Was Plato a Platonist? A cheeky question, perhaps. If by “Platonist” we mean “a follower of Plato,” then the question is entirely captious. Plato was no more a Platonist than Jesus was a Christian. The question is only marginally more illuminating if we take it to mean “Would Plato have agreed with one or another of the historical, systematic representations of his philosophy?” Naturally, this question, like all questions about counterfactuals in the history of philosophy, is unanswerable. But if the question means “Do we possess evidence that supports the view that Plato’s own philosophy was in substantial agreement with that of one or another soi-disant Platonists?” then, according to many scholars, we are in a relatively good position to give a definite answer to the question. And the answer is unequivocally no, Plato was not a Platonist. In this book, I present the case that the correct answer is more likely to be yes.
The term ‘Platonism’ is used today in roughly three ways. One of these refers to a philosophical position in the philosophy of mathematics and in contemporary metaphysics that is only loosely connected with any historical philosophical view.1 This use of the term I will mostly leave aside. The term ‘Platonism’ is, second, also used to refer loosely to whatever is found in Plato’s dialogues. It is important, as I will explain in a moment, that those who use the term in this way both mean to refer exclusively to the dialogues and do not necessarily make the claim that ‘Platonism’ used in this way refers to one consistent philosophical position. Thus, ‘Platonism’ is the label for whatever Plato said or can be gleaned to have meant through the use of his literary characters—Socrates and the rest. Those who use the term ‘Platonism’ in this way divide over whether Plato’s views ever changed or “developed” throughout the course of his literary career. Those who claim to discern some development are, typically, referred to as ‘developmentalists,’ and those who deny that there is any or any substantial development are called ‘unitarians.’ I will have a good deal more to say about these two positions and their common use of the term ‘Platonism’ in the next chapter. For now, it is sufficient to distinguish this use of the term from another. In its third use, ‘Platonism’ refers to a consistent or at least comprehensive philosophical position maintained by followers of Plato, or ‘Platonists.’ Followers of Plato perhaps started declaring themselves to be Platonists—or were so designated by others—beginning in the first century BCE.2 By the first century CE, the self-designation was not uncommon. But even prior to the first century BCE, the absence of the term ‘Platonist’ (Πλατωνικὀς) certainly does not indicate that there were no followers of Plato who embraced ‘Platonism’ in this sense. What distinguishes this use of the term from the previous use is, among other things, the belief that Platonism extends beyond the dialogues. That is, elements of Platonism can be found in the testimony of Plato’s disciples—especially Aristotle—and also possibly within an oral tradition handed down from Plato himself through a chain of Academy members or “heads.”3
The use of the term ‘Platonism’ in this third sense is not in itself especially contentious. Contention immediately arises, however, if it is claimed that Platonism in this sense has anything to do with Platonism in the second sense. For to claim that the self-declared Platonists of antiquity embraced a philosophical position that is in essence the position that Plato himself embraced is to immediately open oneself to a barrage of criticisms. Though it may be conceded that ‘Platonism’ thus used may be inspired by or in some way have its roots in the Platonism of the dialogues, the idea that these are identical or nearly so seems far-fetched. In fact, the basically vacuous term ‘Middle Platonism’ and the originally pejorative term ‘Neoplatonism’ were coined to mark the putative difference between Plato’s own Platonism and what his disciples made out of that.4 It is perhaps worth stressing, though not with the intention of special pleading, that Plato’s disciples grouped under these two labels did not think of themselves as innovative or revolutionary or revisionist; they thought that they were articulating and defending and perhaps applying to new philosophical and religious challenges the philosophy found in the dialogues and, as indicated above, beyond the dialogues as well.
A not unreasonable response to this observation is that what these disciples thought they were doing need not impede us in a correct assessment of what they were actually doing, which is, from one perspective, something quite different from providing an exposition and defense of the pure stream of Plato’s thought. Indeed, we may plausibly add that in antiquity innovation was not especially valued; on the contrary, it was often held suspect. Accordingly, what may in fact have been innovative may either not have appeared so to proponents of the innovation or, if it did, there was motivation enough to conceal this. Nevertheless, if we could arrive at a perspicuous articulation of the Platonism of the disciples, we might be in a better position to see exactly where they went off the rails, so to speak. But, of course, to express the task in this way makes evident the obvious problem, namely, how do we articulate the “authentic” version of Plato’s philosophy found in the dialogues for the purposes of comparison?
One view has it that there are no philosophical position in the dialogues—at least none that reflect the beliefs of their author—and on this view, it would be vain to seek for Platonism there.5 That this view is, prima facie, an extreme one hardly counts against it. Perhaps it only appears to be extreme in comparison with views that only seem (incorrectly) reasonable or moderate. Though I will argue in the next chapter that this view is in fact untenable and incoherent, it does at any rate intensify the force of the challenge to show that there is any one philosophical position in the dialogues. By contrast, the developmentalists and the unitarians are in principle congenial to hearing an exposition of Plato’s philosophy (or, in the former case, perhaps we should say “iterations of Plato’s philosophy”), though they are more than a little resistant to the idea that this exposition will turn up something that is identical to a position held by philosophers some fifty or two hundred or five hundred or even eight hundred years later.6
I want to distinguish the above challenge from the challenge that developmentalists and unitarians set for themselves in offering expositions of Plato’s philosophy. For when they refer to ‘Platonism’ they typically mean something that, by definition, can be found only in the dialogues. According to the other use of the term, Platonism is indeed found in the dialogues, but these dialogues are a record or expression of Platonism understood more broadly; Platonism is not an inductive generalization from the data of the dialogues. This makes a considerable difference, as we will see. The claim that “Plato’s philosophy” is just the “sum” of what we find in the dialogues is fundamentally different from the claim that the dialogues are the best evidence we have for Plato’s philosophy. It is my contention in this book that the former claim is false and the latter is true. In addition, if Platonism is the philosophical position that Plato expressed, it does not follow that Plato was even the first to express it or that all subsequent expressions come from him or that he expressed it best (though I know of no Platonists who did not think that). It is only a trick of language that leads us to believe that Plato could not be a Platonist in this sense. For ‘Platonism’ substitute ‘wisdom’ or ‘truth about the world’ and it becomes immediately obvious that from the perspective of self-declared Platonists, it is reasonable to claim that Plato was a stellar Platonist.
Henceforth, for the purposes of clarity I will substitute for the term ‘Platonism’ the term ‘Plato’s philosophy’ when using it to refer to what is believed to be found exclusively in the dialogues. My central theme is, then, how Platonism is related to Plato’s philosophy.
I have hitherto used the vague descriptors ‘position’ or ‘view’ for what I am now calling ‘Plato’s philosophy,’ ignoring the obvious objection that there is a multitude of philosophical positions in the dialogues. After all, a ‘philosophical position’ can be a bare philosophical claim more or less limited in scope or one argument for that claim. In this sense, there are countless philosophical positions in the dialogues, including those held by Socrates’ interlocutors. On the view of developmentalists, there is no direct historically justified inference from the discovery of one of these positions to any other anywhere else in the dialogues. It may be the case that Plato maintained A in one dialogue; it is an open question whether he continued to maintain A in any other dialogue, or at least in any other dialogue in some antecedently postulated subsequent phase of his writing career. For example—and most obviously—to argue that in Phaedo and Republic Plato maintained something called a ‘theory of Forms’ is one thing; to maintain that this theory is part of the philosophical position that later came to be embraced and defended by disciples of Plato and that Plato was himself always a Platonist because he embraced Platonism thus understood is quite another. To take another obvious example, Socrates in Apology seems to evince agnosticism about the afterlife; Socrates in Phaedo argues for the immortality of the soul. Are either (or both) of these ‘positions’ attributable to Plato?
There does not seem to be an obvious non-question-begging way of distinguishing Platonism from Plato’s philosophy inductively by examination of the dialogues. Indeed, the problem of question-begging infects the inductive approach itself, since the salience that one gives to one claim rather than another must itself rest on some antecedently arrived-at view of what Platonism is. The epitome of this approach is paraphrase masquerading as philosophy. But failing to make such a distinction, the question of whether Plato was a Platonist has a banal positive answer. If, though, we are able to see our way to such a distinction, then the question of whether Plato was a Platonist at least becomes a substantive one.
