Though it might seem that Platonism is just what we find in the dialogues, the relationship between the philosopher Plato and the philosophical position or system known as Platonism is in fact far from obvious. The problem is this: whether and to what extent the philosophy in the dialogues is accurately represented in any of the conflicting accounts of self-declared followers of Plato over a period of a millennium and more. The matter is no doubt complicated by the disparate and even irreconcilable accounts, although it is all too easy to emphasize the disagreements and neglect the underlying shared assumptions. For these reasons, a concise, comprehensive, learned, and mostly non-polemical monograph describing Platonism from the perspectives of the Platonists themselves is to be warmly welcomed. That is what Mauro Bonazzi has delivered.
The book is divided into four chapters, following the standard division of the 'phases' of the history of Platonism: the Old Academy, the New or 'Sceptical' Academy, Middle Platonism, and Neoplatonism. There are two substantial appendices, one dealing with Platonism and politics (both Greek and Roman) and one dealing with the vexed topic of Christian Platonism.
The first section (3-37) addresses the absolutely crucial question of how the first generation of Academics understood Plato. It should be noted in passing that Bonazzi, to his credit, does not attempt to adjudicate among various 'readings' of Plato on the basis of an imaginary and privileged twenty-first century non-historical criterion of accuracy. That is, he does not purport to judge Aristotle, Speusippus, and Xenocrates on the assumption that some modern day understanding of Plato sets the standard of correctness. Rather, he closely follows the conflicting evidence and reaches the not unreasonable conclusion that interpretations of Plato, especially those of Speusippus and Xenocrates, seem to be advanced more as alterations to Plato's doctrines made in response to Aristotle's criticisms than as attempts to accurately represent the contents of the dialogues (25).
But this eirenic position must confront the serious possibility that Plato's philosophy is not just the sum of the various claims made in the dialogues. That is, it must face the considerable evidence that Plato had unwritten doctrines. For ultimately the answer to the question of how Platonism is related to Plato's philosophy must be built on the foundation of how that philosophy was understood by the first generation. If their assumption was that the philosophy is contained solely in the dialogues, then subsequent Platonists have no good grounds for going outside the dialogues for their construction of Platonism. By contrast, if Platonism was from the start understood as Plato's philosophy as transmitted to the Old Academy, but only partially or obscurely represented in the dialogues, then all of later Platonism cannot be dismissed just because what is said does not have proof text in the dialogues.
One example must here suffice. Aristotle tells us that Plato identified the Idea of the Good with the One which, along with the Indefinite Dyad, are the principles of Forms, which themselves are Numbers. Middle Platonists appear generally to ignore or to be unaware of this testimony. As a result, what is most distinctive about Middle Platonic interpretations of Plato is the identification of the first ontological principle of all with the Demiurge and the making of the Forms as thoughts in the Demiurge's mind. By contrast, Neoplatonists, beginning with Plotinus, took Aristotle's testimony as evidently accurate and consequently identified the first principle of all with the One that is otherwise known as the Good, finding this principle in the first hypothesis of the second part of the dialogue Parmenides. Bonazzi sets forth with admirable clarity the main differences between Middle Platonists and Neoplatonists, but though he acknowledges the evidence for Plato's unwritten doctrines and, accordingly, the accuracy or at least relevance of Aristotle's testimony, he eschews any interest in pursuing the matter further. But this is in effect to undercut any effort to connect Plato and Platonism (see 13, n.32).
The second section of the book (38-72) is focused on the so-called New Academy. The evidence regarding the New Academy of Arcesilaus and Carneades presents its own challenges to the reconstruction of Platonism and its relation to Plato. Undoubtedly, the ancients had no difficulty finding evidence in the dialogues of what we might term a sceptical tendency in Plato, particularly if we focus on the so-called Socratic dialogues. Bonazzi has little to say on the Socratic question and how later Platonists treated a putative Socratic philosophy in the dialogues. He seems to assume, however, that Socrates' disavowal of knowledge and the tentative nature of a number of the dialogues justify a sceptical position to be considered an authentic development of Platonism (62). Oddly, Bonazzi offers as a reason for denying a break between Plato and scepticism the assertion that Plato himself never claimed to possess incontrovertible knowledge. He does not ask whether, even if this were true, it has any relevance for Plato's doctrine on the nature of knowledge. Nor does he consider that nowhere does Plato acknowledge the possibility of knowledge or epistēmē that is anything but incontrovertible or infallible. Indeed, Bonazzi makes the unsupported and, in my view, unsupportable claim that the 'fallibilism' of Philo of Larissa has a 'strong affinity' with that of Plato. There seems to me to be no evidence for this in the dialogues, a fact that is not at all in tension with the claim that the dialogues are not intended to be systematic statements of doctrine. Incidentally, Bonazzi here seems to let drop his guarded neutral stance regarding the unwritten doctrines, for if these are anything near to a central feature of Platonism, this cannot but affect how we look at the dialogues. Accordingly, if the New Academic attacks on Stoicism are an attack on the possibility of incontrovertible knowledge—something the Stoics unwaveringly insisted on—they are also an attack on Platonism, a conclusion that would add to the puzzle of New Academic Platonic provenance. Bonazzi's attempt to play down the divide between scepticism and Platonism is not, in my view, enhanced by his claim that Plato's teaching is primarily methodological (63). If this were indeed the case, one would be forced to conclude that virtually all Platonists have misunderstood Plato. For apart from an obligatory and obvious appeal to dialectic taken from the dialogues, and some rather desultory attempts to adapt Aristotelian syllogistic to Platonic themes, methodology is very much in the background for Middle and Neo Platonists. I here leave aside the methodology for the study of Plato's philosophy, in particular the reading order of the dialogues, something that actually grew steadily in importance over time.
