The present book, In Search of the Ideas. Platonism and Hellenistic Philosophy from Antiochus to Plotinus,1 is a history of Platonic philosophy in four rich but often neglected centuries of philosophy, running from the 1st century BCE to the 3rd century CE. What distinguishes this book from other histories of the reception of Plato is that Bonazzi switches the main focus of his research to epistemology (the doctrine of ideas and, more generally, the study of the nature of human knowledge), while others have concentrated mostly on cosmology and ontology. In his previous works, Bonazzi analyzed skeptical tendencies in Platonism, seeing skepticism both as the cause of the ‘crisis of Platonism’ during these centuries, and as the basis for finding a common identity among all these thinkers who traced their philosophical roots back to Plato’s philosophy.2 In the present work, Bonazzi looks at the relationship between Platonism and Stoicism. Looking at the epistemological positions of these philosophers provides a way to grasp the various and complex issues involved in the dispute between the Platonists and Hellenistic philosophies, chiefly Stoicism.
His account must first wrestle with the appellation “Platonist.” In fact, much scholarly debate surrounds the history of Platonic philosophy in general, and in particular the Platonism(s) of the period situated between the revival of the “Old” Academy by Antiochus, through the so-called Middle Platonists (for example, Plutarch, the anonymous commentator on the Theaetetus, Alcinous, Apuleius, Numenius), up to Plotinus. This is due in large part to a change or shift in the nomenclature of Platonic philosophers, which had also institutional implications, because most of them (Dörrie and Baltes listed around 170 philosophers), from around the 1st century BCE onwards, called themselves “Platonikoi” or “Platonici”, instead of the common name “Akademaikoi”. Much ink has been spilled over the implications of this shift in appellation. And for a good reason: What did it really mean to be a “Platonist” in the last century BCE and the first three centuries CE?
According to Bonazzi, Platonism had entered a time of identity-crisis during the 1st century BCE, a crisis precipitated by the triumph of skepticism in the Academy. Furthermore, the crisis was not only institutional, but also doctrinal, since the other philosophical schools were trying to appropriate the doctrines of Plato. “Prendre le contrôle de Platon signifiera prendre le contrôle de la philosophie” (p. 19). Thus, the Platonists’ ambition was to show that, correctly understood, the philosophy of Plato could resolve problems that the other schools could not. In the first chapter (pp. 15-68), Bonazzi details how Antiochus tried to remedy to this situation by showing that the Stoics and the Platonists defended the same doctrines and belonged to the same philosophical tradition (p. 24). Hence, Antiochus wanted to appropriate Stoicism, to integrate it into the Platonic system. He tried to do this by identifying the Platonic Ideas with the Stoic ennoiai (p. 31), showing a structural affinity between both theories (p. 34). As explained by Bonazzi, “les ennoiai sont le point de départ qui nous permet d’accéder à la connaissance de l’objet que l’on recherche; et, si cela est possible, c’est grâce au fait que les ennoiai sont ce qui reste dans l’intellect humain de la vision prénatale des Idées (c’est-à-dire, la réminiscence)” (p. 44).
The second chapter (pp. 69-115) is mainly dedicated to Plutarch and to the anonymous commentary on Plato’s Theaetetus, and ends with a discussion of Alcinous. In this chapter, Bonazzi looks at the epistemological consequences of two fundamental tenets of Platonism, to wit, the transcendence of the intelligible and divine Principles (God and the Ideas or Forms) and the dualism between the sensible world and the intelligible. In order to avoid the philosophical problems of skepticism, Plutarch adopts a dualist ontology and epistemology, according to which there is an intelligible, and so stable, world beyond the empirical, unstable reality of everyday life. The Epicureans, for example (still according to Plutarch) are merely empiricists, that is, they consider as real only the sensible and material world. This attitude leads unequivocally towards radical skepticism. According to Plutarch, the notion of “metaphysical skepticism” is the common denominator of Arcesilaus’ (and of Plutarch’s) anti-empiricism and dualism. This sort of skepticism has almost nothing to do with Pyrrhonist skepticism, and allows thus Plutarch to include Arcesilaus in the Platonic tradition. Furthermore, the Commentarium in Platonis “Theaetetum”, a papyrus found in 1901 in Egypt, and dated to the first half of the first century CE, or the middle of the first century BCE (the date is still a controversial question), shows how a Middle Platonist could integrate the skepticism of the New Academy within a unitary view of the history of Platonism.
The third and last chapter (pp. 117-51) deals with Plotinus and his polemic against skepticism. Starting with a discussion of Ennead V 5  (“That the Intellectual Beings are not Outside the Intellect, and on the Good”), Bonazzi discusses the hypothesis according to which Plotinus constructed his dogmatism through his confrontation with skepticism. He argues, on the contrary, Plotinus never considered skepticism as a menace to knowledge. Thus, Bonazzi thinks that Plotinus, in his treatise, is arguing against not only Cassius Longinus, one of the first teachers of Porphyry, but also against all Platonists who distinguished between the Intellect and the Ideas. In Treatise 32, Plotinus affirms the cognitive identity between the Intellect and the Intelligibles, that is, between the intellect and its objects. Therefore, according to Plotinus, those who do not accept the identity between the intellect and the Intelligibles fall into skepticism – like the empiricists, who maintain a firm distinction between the knowing subject and the object of knowledge. Moreover, Plotinus tried to rethink Platonism from a critical confrontation with Aristotle (p. 148).
Perhaps because of the difficulty of the subject, due in part to the scarcity of our sources, we are not told what this ‘new’ Platonic identity consists in. For example, were there something like building blocks (Bausteine) or common doctrines held by particular Platonists from the first century BCE onwards?3 We know that despite various and fundamental doctrinal differences (I think especially of the debate between Iamblichus and Porphyry / Plotinus), the Neoplatonists, from Plotinus to Simplicius, identified themselves as belonging to a specific school of thought because they shared some basic common beliefs, aims and worldview. But what about the “Platonists” analyzed in this book?
Through his subtle analyses, Bonazzi does show the intense and creative power of various Platonists who distinguished themselves from all the other Hellenistic philosophies to assert a specific identity. But though specific, this identity was not adopted by most later Platonists. As far as their epistemologies were concerned, neither Antiochus nor Plotinus had many followers.
Following Bonazzi’s claims, perhaps all we can really ascertain is that, notwithstanding their differences, all the Platonists of the period under discussion accepted the Platonic dialogues as the main source of their philosophies. And it is because of their high regard of Plato’s writings, in which one can find support for two contradictory opinions, that the Platonists differed in so many ways. The best solution may consist in acknowledging the constitutive ambiguity of Plato himself (p. 150).
1. I think it is interesting to note the similarities (and differences) between Bonazzi’s project, and title, and Jan Opsomer’s In Search of the Truth. Academic Tendencies in Middle Platonism (Brussels: KAWLSK, 1998): BMCR 2003.08.19.
2. See Bonazzi’s PhD Dissertation on the debate in the Platonic circles around the skeptical interpretation of Plato, published as Academici e Platonici. Il dibattito antico sullo scetticismo di Platone (Milan: Led, 2003).
3. See H. Dörrie’s introduction to the monumental 8 volumes (4 more are in preparation) of Der Platonismus in der Antike. Grundlagen – System – Entwicklung (Stuttgart-Bad Cannstatt: Frommann-Holzboog, 1987-2008).