In 1908, the great French scholar Léon Robin published a book titled La théorie platonicienne des idées et des nombres d’après Aristote.7 The book was an attempt to reconstruct Platonism entirely from evidence outside the dialogues, specifically, from Aristotle’s testimony. This methodology was intended precisely to avoid a question-begging inductive approach to the doctrines of the dialogues. One of Robin’s most notable conclusions is that, in line with Aristotle’s testimony, there are strong indications that Plato was tending toward what Robin calls ‘Neoplatonism,’ which is exactly what I am calling ‘Platonism.’8 I will in the third chapter have more to say about this conclusion and a number of others reached by Robin.
For now, I want to focus only on a problem with Robin’s methodology. That problem is that by deriving an account of Plato’s thought based exclusively on Aristotle’s testimony, Robin necessarily occludes the distinction between Platonism tout court and Plato’s own version of Platonism—if that is a suitable term for Plato’s philosophy. There is no doubt that Platonists of antiquity assumed such a distinction as odd as it might sound to us. The apparent oddness of speaking of Plato’s version of Platonism disappears once we realize that the term ‘Platonism’ is not one the self-declared followers of Plato used, at least at first. If one maintains that Platonism as described by Aristotle is identical with Plato’s philosophy, then there is nothing to occlude. If, though, as I maintain, ‘Platonism’ and ‘Platonist’ are just labels for a basic or general philosophical position and an adherent of that position, then it is absolutely crucial to distinguish Plato’s version of this from the position itself. As we will see, one of Robin’s other conclusions—namely, that Aristotle misinterprets Plato on a number of basic points—rests on the conflation of Platonism and Plato’s version of it. Indeed, as Robin himself concedes, Aristotle’s criticism of Plato frequently rests on Aristotle’s own Platonic assumptions. On the hypothesis of the proprietary nature of the label ‘Platonism,’ we can distinguish Platonism from Plato’s version of it, at which point the seeming paradox of Aristotle criticizing Plato from a Platonic perspective disappears.
Aristotle’s testimony is indispensable for determining the nature of Platonism as distinct from Plato’s version of it for the simple reason that Aristotle was himself a Platonist.9 Admittedly, this claim is not self-evident to everyone. I hope it will appear closer to being obvious rather than nonsensical once we make the above distinction. Aristotle’s version of Platonism is indeed at odds with Plato’s on many points. This does not even begin to undermine the claim that they were both Platonists. Take the following comparison. Martin Luther was certainly at odds with the Roman Catholic Church on many issues. This opposition has for a long time obscured the deep underlying harmony of Lutheranism and Catholicism on fundamental theological principles. Nevertheless, within the last two decades experts on both sides of this divide have come to the conclusion that there has always been an underlying harmony of principles despite the divergence in their application. Similarly, Aristotle’s ‘Protestantism’ can be understood as set in opposition to Plato’s ‘Catholicism.’ Often, this has been the case for extraneous reasons of a polemical nature. Yet if our aim is to understand the philosophical position that dominated philosophy for the largest part of its history, it certainly behooves us to step back from polemics and concentrate instead on the harmony that underlies the multitude of expressions of this position. If we can do this, one immediate bonus, or so I will attempt to show, is a better understanding of these various expressions.
So, if it turns out that Platonism is, to put it modestly, not a distortion of Plato’s philosophy, this will require us yet to distinguish Platonism from Plato’s philosophy, showing how the latter is actually one version of the former.
As a preliminary to the examination of Aristotle’s testimony, I want to begin with a hypothetical reconstruction of what I will call ‘Ur-Platonism’ (UP). This is the general philosophical position that arises from the conjunction of the negations of the philosophical positions explicitly rejected in the dialogues, that is, the philosophical positions on offer in the history of philosophy accessible to Plato himself. It is well known that Plato in the dialogues engages critically with most of the philosophers who preceded him.10 Some of these, like Parmenides and Protagoras, exercise his intellect more than others, including probably some unnamed ones as well as some unknown to us. All of these philosophers, with the exception of Socrates, are represented as holding views that are firmly rejected in the dialogues either explicitly or implicitly.11 It matters little for my purpose if Plato misrepresented or misunderstood some of these philosophers, though I do assume that he did neither of these things. I am not claiming that anyone, including Plato, simply embraced UP. I am, however, claiming that Platonism in general can be usefully thought of as arising out of the matrix of UP, and that Plato’s philosophy is one version of Platonism.12 So, in a manner of speaking, UP is a via negativa to Plato’s philosophy. To be a Platonist is, minimally, to have a commitment to UP. It is only a slight step further to recognize that this basic commitment is virtually always in fact conjoined with a commitment to discover the most consistent, integrated, positive metaphysical construct on the basis of UP. That is what Platonism is.
Since I am not claiming that Plato was an Ur-Platonist simpliciter, or merely an Ur- Platonist, I do not think I am subject to the above question-begging objection. What I want to show is that the substance of Plato’s thought as inductively arrived at by both developmentalists and unitarians can be seen to be built up from UP. More contentiously, and potentially more important, I will argue that we can give a better account of Plato’s philosophy than either developmentalists or unitarians can give if and only if we see that as a working out of the positive side of UP, that is, as a working out of what follows positively from the conjunction or unification of the denials of the positions of his predecessors. My hypothesis will also enhance our understanding of differences among Platonists, for as we will see, the further we go along a deductive line from the central idea of a first principle or principles of all, the less are the consequences or implications uniquely determined. Thus, it is perfectly possible that some Platonists should agree on first principles but disagree on what follows from these for, say, ethics or human psychology. It is equally possible that some non-Platonists, for example, Stoics, should arrive at conclusions about such matters that are similar or even identical to those of some Platonists even if they start from diametrically opposed principles.
UP is an ahistorical or theoretical framework for analysis, potentially open to a charge of being anachronistic. It should be noted that Plato himself employs such ahistorical frameworks for considering the views of his predecessors. For example, in Republic “lovers of sights and sounds,” apparently referring to no one in particular, are contrasted with philosophers; in Sophist pluralists and monists, idealists and materialists are lumped together ahistorically for criticism; and, indeed, the term ‘sophist,’ famously made a pejorative by Plato, is used to refer to those who actually held different views. In this regard, Aristotle just follows Plato in his categorization of various philosophical positions in order to submit them to criticism. The justification for my ahistorical hypothesis will, I hope, emerge as we proceed. Adherence to UP and to an integrated, systematic construct on its basis is what all Platonists share. Disagreements among these same Platonists are, I will try to show, best explained by the fact that this systematic construct does not decisively determine the correct answer to many specific philosophical problems raised especially by opponents of Platonism.
The elements of UP according to my hypothesis are antimaterialism, antimechanism, antinominalism, antirelativism, and antiskepticism. Much more will be said about the details of each of these ‘antis’ and their conjunction. For the present, a rough sketch will suffice.
Antimaterialism is the view that it is false that the only things that exist are bodies and their properties. Thus, to admit that the surface of a body is obviously not a body is not thereby to deny materialism. The antimaterialist maintains that there are entities that exist that are not bodies and that exist independently of bodies. Thus, for the antimaterialist, the question “Is the soul a body or a property of a body?” is not a question with an obvious answer since it is possible that the answer is no.13 The further question of how an immaterial soul might be related to a body belongs to the substance of the positive response to UP, or to one or another version of Platonism.
Antimechanism is the view that the only sort of explanations available in principle to a materialist are inadequate for explaining the natural order. What, then, distinguishes materialism from mechanism? It would be possible to be an antimaterialist yet still believe that all explanations are mechanical. Such might be the position of an occasionalist. Conversely, it would be possible to believe that materialism is true, but also maintain that there are nonmechanical explanations of some sort, say, at the quantum level.14 Antimechanism, though, seems to be derived from antimaterialism. That is, having rejected the view that everything that exists is a body or an attribute of a body, the way is open to propose non-bodily explanations for bodily or material phenomena. One way to understand antimechanism is as the denial of one version of what we have come to call “the causal closure principle,” that is, the principle that physical or material causes are necessary and sufficient for all events in the physical world.15 Although contemporary denials of this principle are generally focused on supposed mental events having at least no sufficient physical causes, antimechanism takes the stronger position that even admittedly physical events are not comprehensively accounted for by physical causes.