Bonazzi's third section (73-109) on Middle Platonism, 'Verso il sistema', is a concise introduction to this vastly complicated and frustratingly lacunose material. Bonazzi himself has written widely on the Middle Platonists. His view that philosophers in the period between Antiochus of Ascalon and Numenius are in some sense focused on the systematization of Plato is a well established conclusion among scholars. In addition, it is also generally agreed that for some Middle Platonists the systematization of Plato required or at least opened up the possibility of integrating Stoic insights into a Platonic construct. Bonazzi does not, however, lay much stress on the differences between the Pythagorizing and the Stoicizing Platonists, the former perhaps having more of a claim to be accurately representing Plato than the latter.
Bonazzi rightly emphasizes the importance of Plato's Timaeus for the Middle Platonists, ably articulating the crucial move made by them to use that dialogue to controvert the Republic by identifying the Demiurge with the first principle of all. Forms, then, either become divine thoughts or eternal divine principles anterior to the Demiurge himself (92-93). Evident here is a transition from (a) a view of Platonism that takes the dialogues as one partial expression of the systematic philosophical whole to (b) an emphasis entirely on the dialogues to the exclusion of the unwritten teachings to (c) an emphasis on one dialogue as revelatory of Platonism. It is hardly surprising that if one is going to opt for (c), Timaeus is perhaps the inevitable choice. Bonazzi has rich and lucid sections on the controversies among Middle Platonists concerning the eternity of the world, the nature of knowledge, and the problem of free will and determinism. I found particularly illuminating his remarks on the Middle Platonic introduction of philosophy into imperial Roman paideia (108-09). It is no doubt owing to the introduction of Platonism into the educational system of the elite that philosophy from the 3rd century onward is almost entirely Platonic.
The final section of the book (110-60) is elegantly compact in its presentation of the more than 300 years of complex and often obscure philosophy of the so-called Neoplatonists. The presentation is perhaps a bit too compact for the non-specialist. Bonazzi tries to cover both the historical filiations of the Roman, Athenian, and Alexandrian 'schools' and at the same time provide a survey of the central problems treated in the vast extant mass of material along with the most important variations in doctrine. The treatments of Porphyry, Iamblichus, and especially, Proclus and Damascius are, inevitably, very brief.
Bonazzi acknowledges that the Neoplatonists saw themselves as 'exegetes' of Plato, eschewing any claim to originality. He does not acknowledge that this claim, seemingly preposterous to many, rests entirely on the assumption that Platonism is not the sum of the dialogues’ contents, indeed, that it is a philosophy that at its core transcends and even antedates Plato himself. This is not just a point about Platonism in relation to Plato. It is a point about the nature of the exegetical and personal works of philosophers from Plotinus to Damascius. Even in their exegesis of the dialogues, the goal was to get to the essence of the system behind them. And the assumption that there was indeed such a system was not simply a function of their acceptance of the veracity of Aristotle's testimony and the oral tradition, but rather based on an argument about the philosophical principles behind all of the written and unwritten arguments of Plato. That is, only a systematic metaphysics could ultimately justify the many controversial assertions that almost everyone agrees Plato makes in the dialogues. Bonazzi is right in maintaining (125) that Plotinus' philosophy is a 'watershed' in the history of Platonism. This is so, however, not because of his originality but because of his powerful articulation of the Platonic system, something Bonazzi does eventually mention (159). Unless one discounts the Aristotelian evidence, Plotinus' identification of the Good with the One is not, as Bonazzi says, 'a new variation' on the theme of a first principle of all.
Bonazzi concludes by saying (159-60) that the history of the philosophical writings of the self-declared Platonists suggests to us that there is not a single Platonism but a number of 'Platonisms'. Perhaps this is not so far from what I take to be the correct position, namely, that there is a single set of Platonic principles, but that there are many variations in their application since these principles are underdetermining for the solution to many if not most philosophical problems.
Bonazzi's book is to be warmly recommended to anyone wishing to expand his or her horizons in ancient philosophy. The book also includes a fairly comprehensive bibliography for further study. It would be a considerable service to the field if someone were to take up the self-effacing task of translating this book into English.