This text is an exhaustive study of the sources at our disposal for reconstructing Xenarchus of Seleucia's philosophy. The volume provides a complete picture of his work and a contextualisation of the peculiar reception of Aristotelian philosophy in the first century b.c.e. F. had already made an important contribution to this field in Aristotle and the Science of Nature: Unity without Uniformity (2005). This new book carries forward the investigation he started there.
Xenarchus was one of the earliest interpreters of Aristotle and he gave impetus to the revival of interest in his philosophy that took place in the first century b.c.e. In this context, F. reminds us that Xenarchus is often presented as a vigorous critic of Aristotle, thanks in part to the peculiar transmission of his arguments against the theory of the fifth substance (i.e. the aither) effected by Alexander. F. shows throughout the book that there is more to his philosophy than that.
F. presents Xenarchus as a creative philosopher and suggests that his commentaries are best understood as an attempt to revise and update Aristotle's thought. Xenarchus offers, for example, a creative interpretation of his theory of motion, according to which the celestial body is expandable; he also introduces new insights on the question of the prôton oikeion of human beings. One of the most important contributions of this book is F.'s effort to situate the figure of Xenarchus as a ‘counterexample’ to any monolithic account of the origins of philosophical exegesis and the transmission of Aristotelian philosophy.
Concerning the role of Xenarchus' thought in the history of Philosophy, F.'s interpretation is at a certain remove from that of P. Moraux (Der Aristotelismus bei den Griechen, vol. 1 [1973], pp. xii–xx). On the one hand, F. affirms that there is slim but clear evidence that his interests were not limited to physics, but that he was also concerned with ethics and psychology; on the other, he finds in Xenarchus both elements of rupture and strands of continuity regarding Aristotelian philosophy. Both aspects of his philosophy are relevant if we wish to reconstruct the complete picture of Xenarchus' philosophy. In this way, F. shares with M. Rashed the idea that one of the best ways to understand Xenarchus' thought is as a simplification of Aristotle's philosophy (M. Rashed: ‘Contre le mouvement rectiligne naturel: trois adversaries [Xenarque, Ptolémée, Plotin] pour une these’, in R. Chiaradonna and F. Trabattoni [edd.], Physics and Philosophy of Nature in Greek Neoplatonism [2009], pp. 18–19).
The book is divided into three parts, plus an introduction and a conclusion. Part 1 examines the historical context and philosophical significance of Xenarchus' works. F. presents Strabo's testimony, according to which Xenarchus was born in Seleucia and spent most of his life teaching in Alexandria, Athens and Rome. He discusses the connections between the philosopher and some public figures of his time and the relations he had with them. The second issue in this first part is Xenarchus' affiliation. The sources describe him as a Peripatetic philosopher; but, as F. notes, what that means is not immediately evident. What is certain is that he was not a Peripatetic in the sense of being a member of the school founded by Aristotle in Athens, since the Lyceum had already ceased to exist as an institution. However, the Aristotelian school continued in existence as a kind of sect; Xenarchus could thus be termed a Peripatetic in this latter sense. F. explains the nature of his participation in this Aristotelian tradition, sharing points of view with other Peripatetics like Theophrastus and Strato (e.g. regarding the nature of the heavens) and with Aristotle himself (on psychological or ethical doctrines).
The first part of the book aims to situate Xenarchus' activity within the context of the return to Aristotle that took place in the first century b.c.e. Aristotle's writings enjoyed limited circulation in the Hellenistic period, but the situation changed from the beginning of the first century. It is not easy to explain the change of attitude towards Aristotle (and also Plato), but it is clear that it cannot be attributed to any single cause. F. points out some factors, for example the edition of Aristotle's works made by Andronicus, the collapse of the Athenian Schools, the decentralisation of philosophy, the intense exegetical activity on foundational works (Timaeus and Categories) and the interest in the construction of a philosophical system conciliating Plato and Aristotle. All of these issues are part of a complex picture that does not facilitate a simple answer. F. explores each these factors and demonstrates the complexity of the matter, while avoiding any kind of anachronism in the analysis.
Part 2 gathers the extant evidence concerning Xenarchus' life and work with a compilation of the relevant Greek texts with English translations and a set of explanatory notes. Although F. does not attempt a new critical edition of these texts, he does indicate in the footnotes where important textual variants exist in a particular tradition. In order to help understand Xenarchus' objections to the fifth substance, he also includes a translation of Aristotle's arguments for the existence of a celestial simple body in addition to the four sublunary elements. After that, he presents the testimonies concerning Xenarchus, divided into five sections: (1) life, (2) physics, (3) psychology, (4) ethics and (5) passages on the Timaeus. The principal references are: for the first group of texts, Strabo; for the second Julian the Apostate, but even more Simplicius' commentary on De Caelo; for psychology Aëtius (as reported by Stobaeus) and Philoponus; regarding ethics, the Mantissa of Alexander is the principal source and the testimony appears in the context of a discussion of the ‘first appropriate thing’ (prôton oikeion). Finally, the commentary of Proclus on the Timaeus is the source for Xenarchus' opinion about that book. The translation that F. offers is extremely accurate and the notes are pertinent. He concentrates his attention on helping the reader to work through and understand Xenarchus' text. His expositions are supplemented by lucid analyses of the structure of particular passages, and by careful reminders of how individual points of detail relate to the broader structure of Xenarchus' arguments. This work is a very important contribution to reconstructing the complexity of philosophical dialogue in first-century b.c.e. Aristotelianism.
The analysis of the extant evidence is followed by three short essays in Part 3. In the first essay, ‘Xenarchus and the Reception of Aristotle's Physics in Antiquity’, F. sets out to demonstrate that the novelty and audacity of Aristotle's Physics are fully revealed by investigating the often mixed reception of this physics in the early stages of the Peripatetic tradition. The second essay, ‘Xenarchus and Plotinus’, deals with the reception of Xenarchus' revision of Aristotle's doctrine of natural motion. This enjoyed considerable success in Late Antiquity, providing the conceptual resources for incorporating the Aristotelian notions of natural place and natural motion into a conception of the sensible world informed by Plato's Timaeus, while at the same time dispensing with Aristotle's thesis that the heavens are made of a special simple body. The third essay, ‘Vestiges of Xenarchus in the Middle Ages’, considers the subsequent reception of Xenarchus' objections to the doctrine of the fifth substance. These essays are just a sample of the potential fecundity of the study of Xenarchus as an important step in the history of Aristotelianism and the philosophy of nature.
In the conclusion F. returns to the question of Xenarchus' place in the Peripatetic tradition and the nature of his Aristotelianism. Throughout the book – but especially in the final part – F. emphasises that Xenarchus only becomes an anomaly within the Peripatetic tradition if we identify exegesis with orthodoxy or if we consider the post-Hellenistic return to Aristotle as a straightforward reinstatement of Aristotle's philosophy culminating in Alexander of Aphrodisias. The textual evidence about Xenarchus' thought is hard to reconcile with this exegetical horizon. In contrast, Xenarchus can be seen as a philosopher vigorously engaged with Aristotle, despite the rejection of certain doctrines of the master. He would thus appear as a ‘counterexample’ to monolithic accounts of the history of the Aristotelian transmission.