An antimechanist in antiquity generally relies on the principle that an ultimate or adequate explanation for a phenomenon must be a different sort of thing from that which is in need of an explanation. Thus, the principle of number, one, is not a number. Accordingly, one might argue that since the properties of bodies are not bodies, there is nothing in principle amiss in using bodies for accounting for these properties. Helen’s beauty, say, is accounted for by her body, perhaps by emerging from or supervening on it. In order to make this work, and to remain within the confines of the principle that that which explains must be different from that which is explained, it is necessary to maintain that the body itself, and not other properties of the body, is the explanation for the beauty. If it were other properties, then the original principle would be violated. But of course this way leads to shipwreck. For we either continue to explain properties by properties or we explain properties by bodies, but since the bodies are only differentiated by their properties, the explanation for Helen’s beauty will be the same sort of explanation as the explanation for Socrates’ virtue. Antimechanism and antimaterialism are distinct views, though within the versions of Platonism that arise from UP, they are always held to be mutually supporting.16 Along with antimaterialism, the exploration of the nature of explanation in an antimechanist framework belongs to a positive construct on the basis of UP.
Antinominalism is the view that it is false that the only things that exist are individuals, each uniquely situated in space and time.17 Nominalism can be local or general, denying the existence of anything other than individuals within one kind of thing or denying their existence generally. It can also be extreme, by denying that there can even be a multiplicity of individuals, since in that case each one would be the same as the other in virtue of the fact that it is one. The antinominalist thus allows that two or more individuals can be the same and still be unique individuals. He thus allows ‘conceptual space’ for sameness that is not identity. By contrast, the nominalist maintains that if two things are the same, then they are identical; if two things are not identical, they cannot be the same. An antinominalist could insist on the reality of the phenomenon of sameness in difference and yet deny that there is an explanation for this, claiming rather that it is just a brute fact. Platonists generally associate the acceptance of the phenomenon with at least the possibility of giving a substantive causal explanation for it.18
Antirelativism is the denial of the claim that Plato attributes to Protagoras that “man is the measure of all things, of what is that it is and of what is not that it is not.”19 The claim is expressed in two forms in the dialogues: one epistemological and one ethical. Epistemological relativism is not skepticism; hence, the denial of this form of relativism is not a denial of skepticism. One may, after all, be skeptical of the possibility of acquiring knowledge about properties that may well be objective. Relativism is the view that ‘true’ just means ‘true for me’ or ‘what appears true to me’ or ‘true for some particular group.’ The ethical form of relativism maintains that ‘good’ just means ‘good for me’ or ‘good for the group’ where good is determined by or constituted by a mental state or states, roughly, pleasure broadly conceived. Thus, ethical relativism is virtually hedonism in some variety. The denial of ethical relativism—individual or social—holds that what is good is determinable independently not of what is good for someone, but of what appears to that person as good for him. Thus, the antirelativist can maintain that ‘good’ is the same as ‘good for x’ so long as she insists that ‘good for x’ is not equivalent to what x claims is good for x. A similar point can be made about epistemological relativism. An alternative way of expressing ethical antirelativism is to maintain that goodness is a property of being; for epistemological antirelativism, the analogue is truth is a property of being. For the Platonist, the logical connection between goodness and truth is accounted for by being itself.
Antiskepticism is the view that knowledge is possible. Knowledge (ἐπιστήμη) refers to a mode of cognition wherein the real is in some way “present” to the cognizer. The skeptic does not maintain that cognition generally is impossible, but only that knowledge is. According to the argument we get in the dialogues, if either materialism or nominalism were true, skepticism would follow because it would not be possible for the real to be present to any cognizer; there could only be representations of some sort of the real, representations whose accuracy would be indeterminable.20 Throughout the dialogues, Plato has Socrates rail against sophists, rhetoricians, and various demagogues who share at best a cavalier attitude toward the need for knowledge of any sort.21 Plato’s antiskepticism assumes the legitimacy of such attacks.
There is, as I have already admitted, no way of decisively proving that Plato, apart from the dialogues, actually embraced these elements of UP. The best I can do is show how much of the actual form and content of the dialogues make sense when we see them as built on a conjunction of the above five ‘antis’ and an attempt to unify them in some way. But it is worth here pointing out, I think, that if Plato is, say, a crypto-materialist, masquerading as an antimaterialist, that would make him the worst kind of sophist. It would make his apparently relentless condemnation of sophistry and ‘counterfeit philosophy’ in the dialogues more than ironic. It would suggest a man with a psychological makeup that can be characterized only as pathological. And more to the point, it would suggest that the man for whom Aristotle had the greatest respect was basically a fraud. Yet there is no evidence whatsoever that Aristotle thought this to be the case or that he took Plato as anything other than a serious philosopher, indeed, the touchstone of his own philosophy.
Obviously, there is a large but not infinite range of possible positions consistent with being antimaterialist, antimechanist, antinominalist, antirelativist, or antiskeptic. For example, an antinominalist is not necessarily an antimaterialist, as I have defined that. The antinominalist position known as ‘conceptualism’ does not entail that concepts are immaterial entities as opposed to properties of material entities. Nor is an antimaterialist necessarily an antinominalist, as is evident, for instance, in the philosophy of, say, William of Ockham. Nor is an antimechanist necessarily an antinominalist. If, though, we begin to explore logical or explanatory connections among the five ‘antis,’ the range of positions begins to narrow. Thus, if one is an antimaterialist because one is an antinominalist, a number of possible positions are eliminated. For the UP of the dialogues, antimaterialism is, for example, entailed by the only possible explanation for the supposed datum of two nonidentical things nevertheless being the same.
Continuing along this line of thought, ethical or epistemological antirelativism does not require the embrace of antimaterialism or antinominalism. If, however, it turns out that the only way to make plausible the justification for a claim about the objectivity of the good or of reality itself is to hypothesize the existence of an immaterial entity, commitment to antirelativism at least provides one reason for commitment to antimaterialism.22 And antinominalism is thereby supported. As we have already seen, antimaterialism at least opens the way for antimechanist explanations. Finally, though antiskepticism is itself the basis for a host of “dogmatisms,” among which are many contradictory positions, antiskepticism yields an increasingly focused range of options for one who is also an antimaterialist, antinominalist, and antirelativist.23
The appropriate context for connecting all the elements of UP is explanatory. That is, the general reason why Plato rejects nominalism, materialism, etc., is that these positions render impossible the explanation for the phenomena they are supposed to explain. So, for example, the phenomenon of two or more things having an identical property cannot be explained by nominalism. Or the existence of human cognition cannot be explained by materialism. Or the objectivity of human nature cannot be explained by relativism. The elements of UP belong to an explanatory framework. In constructing this framework, Plato is in one respect perfectly in line with his Pre-Socratic predecessors. That is, he assumes that the true explanatory framework will converge on the minimum number of principles.24 Thus, Plato assumes that nature (ϕύσις) is an orderly arrangement of its parts (κὀσμος). As we will see, this reductivist tendency is a key facet of Platonism. It serves as a constraint on philosophizing within the framework of UP. So a multitude of principles—especially principles that are unrelated—are prima facie suspect with regard to their explanatory power. Just as modern theoretical physics assumes that the four ‘fundamental’ forces in nature must be explanatorily connected, so those who embraced UP assumed that the elements of their positive constructs needed to be unified in some way. The default unifying framework will be a fundamental metaphysical theory of some sort. Indeed, the principal reason that later Platonists attributed a metaphysical theory to Plato was the assumption that without that it would not be possible to unify the elements of UP. And without such unification, the positive doctrines would lack a highly desirable mutual support.25
Another way to characterize UP is as fundamental antinaturalism, that is, the philosophical position according to which naturalistic or bottom-up explanations for all problematic phenomena are in principle insufficient.26 The positive construct on the basis of UP may be aptly termed, following Norman Kretzmann, ‘Grandest Unified Theory.’27 Kretzmann’s subject is the natural theology of Thomas Aquinas in his Summa contra Gentiles, what he characterizes as a “rational investigation of the first principles and most fundamental aspects of reality in general and human nature and behavior in particular” (23). But this characterization aptly expresses the task all Platonists share. UP simply articulates the opposition to the set of philosophical positions that would make this task impossible or at least radically different from what all Platonists took it to be.28
The assumption that a positive response to UP will be a unified explanatory framework has an immediate and portentous consequence. This consequence is that the explanatory framework will have to be in some sense hierarchical. The unification will consist in showing that which is in need of an explanation other than itself is explained by that which is not—the ‘heteroexplicable’ requires the ‘autoexplicable,’ the ‘stopping point’ of explanation. As a principle of metaphysics, this means that the autoexplicable has ontological priority over the heteroexplicable. All versions of Platonism introduce some sort of hierarchy into the explanatory framework.29 The basic hierarchy posits the ontological priority of the intelligible realm to the sensible. But this leaves open the difficult question of hierarchy within the intelligible and sensible realms. Throughout the history of Platonism, as intrahierarchical analysis proceeded, the complexities pertaining to unification seemed to multiply.
