The volume under review brings together 10 papers originally presented at the European Science Foundation Exploratory Workshop at Castelvecchio in June 2006. ‘Exploratory’ is quite the right word: the subject of the collection, Neoplatonic philosophy of nature, is underexplored to this day, and only now beginning to attract the attention it deserves. The papers collected here range from Xenarchus, who makes a brief appearance in Rashed’s piece, to Proclus, with Plotinus and Proclus featuring most prominently.
In their ‘Introduction’, Riccardo Chiaradonna and Franco Trabattoni provide a broader context for the individual papers, focusing on two questions in particular: (1) did Neoplatonic philosophers ever succeed in giving a ‘coherent overall description of physical reality’ (13)? (Answer: mostly so, and metaphysics helped them); and (2) did they manage to account for natural phenomena in all their complexity? (Answer: not really, because they rarely moved beyond generalities.)
The first essay in the collection, by Marwan Rashed, reconstructs why three different thinkers, namely Xenarchus, Ptolemy and Plotinus, embraced the idea that the motion of elements is not necessarily rectilinear (‘Contre le movement rectiligne naturel: Trois adversaires (Xénarque, Ptolemée, Plotin) pour une thèse’). While Simplicius, in his commentary On the Heavens, lumps the three together in their opposition to Aristotle, Rashed can offer a nuanced picture of what motivated their doctrines.
In his study on the traces of Galen’s treatise On Demonstration in Neoplatonic writers such as Themistius, Simplicius, Nemesius of Emesa and John Philoponus, Riccardo Chiaradonna (‘Le traité de Galien Sur la Démonstration et sa posterité tardo-antique’) argues that Galen’s lack of interest in ontology places him firmly in the final phase of Hellenistic philosophy, which thinkers with rather different priorities, such as Alexander of Aphrodisias and Plotinus, brought to a close.
George Karamanolis (‘Plotinus on quality and immanent form’) finds an original doctrine of quality in Plotinus, particularly in Enn. II.6 and VI.1-3. He distinguishes between a ‘wide’ sense of quality in Plotinus, in which all sensible features are qualities, and a ‘narrow’ sense, in which only accidental features are qualities, but not immanent forms, since the latter account for something’s being like a real substance or transcendent forming principle ( logos).
Our knowledge of the natural world comes into focus in Robbert M. van den Berg’s contribution (‘As we are always speaking of them and using their names on every occasion. Plotinus, Enn. III.7 : Language, experience and the philosophy of time in Neoplatonism’). He argues that Plotinus, and after him Augustine and Proclus, distinguished two kinds of ‘common notions’, one based on our perceptions of natural phenomena, one drawn from intuitions of metaphysical reality. Neither Plotinus nor Proclus have much time for the former kind; still, they admit that it can be a useful starting-point of inquiry and should ideally be accommodated by good theorizing.
Plotinus’ treatise on nature and contemplation, the subject of Christian Wildberg’s fine piece in this volume (‘A world of thoughts: Plotinus on nature and contemplation ( Enn. III.8  1-6)’), must be one of the high points of Neoplatonic thinking about the natural world. Wildberg’s analysis succeeds brilliantly in making a strange thought, that all of nature contemplates the reality prior to it, somewhat less strange, and is one of the real gems in this collection.
Chiara Russi (‘Causality and sensible objects: A comparison between Plotinus and Proclus’) examines the different theories of causality in Plotinus and Proclus. She finds that, while Proclus makes use of a duality of principles (limit and unlimited), Plotinus accounts for the generation of lower living things with reference to a single psychic principle.
Alessandro Linguiti (‘Physis as Heimarmene: On some fundamental principles of the Neoplatonic philosophy of nature’) examines the relation between Nature and Fate in Proclus’ philosophy, drawing mainly on texts from De Providentia, but with excursions into the Platonic Theology and the Timaeus Commentary. In De Providentia, Fate means much the same as natural necessity; elsewhere, it emerges as Nature qualified by the divine.
The harmonization of Plato’s and Aristotle’s accounts of motion in Proclus’ works is the subject of Jan Opsomer’s insightful and wide-ranging paper (‘The integration of Aristotelian physics in a Neoplatonic context: Proclus on movers and divisibility’). By superimposing Platonic spiritual motion onto an Aristotelian account of physical motion, Proclus constructs a theory that is not without difficulties, especially when it comes to using Aristotelian concepts to explain incorporeal processes, as Opsomer shows with great clarity.
In Plato’s Timaeus, cosmic order is the product of an intelligent cause prevailing over a disordered substrate. Gerd van Riel (‘Proclus on matter and physical necessity’) takes the reader through the transformation of this basic doctrine in Proclus, who turns it into a slightly bewildering multi-stage account. Van Riel very helpfully represents this theory in a scheme at the end of his article.
Finally, Carlos Steel (‘The divine Earth: Proclus on Timaeus 40bc’) outlines Proclus’ defense of the earth’s divinity, which manifests itself in number of different ways, for instance through its nature as divine living being, its motion and its role as a guardian and nurse. Steel is very good at pointing out how Proclus defends his reading of the central Timaeus passage with references to the Phaedo ’s myth of the true earth. His paper fittingly culminates in a list of the divine properties of the earth, drawn up in accordance with the Platonic Theology.
In sum, we have here an altogether fine collection of essays. It comes with a bibliography, and indexes of ancient and modern authors, and of passages cited.
One final remark: the scope of the papers is perhaps more restricted than its title, which promises to consider physics and philosophy of nature in ‘Neoplatonism’ quite generally, might suggest. There is, on the whole, little discussion of the ancient commentators on Aristotle, who, one would think, had interesting things to say about these subjects too. This reviewer, at any rate, would very much like to see a companion volume with similarly excellent contributions, only this time more focused on the second head of the beast, viz. the Aristotelian commentary tradition.