belongs to an already Panaetian appropriation and which, for the Stoic, is more akin to constancy than the ataraxic ideal of the Epicureans. A thorough and erudite investigation into the rationale of the choice of fragments constitutes the main block of this part, in which the character and ideologies of the different sources are weighed up against the relevance of the fragments and the revelations they yield. All in all, the verdict is that Hecato is more present than earlier editors would concede in the Roman reception of Greek Stoicism. Then comes V.'s edition of the fragments with a French translation, followed by precious textual and philological notes for each fragment. The last part, which could constitute a book in its own right, is an assessment of the contribution of Hecato to Stoic ethics. It places Hecato within the larger philosophical debate, showing how his ideas on the virtues, on magnanimity, on the scaling of benefits with regard to friendship, on the use of provocative maxims are the fruit of rich and diverse discussions not only within his school but also incorporating Aristotelian perspectives, Plato's Protagoras and Democritean ideals of the good life.

The book's erudition plays thus on two levels: first, within the subtle and at times disconcertingly minute distinctions in interpretation of one and the same Stoic concept, which evolves from Chrysippus via Panaetius via Seneca back to Hecato. Secondly, within the broader network of appropriations, rejections and counter-interpretations of the debate between the schools of antiquity, which renders the period of Middle, or ‘late Middle’, Stoicism so fascinating and so elusive. If the first level makes this book of particular interest to specialists of the history of Stoicism, the second level opens the readership to those interested in the post-Hellenistic pre-Roman cultural ebullition who can go straight to the third part of the book.