To claim that the elements of UP belong to an explanatory framework over against the frameworks provided by the positions UP rejects leaves open the essential question of the explananda. Thus, for example, antinominalism adheres to a principle that nominalism cannot explain the phenomenon of sameness in difference or, stated otherwise, the phenomenon of ‘things’ possessing properties that they do not exclusively possess. Nominalism is not an alternative explanation for this phenomenon, since it rejects its existence, even its possibility. The positive constructs that constitute the versions of Platonism do not generally engage directly with their opponents over the existence or possibility of such a phenomenon. Indirectly, Platonists seek to show that, in the above example, sameness has a nature different from identity that, if true, makes it at least intelligible how two things that are not identical can yet be the same.
With respect to skepticism, the phenomenon to be explained is obviously not knowledge, but rather rationality, as Sextus Empiricus would so clearly see. Knowledge is not the explanandum for the simple reason that even one who believes that knowledge is possible (like Socrates) might well claim not to possess it. The Platonists want to argue that our ability to reason or make rational judgments could not be explained unless we either already possess knowledge or we are capable of possessing knowledge. Knowledge is here the explanans, not the explanandum. Another way of indicating the phenomenon is to say that humans possess a mode of cognition that animals do not. This mode of cognition—which even the Skeptic manifests in reasoning to the denial of the possibility of knowledge—cannot, the Platonists maintain, be explained unless we are knowers.30
The materialist denies the existence of any immaterial entities. The proponent of UP holds that the only possible explanation for the above phenomena requires the rejection of materialism. In this sense, antimaterialism is a derivative or second-order element of UP. It does not offer an explanation for an independently ascertainable phenomenon.31 Similarly, the mechanist denies the phenomenon of purpose in nature, something that could be possible only if there were a being or beings capable of making judgments about the future, which in turn is possible only if they possess knowledge or the possibility of acquiring it. Teleology in nature, which is what antimechanism seeks to explain, appears to be a real phenomenon only if antimaterialism is true. And antimaterialism follows from the explanations for the phenomena that constitute antinominalism and antiskepticism.
Finally, antirelativism is supposed to be the starting point for accounting for the phenomena of objective or interpersonal reality. To deny that ‘true’ is equivalent to ‘true for me’ is as much as to claim that there is a world independent of any judgments made about it and that things in this world have the property of objective truth.32 To identify objective reality as a ‘phenomenon’ that needs to be explained is problematic on at least two counts. First, a phenomenon, as Protagoras would no doubt point out, must be contrasted with reality. Second, what are the grounds for assuming that reality needs any explanation at all? The proper response to the first problem is to show that there is a distinction between epistemic and nonepistemic phenomena. The former entail the existence of objective reality; the latter do not. What Plato and later Platonists maintain is that epistemic phenomena are explicable only if relativism is false. So it is not reality that needs explaining but epistemic phenomena; objective reality is the explanation for these phenomena. The particular task of the Platonist is to show that the explanation for these phenomena so defined is not circular. Naturally, the Platonist will be able to recur to the argument that concludes to the possibility of knowledge to support the noncircularity of the claim that only objective reality explains epistemic phenomena.
A pertinent objection to the above analytic framework is that it is otiose. If, indeed, Plato is a systematic philosopher, we need only start from the elements of the system—in the dialogues and in the indirect tradition—not from a putative matrix, UP, out of which the system arises. In reply to this objection, the main problem with coming to grips with Platonism is arriving at a non-question-begging definition of it. Assuming, charitably, that Plato is himself consistent, how is it that philosophers who disagree about doctrine can both rightfully declare themselves to be followers of Plato? Indeed, how is it that apparent differences in doctrine in the dialogues can all be held to be elements of Platonism? One considered response to the first question is to maintain that fidelity to Platonism is actually a multifarious fidelity to Plato himself.33 The usual response to the second question is to maintain either that (a) there is no systematic unity throughout the entire corpus; or else (b) that the ‘system’ is localized to a particular set of dialogues; or that (c) it is detachable from the dialogues altogether. As I will argue, (a), (b), and (c) are unsustainable based on both the indirect evidence and the dialogues themselves. But this fact does not preclude changes in doctrine across dialogues. Nor does it preclude disagreements among Platonists. These changes and disagreements all occur within the commitment to UP and to the construction of a unified system on its foundation. Not only is a commitment to UP what Plato and virtually all Platonists share, but recognizing this commitment allows us to see what in fact underlies the many disputes we will encounter.
In this book, I am going to explore the hypothesis that self-proclaimed followers of Plato or ‘Academics’ took Plato’s philosophy to be a positive, integrated response to UP.34 It is perhaps somewhat disingenuous to attribute to Platonists the view that Plato held merely a positive construct out of UP as opposed to their really claiming that Plato expounded “the very best possible construct that any philosopher has hitherto delivered unto mankind.” Nevertheless, the point that Plato’s philosophy is a response to UP and not UP itself is crucial for the simple reason that no one supposed that a philosophical position could be constituted in the negative, as it were. This is so because a philosophical position was generally thought to follow from a particular “way of life” (βιὀς), whereas the opposition to, say, nominalism in itself does no such thing.35 The interesting exception that proves this rule is Pyrhonnian Skepticism, which alone held that a total rejection of commitments to any beliefs did actually constitute a way of life, but only in the special sense that absence of commitment produced an otherwise unobtainable psychic tranquillity. For this to work, however, the rejection of belief had to be complete; a rejection of some or many beliefs in favor of others was simply another form of dogmatism.
Thus, I am maintaining that UP is the matrix out of which Plato’s version of Platonism arises. Stated otherwise, UP provides the initial set of principles on the basis of which Plato proposed to address the gamut of philosophical problems and puzzles that he had inherited from his predecessors. It is sometimes easy to forget that the philosophical ‘schools’ of antiquity were in substantial agreement about what philosophy aimed to accomplish despite their differences about methods and results. The shared affirmation of wisdom (σοϕία) as life-enhancing understanding of the cosmos underlies the divergent views and arguments. For this reason, it would be astonishing if the elements of UP as found in the dialogues were not intended by their author to serve as the substructure for the systematic superstructure that the abundant direct and indirect evidence reveals.
It might be objected that terms like ‘materialism,’ ‘mechanism,’ ‘nominalism,’ ‘relativism,’ and ‘skepticism,’ as well as those terms that indicate their opposites, can only be anachronistically attributed to Plato. I concede the truth in the claim that Plato would not have called himself an ‘antinominalist.’ I deny, however, that it is misleading to say that UP has antinominalism as a constituent part. As in the present case, such terms need only serve as labels, the contents of which must be specified. When such specification occurs, calling the Megarian position nominalist or Zeno’s defense of Parmenides extreme nominalism need occasion no distortion. In any case, UP is no more Plato’s position than is “Romance” the name of the language spoken by Dante, Pascal, and Cervantes.
In attempting to assess the relationship between Plato’s philosophy and Platonism, we must confront the following issue. A historian of philosophy must acknowledge that if a philosopher S makes a claim A, and if, in fact, A entails another claim B, it does not follow as a historical fact that S actually embraced B. Another philosopher, T, disciple of S, may grant the above historical point yet at the same time insist that those committed to A, like S and T, are also committed to B whether they are aware of this or not. Now, where S = Plato, A = one element of UP, and B = one element of Platonism, the question of Plato’s commitment to Platonism becomes ambiguous according to whether our question is about the history of philosophy or about philosophy itself.
