(Note: this post has been significantly revised. See note (*) below.)
I begin now a series of posts on the recent book by Lloyd Gerson, Aristotle and Other Platonists, which intrigued me because of its talk of investigating the 'harmony' between Plato and Aristotle.
I find the promise of a 'harmony' intriguing for two reasons, because: (1) this would match my idea of what philosophical progress amounts to, and (2) a 'harmony' might indicate whether there was such a thing as a 'perennial philosophy'. Let me explain.
(1) I accept Aristotle's view about philosophical progess: Z is a better philosophical view than X and Y, if Z incorporates whatever we regard as interesting and true in X and Y, and Z furthermore can give an account of those ways in which X and Y, in comparison with Z, got things wrong. In sum: a better philosophical view is a bigger truth, which shows by its synthetic nature that it is bigger, and which accounts for why lesser truths went wrong where they did.
When I hear talk of a 'harmony of Plato and Aristotle', then, I expect that this would be a view that was better than Plato's or Aristotle's taken separately; it would mark progress in philosophy.
(2) It seems to me that if there is knowledge (i.e. contact with the truth) anywhere in philosophy, this would show itself in the existence of a school of thought which over time showed a certain kind of vitality and development, not unlike that of a living system. Because of the nature of philosophy (in philosophy a mistake is a kind of 'folly' rather than an 'error' or 'ignorance'), I do not expect that near universal agreement among intelligent and informed persons will be a mark of philosophical truth, as it is in the natural sciences. I expect, rather, that the mark of knowledge will be a vitality of the sort I have mentioned. (To see examples of how this notion of 'vitality' may be explicated, see Alasdair MacIntrye's Three Rival Versions of Moral Inquiry, or, as an analogue in the area of theology, John Henry Newman's Essay on the Development of Christian Doctrine.)
I have wondered, then, if the 'harmonization' which Gerson will investigate is a system with precisely this kind of enduring vitality, and which thus might count as a philosophia perennis.
Now I must say that, at first glance, I have serious doubts that these hopes will be fulfilled. I have not entirely ruled it out that they will, but Gerson's remarks in his Introduction are not encouraging.
The problem is already indicated in the title of the book, Aristotle and Other Platonists. The title is meant to be provocative, to be sure, yet it itself suggests that the 'harmony' between Aristotle and Plato to be achieved, is not that of arriving at a bigger view, of the sort I have described, but rather at some kind of reduction of Aristotle to Plato.
And then Gerson says just as much in the Introduction. He says that by a 'harmony' he means that, when Aristotle seems to disagree with Plato, either the disagreement is verbal merely (that is, a case of people using different language to say the same thing), or these views of Aristotle:
... are different from those of Plato because they rest on an imperfect or incomplete grasp by Aristotle of the correct Platonic principles (5).That is, the harmonization amounts to: Plato is correct and Aristotle either agrees with Plato or disagrees because of a misunderstanding.
Now this would not be a 'harmony' at all but, as I said, as reduction of Aristotle to Plato--an attempt to vindicate the truth of Platonism as against apparent criticisms from Aristotle. As such, the work that Gerson is exploring would fall within a common, but to my mind not respectable, genre of philosophy--viz. 'school advocacy', not unlike works by Thomists who argued that Kant and Aquinas are saying the same thing (and when Kant seems to differ, that is because he misunderstands the correct Thomistic principle); or Wittgensteinians who argue that Aristotle and Wittgenstein are saying the same thing; etc. etc. But in this case the 'school' that was doing the advocating ('neoplatonism') would not be a thriving movement today but rather--it might be thought-- a strange interlude in the history of philosophy from the distant past.
Apparently sensing that the arguments he will be exploring are vulnerable to such a criticism, Gerson writes:
...a book that aimed to do nothing more than show that a group of largely forgotten scholars and eccentric philosophers were not quite as naive as is sometimes thought would in my view be of little interest. Rather, I want to show that reading Aristotle as a Platonist, or understanding Aristotelianism as a type of Platonism, far from being an exercise in historical perversity, does actually yield significant results both exegetical and philosophical (7).Well, those are the stakes, are they not? That is, if Gerson cannot show that there are 'significant results' from his efforts, then, as he admits, his book is no more than "an exercise in historical perversity". To my mind, then, that becomes the guiding question as I read his book: Does Gerson follow through with his promise of 'significant results'?
(*) It was pointed out to me that my original post was supposing too much, in attributing to Lloyd Gerson as well the advocacy and view of harmonization that he is investigating in certain neo-platonists. I have revised the post to remove this suggestion, and I regret that unnecessary imputation, arising from my misreading of Gerson's Introduction.