I provide here two particularly revealing examples of an A and a B from Republic and from Timaeus. In subsequent chapters, we will meet many others. The first example concerns the Divided Line of Republic book 6.36 As Socrates describes the bottom section of the Divided Line, he terms ‘images’ (εἰκὀνες) things like shadows and reflections in water, and the originals of which these are images are animals, plants, and manufactured things. In the top section, he says that mathematicians use sensible originals as images of those things for which they are seeking understanding, namely, things like the Square or the Diagonal themselves.37 Socrates does not actually say that there are ‘Mathematical Intermediaries’ that are the images of Forms. That is, he does not say that there is an ontological class corresponding to the mode of cognition that is διάνοια, that which the mathematicians employ.38 Aristotle does not hesitate to claim that Plato believed in Mathematical Intermediaries or objects, and virtually the entire Platonic tradition is in agreement that these objects do have an ontological status, which is that of images of Forms.39 Leaving aside for the moment the issue of whether Aristotle’s testimony is an inference from a reading of Republic or, what is more likely, based on discussions with Plato himself, are Platonists correct to infer that Plato is committed to mathematical intermediary objects and to the equally portentous proposition that these objects are images of Forms? The former inference sets us squarely before the problem of the nature of mathematical intelligibility, as we will see. The latter inference, if sound, seems to entail that imagery is a fundamental ontological notion for Platonism, not merely localized to shadows and reflections in mirrors.
The second example is from Timaeus. Timaeus says of the motive for Demiurge producing the cosmos, “He was good, and in that which is good no grudging ever arises with respect to anything. So, since he is ungrudging, he desired that all things should come as near as possible to being like himself.”40 Just one page further on, the motive is again addressed, “for the god, wishing to make this cosmos most nearly the same as the intelligible thing that is best and in every way complete, constructed it as one visible thing, containing within it all living things in nature that are of the same kind as it.”41 A seemingly simple inference made from taking these two statements together is that the Demiurge and the model that the Demiurge uses are identical or the same. This inference is reinforced by the description of the intelligible model as itself “an intelligible living animal” (νοητὸν ζῷον), containing within it all the living creatures that are to be the specific models for the living creatures in this cosmos.42 We may interpret the inference to mean that the cosmos will be like the Demiurge because if it contains instances of all the kinds of animals, it will be like the Demiurge, who has within himself thoughts of all of these kinds. Or we may interpret the inference to mean that the cosmos will be like the Demiurge because if it contains instances of all the kinds of animals, it will be like the Demiurge, who is identical with the living creature.
Which of these two interpretations—leaving aside the possibility that there may be others—is likely to be the one that Plato would endorse? More to the point, what are the hermeneutical and philosophical principles that should be applied in deciding the matter? It may seem obvious that one principle at least is that we should opt for the interpretation that is consistent or most consistent with what Plato says elsewhere. But this is far from uncontentious. First, the use of such a principle assumes that Plato’s views are more or less consistent throughout the dialogues, something that developmentalists would deny. Second, consistency is a weak hermeneutical criterion. Both of the above interpretations might well be consistent with what Plato says elsewhere. In particular, Plato might not have had himself a settled notion of how, given that the cosmos is to be made like the Demiurge and also like the Living Animal, the Demiurge is related to the Living Animal.
It is my contention that the appropriate criterion to apply in deciding on the correct interpretation of implications of the two Timaeus texts is consistency with UP. I mean that the proper question to ask—proper in the sense that it is the primary question that self-declared Platonists asked in coming upon difficult or ambiguous claims in Plato—is which interpretation is going to be part of the maximally consistent positive construct one can make on the basis of UP. Since the matter very quickly becomes quite complicated, conscious employment of this criterion would likely account for many of the variations in doctrine within Platonism. We should also not ever forget the obvious but somewhat sobering fact that not all self-declared Platonists were equals in philosophical acumen. The fact that they thought one interpretation to be the authentic part of the positive construct is hardly sufficient for our thinking it so. Nevertheless, in the present example, a commitment to antiskepticism—that is, to the possibility of knowledge—will, I believe, be seen to favor one interpretation over any other, assuming of course that the Demiurge is, paradigmatically, a knower. I mean that given an adequate account of knowledge, we can infer that the Demiurge’s knowledge of the Forms guarantees his identity with them in some sense.
In subsequent chapters, I will try to show that UP is itself consistent and that Plato’s dialogues reveal him working out what he takes to be the necessary consequences of commitment to UP. It is no exaggeration to say that many of these consequences are extreme, at least from the perspective of anyone who holds one or more of the positions Plato rejects. It is, though, no part of my story that adherence to UP can consistently produce only one set of results. Indeed, one of my main conclusions is that Platonism is a big tent and that within that tent are found parties disputing numerous issues. A salutary exercise for anyone supposing Platonism to be a monolith is a perusal of Proclus’s survey of Platonic interpretations of Plato’s dialogue Parmenides, a work that is for Platonists a central text used for finding the correct path from UP to Plato’s version of a positive construct.43 In his commentary, Proclus catalogs an impressive number of mutually inconsistent interpretations of that dialogue offered by Platonists. When Plotinus averred—ruefully, I imagine—that Plato sometimes spoke “enigmatically” about human freedom and the soul, he was indirectly confirming that adherence to UP did not automatically yield answers to basic and even urgent philosophical questions.44
We can assure ourselves that the Platonic ‘tent’ is not infinitely large or perhaps even very large merely from the ‘anti’ pillars that support it. For example, Atomism is excluded by UP’s opposition to materialism and to nominalism. So, apparently, is the philosophy of Anaxagoras, or any other of the so-called pluralist responses to Parmenides. A philosophical position that took hedonism to be the most plausible version of ethical relativism would also be excluded. A Pyrrhonist could embrace neither the antiskepticism of UP nor the positive assertions that constitute the contradictions of the other ‘antis.’
There is, though, one philosophical position that might be thought both to endorse UP and to be opposed to Platonism at the same time. That is the philosophical position of Aristotle. Aristotle’s supposed anti-Platonism might be thought to follow from a rejection of one or more of the elements of UP. Yet in fact there is abundant evidence in the Aristotelian corpus that Aristotle argued strenuously for each of the five ‘antis.’ On what grounds, then, are we to suppose that he is an anti-Platonist as well? Perhaps it will be maintained that his opposition to a theory of Forms is sufficient to warrant his anti-Platonism. In that case, given that Aristotle is committed to UP, we would have to say that Aristotle did not believe that a theory of Forms is entailed by UP. If this is so, then we will have to ask if there is any sense in claiming that a philosophical position that rejects a theory of Forms can be said to be a version of Platonism, particularly if some Platonists at any rate want to insist that UP does entail a particular theory of Forms. Before we can answer this question, we will have to consider what exactly Plato’s own commitment to a theory of Forms amounts to. It is, for example, evident from a passage in Sophist that Plato did not endorse every theory of Forms.45 In addition, we have to contend with the possibility that Plato’s views about Forms changed, so that it is not possible to speak of ‘the’ theory of Forms and Plato’s view about its derivation from UP.
More generally, we have to be clear about how any theory of Forms stands in relation to the basic or generic justification for the claim that nominalism is false. I am here referring to the core commitment of anyone who holds that sameness is distinct from identity, that is, that two or more things can be the same though they are not identical. Indeed, since sameness is a two-term relation, the nonidentity of things that are the same necessarily follows. If Aristotle may be assumed, like Plato, to believe that nominalism is false—Aristotelian science, which is of the universal, would not be possible if this were not so—then Aristotle must share this core commitment.46 From this core commitment follows the particular justification for the possibility of sameness among things that are nonidentical. No doubt, there are incompatible justifications possible. We need to ask whether any proposed justification amounts to a theory of Forms. Alternatively, we might ask whether a theory of Forms follows from UP. If the answer to either question is no, then Aristotle’s commitment to UP is not shaken by his rejection of one or more theories of Forms.
Consider the matter from a slightly different perspective. Aristotle in his Nicomachean Ethics delivers a multifaceted sustained argument against the existence of an Idea or Form of the Good.47 And yet Aristotle apparently sees no incompatibility with this position and his claim in his Metaphysics that the unique primary referent of ‘being’ is also the unique primary referent of ‘good.’48 We may well want to insist that this primary referent, the Unmoved Mover, is not the Idea of the Good. If, though, the Idea of the Good is a hypothetical entity postulated to explain certain phenomena, and if the Unmoved Mover is also a hypothetical entity postulated to explain the same phenomena, the fact that they are not identical does not gainsay the fact that they are doing the same sort of explanatory job.49 If that is the case, one might well wonder what the addition identity conditions are that would lead us to hold that they are not identical. As we will see, the early history of Platonism abounds with examples of philosophers variously explaining or accounting for phenomena that anyone committed to UP will want to explain and anyone not committed to UP will think require no explanation at all. Aristotle’s Unmoved Mover, it will turn out, is not the starting point for an anti-Platonic system, that is, for a system that rejects UP, but rather the starting point for a version of Platonism that assumes UP.
There were self-proclaimed disciples of Plato whose attachment to any theory of Forms seems to have been no stronger than Aristotle’s. And yet these Academics evinced an unalloyed commitment to UP. The usual accounts of Speusippus’s rejection of Forms and of Xenocrates’ identification of Forms with Numbers assume a deviation from Platonism, including, implicitly, a rejection of UP. It will, I hope, be more illuminating to see the Old Academy as engaged in an ongoing debate about the implications of a commitment to UP. In particular, this debate surrounds the nature of the nonmaterial or intelligible realm and its relation to the material realm. The antimaterialist claim is inseparable from some claim about the identity conditions for nonmaterial entities. In other words, it must provide an account of just what makes intelligibles intelligible. That this problem is at the foundation of one of the central themes in Platonism is incontestable. Equally incontestable, in my opinion, is Plato’s growing awareness that the solution to this problem had to be set within mathematical terms. I mean that at some point—perhaps quite early in his career—Plato came to hold that intelligibility was essentially a mathematical concept. Thus, Xenocrates’ apparent claim that Forms are Numbers is, minimally, to be seen as a continuation of the Academic discussion about the lineaments and applications of a positive construct on the foundation of UP. By contrast, our knowledge of the philosophy of Speusippus is so meager that we can scarcely arrive at a firm judgment about what his Platonism might have amounted to. Nevertheless, his assumption of a mathematized theory of the intelligible realm seems likely from the Aristotelian evidence. As I will argue, his so-called epistemological holism is in line with what Plato himself thought knowledge must be if knowledge is of intelligibles and if intelligibles are mathematical. And, as already mentioned, if knowledge so construed is not possible, explanatory adequacy within the ambit of materialism and mechanism remains untouched. So, too, for relativism.
The Skeptics of the New Academy, as it was called by doxographers, provide an interesting test case for the usefulness of UP as an analytic tool.50 How can one be a Skeptic and an adherent of UP? We should admit at once that there is no guarantee that self-proclaimed members of the Academy are bound to follow Plato in any regard. We know so little about the operation of the Academy, whether in Plato’s own time or after, that it is purely speculative to treat any philosopher said to be a “member” of the Academy as obliged to adhere to any philosophical position. And yet there was presumably some point in associating oneself with the Academy and hence with its founder. For the Academic Skeptics, the point was, I take it, that there was in Plato’s written works or in his philosophy as known from outside the works something thought to be congenial to skepticism. The first thing that comes to mind in this regard is ‘Socratic ignorance,’ as explicitly claimed by Socrates in the dialogues.51 But ignorance is not skepticism. Socrates in fact nowhere claims that it is not possible for a human being to know the things that he claims not to know, such as the definitions of the virtues.52
There is, however, an important passage in Phaedo in which Socrates seems to agree that it is not possible for human beings while embodied to attain knowledge.53 That is, a separation of soul from body is required in order for knowledge to be acquired by us. This assertion is made prior to an argument that we already possess knowledge as a condition for our making certain judgments we do actually make about the properties of things.54 So, obviously, the knowledge we possess now is something distinct from the knowledge that we are supposedly unable to acquire here below. In another dialogue, Theaetetus, the distinction between the two sorts of knowledge is made abundantly clear: it is the distinction between the knowledge we “possess” (κεκτῆσθαι) and the knowledge we “have” (ἔχειν).55 The former is somehow “in” us; the latter is the realization or actualization or awareness of the former.
Should we take Academic Skeptics to be arguing for skepticism on the grounds that we do not “have” knowledge or we do not “possess” it? One might well wonder how one could argue for the former conclusion without arguing for the latter. But to argue for the latter requires at least that we confront the Recollection Argument, which maintains that we must “possess” knowledge if we are to make judgments that even a Skeptic would find difficult to gainsay. Indeed, as it will turn out, the Skeptics’ argument against the possibility of knowledge is directed against a Stoic account of “having” knowledge, not a Platonic account of possessing it. An argument against a Platonic account of the possibility of having knowledge might be at the same time an argument against possessing it. This is just the sort of argument that Pyrrhonists employed. But it might not be that. The Skeptics’ argument against the possibility of having knowledge is different from the reasoning employed in Phaedo against our having knowledge while embodied. My aim is not the forced recruitment of Academic Skeptics into the ranks of Platonists, but rather that understanding what a commitment to UP involves requires that we set aside contemporary presuppositions about knowledge. To say that Plato was an antiskeptic is not anachronistic; to say that he was an antiskeptic on behalf of a contemporary understanding of empirical knowledge is. Plato’s antiskepticism will, as we will see, turn out to be inseparable from his antimaterialism. And a commitment to UP will be seen to be broad enough even to include a certain sort of skepticism, namely, that which we find in Phaedo regarding the having of knowledge while embodied. It will also be seen to be compatible with the sort of skepticism that labels the account of the sensible world in Timaeus merely a “likely story.”56
The construction of versions of Platonism among the so-called Middle Platonists presents us with a number of problems. Certainly, not the least of these is the distressing dearth of textual evidence. Two paths of Middle Platonism, though, stand out as particularly useful for understanding the possibilities within UP. The first is found principally in the works of Antiochus of Ascalon (130–68 BCE), who wanted to show that Platonic ethics and Stoic ethics are really the same thing. The second is found principally in the works of Numenius (second half of second century CE), who sought out an integrated Platonic account of the intelligible world.
Stoic ethics has been viewed, even in antiquity, either as Socratic-inspired or Platonic-inspired. When these two views are seen to be distinguished, Socratic ethics is being contrasted with Platonic ethics; in the second way, as with Antiochus, no distinct Socratic ethics is discernible. This dispute raises an important question about positive implications of antirelativism in ethics. Moreover, it invites us to consider how the other elements of UP contribute to these implications.
In a text of Aristotle to which we will return at some length, Aristotle says that Plato’s commitment to a separate intelligible realm began as a youth (ἐκ νεὀυ).57 Without doubt, then, this commitment antedates any of the dialogues supposed to reveal an account of Socratic ethics that is distinct from Platonic ethics. Given this, we have to decide if the claims made by Socrates in these dialogues are claims that entail no such commitment. Granted, it is possible that Plato’s commitments are irrelevant to his exposition of Socratic ethics and that these commitments actually constitute an unwarranted adumbration. We might, for example, want to maintain that the firm commitment to all the elements of UP or to things that entail these elements in Republic do not necessarily have anything to do with Socratic ethics. It might be supposed, for instance, that in Republic Plato’s tripartitioning of the soul allows for the sort of irrational acting that is not possible in Socratic ethics. We might want to argue that Plato’s outlandish belief in the immortality of the soul has no bearing on unalloyed Socratic insights. Socrates’ apparent agnosticism about the afterlife in Apology in contrast to Socrates’ argument for it in Phaedo might be thought sufficient in itself to separate Socratic ethics from Platonic ethics. In order to arrive at this conclusion, we would have to suppose that Plato went through a ‘Socratic phase’ before he transformed Socrates into a representative of his own Platonic position. This is not an unreasonable approach, though it requires a commitment to some type of developmentalism, a commitment that may on other grounds be found difficult to maintain. For example, it requires a certain amount of waffling in regard to Gorgias, in which Socrates directly expresses a belief in the immortality of the soul (as part of his ethical argument), and Meno, where a commitment to immortality—or at least to preexistence—is implied by the theory of recollection. Are Gorgias and Meno ‘early’ Socratic dialogues or ‘middle’ Platonic dialogues or works that are ‘transitional’ from one phase to the other?
Antirelativism in ethics is, for Plato, obviously going to have something to do with the positing of an Idea of the Good. Is this true for a putatively distinct Socratic ethics? Presumably not, according to Aristotle, who claimed that Plato, not Socrates, separated the Forms.58 But then we must ask how a ‘nontranscendent’ or ‘this-worldly’ Socratic ethics is supposed to work. That is precisely the question that a Stoic would feel needed to be answered if he wanted to claim Socratic as distinct from Platonic inspiration.
One of the most difficult facets of the philosophy found in the Platonic corpus is the articulation of the intelligible realm leading up to (and down from) the Idea of the Good. The combination of antiskepticism with antimaterialism yields the problem of what entities populate the intelligible realm and how these entities are distinguished among themselves. As we will see, the variety of versions of Platonism can be arrayed along a quantitative axis wherein at one end a unique intelligible entity is posited, and at the other end an actual infinite number of entities are maintained. In order to see this range as other than arbitrary, we have to inquire into the criterion for the positing of intelligible entities in the first place. Broadly speaking, the criterion is explanatory adequacy, that is, the postulation of the necessary and sufficient causes of phenomena needing to be explained. Thus, for example, if the phenomenon is sameness in difference, the criterion will lead the Platonist to hypothesize a cause that can only be intelligible, that is, nonmaterial. If the phenomenon is the intelligibility of sensible reality, then, according to one interpretation of the meaning of ‘intelligible,’ the criterion indicates an intellect as cause. If the phenomenon is cognition itself, then the criterion leads us to explain the nature of the objects of cognition such that cognition is possible. And so on.
There is, it appears, a problem with adequacy and redundancy in such explanatory criteria. I mean that it is not clear why more than one intelligible entity is required for any and all explanations. Thus, Plato hypothesizes an eternal intellect, an array of intelligible objects, and a superordinate Idea of the Good. Aristotle collapses into one entity the three functions that these three hypothetical entities are intended to serve. Aristotle’s Unmoved Mover does what Forms, the Demiurge, and the Idea of the Good are supposed to do, according to Plato. Conversely, later Platonists will argue how and whether to reconstruct a dyad or a triad of intelligible entities in spite of Aristotelian arguments to the contrary. It is my contention that these arguments occur within the framework of UP and the further commitment to a unified positive construct on its basis.
Consider the rather narrow question of whether the virtues are one or whether we need to hypothesize an intelligible entity for that which each virtue’s name names. The issue seems to have puzzled Plato in his Protagoras. That there be some intelligible entity to explain the possibility of someone possessing the property of, say, courage, is not in question. Whether this is the same entity as that which explains the possibility of someone possessing the property of temperance or not is what is at issue. It might seem obvious that if there is a justification for positing a Form of Courage, then there is equally a justification for positing a Form of Temperance. And yet if both Courage and Temperance are virtues, perhaps only a Form of Virtue is needed. Or perhaps a Form of Virtue is needed in addition to separate Forms of Courage and of Temperance. How are we to decide this question? The fact that there is no one obvious way to settle the matter, one way that excludes all others, should lead us to predict that philosophers seriously committed to UP may arrive at differing conclusions.
Among the so-called Middle Platonists like Numenius and others, it was evidently not thought that the first superordinate principle of all could itself be bereft of intellect. But at the same time, its intellectual properties did not lead to the collapse of a secondary demiurgic intellect into it. If the first principle of all actually is an intellect, then apart from all other considerations, the Platonic bona fides of Aristotle is enhanced. It is extremely difficult to say if Numenius believed that in making the first principle an intellect he was interpreting Plato or drawing out the consequences of UP regardless of what Plato himself might have actually held. Indeed, it is difficult to say whether Numenius would have distinguished these two options. This possibility always exists owing to the tentative nature of the dialogues and the well-established existence of an oral doctrine of Plato.
One of the arresting features of the fragmentary evidence of Middle Platonism is the consensus that some sort of divine and separate intellect or νοῦς is the key positive doctrine reflecting antimechanism. And yet the relation between such an intellect and the Forms that are the focus of the positive doctrine following from antimaterialism is disputed. This is equally the case for the relation between this intellect and the Idea of the Good, the focus of the positive doctrine following from antirelativism. As we will discover, many of the debates among the Platonists themselves arise from different understandings of what an intellect is and what its distinctive role is, not just in relation to the material or sensible realm, but within the intelligible realm as well.
When Proclus declared in his Platonic Theology that Plotinus was one of the great exegetes of the Platonic ‘revelation’ (ἐποπτεία), he meant more than that Plotinus was an exceptional interpreter of the dialogues.59 He meant in addition that Plotinus systematized on the basis of the dialogues, the oral tradition, and Aristotle’s testimony, the most coherent and comprehensive version of a positive philosophy based on UP. Even this extraordinarily high praise does not prevent Proclus from criticizing Plotinus on many more or less central points. Still, it was Plotinus, according to Proclus, who narrowed the number of logically supportable versions of Platonism. Stated differently, he narrowed the range of issues that were debatable. Some of these issues arise from circumstantial disputes of which Plato could not but be ignorant. Others regard the properties of the intelligible entities that Plato himself posited.
Plotinus tells us that he considered himself to be nothing more than an exegete of Plato; he would certainly have eschewed the title of ‘original’ philosopher. Scholars are rightly puzzled that Plotinus could actually think that some of the things he says are in fact authentically views shared by Plato. There are several reasons for this puzzlement. First, like the Middle Platonists, Plotinus does not limit his Platonic sources to the dialogues alone. Although the dialogues are primary, the Aristotelian testimony and the oral tradition are also taken to be relevant. Second, the fact that Plotinus represents himself as a defender of Platonism as well as an expositor of it means that he has to apply Platonic principles to the solution of problems that are outside the direct concern of fourth-century BCE philosophy. Third, in addressing problems about the construction of the material realm, Plotinus does not hesitate to apply Aristotelian arguments and distinctions. Plotinus evidently thinks that the employment of these is at least consistent with a Platonic framework, although this means that sometimes he gives the impression that he has detached himself from that framework. It is sometimes difficult, though by no means impossible, to reconnect his use of these distinctions both with claims made in the dialogues (Plato’s version of Platonism) and ultimately with UP. Finally, the very idea of a systematization of Plato’s thought may seem to be ipso facto distortive. To appreciate the case that this is not so, we need to see systematization both as arising out of UP and as underlying the positive arguments made in the dialogues. It is necessary to see systematization as inseparable from unification, that is, ‘reduction’ in some sense to a first principle of all.60 For example, the argument or arguments for the immortality of the soul in Phaedo are thought by Plotinus to rest upon a systematic expression of what UP entails, ultimately a unified doctrine of first principles. Plotinus’s implicit attribution to Plato of a systematic expression of UP is admittedly itself a sort of abductive inference. But this in itself is hardly a criticism of it.
The pejorative neologism ‘Neoplatonism,’ which has its origin in eighteenth-century German academic histories of ancient philosophy, cuts two ways.61 In supposing that the ‘Neoplatonism’ of Plotinus or of anyone after him is different from Plato’s philosophy, one necessarily supposes the obverse. That is, Plato’s philosophy must be viewed as containing none of the elements of Neoplatonism. This can mean one of two things. First, it can mean that specific doctrines found in Plotinus are absent from Plato’s philosophy. Just to take perhaps the most contentious example, it might be supposed that the positing of a first principle of all above ‘being’ is Neoplatonic and emphatically not Platonic. Accordingly, the Idea of the Good in Republic has to be interpreted in such a way that it does not fit this description. In addition, Aristotle’s testimony that Plato identified the Good with a first principle of all named ‘One’ has to be discounted. The justification for so doing is no doubt that the superordination of the Good and its identification with the One constitute deviations from Plato’s true philosophy. But then, of course, only one who has independent access to what this is can be in a position to make this claim. As we will see in the next chapter, the only apparent vehicle for independent access is the dialogues. But to employ some dialogues to interpret others already implies a criterion of relevance, say, developmental ordering or theoretical cogency. But this brings us once again into question-begging territory.
Perhaps more profoundly, setting Neoplatonism over against Platonism naturally leads to the supposition that the systematic nature of the former must be seen in contrast to the relatively unsystematic nature of the latter.62 Thus, some scholars arrive at a patently circular argument: Plato’s philosophy is unsystematic because Plotinus’s philosophy is systematic and innovative (i.e., un-Platonic).63 Perhaps the weakness in this argument will be evident merely by pointing out its circular nature. Nevertheless, there is still the positive case yet to be made, the case that Plotinus, and many others going back to the Old Academy itself, were neither innovating nor fantasizing when they set out Plato’s philosophy in a systematic format. The various systematic constructs out of UP, including Plato’s own, constitute Platonism.
1. See Brown 2012, 98–107, for a contemporary defense of what Brown calls Platonism in mathematics over against naturalism. Brown concentrates on the immaterial and eternal existence of “mathematical objects and facts.”
2. See Cicero, ND 1.73, where the interlocutor Velleius refers to a pupil of Plato as Platonicus. According to Glucker (1978, 206–25), philosophers began to call themselves ‘Platonists’ in the second century CE. Prior to that, disciples of Plato were typically called ‘Academics.’ This term poses a problem when used both of a ‘dogmatic’ follower of Plato, like Antiochus of Ascalon, and of the so-called Academic Skeptics. In what sense, if any, were the latter followers of Plato? See below. Glucker (ibid., 225) postulates as an explanation of the change from the use of the term Academici to Platonici in the second century the connotation of skepticism associated with the former during the last three centuries BCE.
3. Efforts to “connect the doxographical dots” between Xenocrates or Polemo and, say, Antiochus of Ascalon face an almost insurmountable wall of evidentiary silence. On the other hand, neither Philo of Alexandria, Plutarch of Chaeronea, nor Alcinous—all systematic Platonists in some sense—give the impression of being particularly original in their constructions of versions of Platonism. It is, in my opinion, difficult to maintain the view that Stoics and Academic Skeptics were the sole transmitters of Platonic doctrine to these admittedly rather distant disciples of Plato.
4. See, e.g., Gadamer (1985, 2:508), who declares bluntly: “Platon war kein Platoniker.” Dodds (1928, 129) sees in the failure to distinguish Platonism from Neoplatonism the source of multiple misunderstandings of the philosophy of Plotinus. Ryle (1966, 9–10) writes, “If Plato was anything of a philosopher, then he cannot have been merely a lifelong Platonist.” Ryle here takes a particularly narrow view of what Platonism is.
5. See, e.g., Press 2000, the subtitle of which is “Studies in Platonic Anonymity.” In the introduction to this collection of essays, Press provides a useful survey of various scholarly positions that take “Platonic anonymity” to be virtually equivalent in meaning to the “non-doctrinal” nature of the dialogues.
6. See Brittain 2011, 530–41, for a helpful survey of the traditional periodization of the history of Platonism.
7. Robin (1908) thinks that Aristotle’s testimony applies specifically to Plato’s philosophy after his writing Parmenides. Hence, Robin’s view is developmentalist.
8. See Robin 1908, 600: “Aristote nous a mis sur la voie d’une interprétation néoplatonicienne de la philosophie de son maître.” The conclusion is echoed by De Vogel 1953, 54: “The studies of the last generations concerning the sense of later Platonism, and especially of the doctrine of Ideal Numbers, has led us to the insight that Platonism must be understood in a Neoplatonic sense, and that Neoplatonism should be regarded, in its essence, as a legitimate Platonism.” For a complete repudiation of this conclusion, see Dörrie 1976, who argues that Platonism was reconstructed in a new phase after a break in the tradition more or less stretching 150 years from Cicero to Plutarch. Consequently, the rise of Neoplatonism really does constitute an innovation. Dörrie (45–47) sees the “rediscovery” of Plato’s Timaeus and the focus on its apparent creationism as crucial for providing a foundation for the innovation. Dörrie appears to give no weight to the Aristotelian testimony as providing the sought-for “bridge” between Plato and Neoplatonism.
9. This is the thesis argued for in Gerson 2005. Among later Platonists, Aristotle’s preeminence in matters of natural philosophy was recognized even though he contradicts Plato on numerous points. Therein is to be found an important clue as to how these Platonists thought of the nature of Platonism.
10. D.L. 3.25, says that “since Plato was the first to attack nearly all of his predecessors, one wonders why he did not mention Democritus.” In the subsequent chapter on Democritus (9.36), Diogenes quotes Democritus as saying that “I came to Athens and no one knew me.” At 9.40, however, Diogenes, relying on an account of Aristoxenus, says that Plato did in fact know of the works of Democritus but was unwilling to controvert him in writing owing to Democritus’s eminence. Herrmann 2005 argues that Democritus does appear—anonymously—in Plato’s Timaeus, particularly as a representative of those who think that necessity (a’νάγκη) governs all change. Herrmann (2007, 239–43 and 332–34, n. 467) adds an argument that Phd. 95E–105E is responding to an (unidentified) account of causality in Democritus and to the older philosopher’s use of the term ,ὶδέα. If Herrmann is right, then virtually all of Plato’s illustrious predecessors do in fact make appearances in the dialogues, even if some do so anonymously. See Magrin 2010, who shows that Plotinus’s analysis of the nature of the receptacle in Plato’s Timaeus and of its relation to cognition assumes that Plato is using Democritus as a foil in that dialogue. See also Morel 2002. Hussey (2012, 36) presents a suggestive argument that Aristotle initially undervalued the work of the Atomists himself and came only in his later works to see the full force of the Atomist position. If this is the case, it is not implausible that Plato, too, underrated the Atomists.
11. In Tht. 183E, Socrates declines to criticize Parmenides’ claim that all change is unreal after criticizing extreme Heracliteanism. The criticism of Parmenides is taken up again in Soph. 244B–245E, which, though not directly a criticism of the claim that change is unreal, is a criticism of the claim that “all is one,” which would, it seems, have as a consequence that change is unreal.
12. D.L. 1.20, says the term αἴρεσις (“sect” or “school of thought”) is used for those “who in their attitude towards appearance (τὸ ϕαινὀμενον) follow or seem to follow some principle.” He adds that the term is also used for “a bias (πρὀσκλισιν) in favor of coherent positive doctrines.” Diogenes refers to the earlier historian Hippobotus who lists nine αἱρέσεις including the Old Academy. What I am calling UP may be understood in this context as a proto-αἴρεσις. The “unity” of the Old Academy (and those who came after) is a unity of a proto-αἴρεσις. I thereby leave room to account for the specific differences among individual philosophers despite this unity. See Glucker 1978, 166–92, on the uses of the term αἴρεσις in antiquity.
13. See esp. Soph. 246A–248A; Lg. 891C1–4. Cornford (1934, 231–32) thinks that when Plato is criticizing materialists in Sophist, he means to include Atomists, who are nowhere explicitly named in the dialogues. I agree with Cornford that it is unlikely that Plato did not know about Democritus and Leucippus or that their materialism is not implicitly rejected in the Sophist passage.
14. Plato in Phaedo seems to hold that Anaxagoras tried to be an antimechanist but failed because he was a materialist. The “simple hypothesis” of Socrates in response to Anaxagoras (99D4–100A3) is an especially clear example of the beginning of an effort to construct the positive response that is based on UP. It combines all the elements of UP including, implicitly, antirelativism.
15. It is a version of the causal closure principle that is implicitly rejected at Tim. 47E–48B, where it is νõυς that overrules ἀνάγκη in the generation of the cosmos. I take it that Stoic incorporeals, namely, place, void, time, and sayables, precisely because they do not causally interact with anything, do not provide a means of separating materialism and mechanism. See Cicero, Acad. 1.39 (= SVF 1.90); Sextus, M. 8.263 (= SVF 2.363); Cleomedes (= SVF 2.541) on how the positing of incorporeals by the Stoics does not undermine causal closure. For the most explicit statement of the Stoic causal closure principle, see Stobaeus 1.138.14–139.4 (= SVF 1.89 and 2.336): ἀδύνατον δ, ε,ῖναι τὸ μὲν αἵτιον παρεῖναι, οὗ δέ ἐστιν αἵτιον μὴ ὑπάρχειν (it is impossible for the cause to be present and that of which it is the cause not to exist) (1.138.15–16). Here, of course, τὸ αἵτιον refers exclusively to material or corporeal efficient cause or causes. Cf. Alexander of Aphrodisias, De fato 22.191.30–192.8; 21–24. Seneca, Ep. 65.11, includes time and place as necessary conditions for causal interaction, criticizing Platonists for not including these. See Plato, Phd. 99A–B. Seneca does not think these necessary conditions are real causes, but he thinks that Platonists in their expansive understanding of causality should include them. Sedley (1993, 317) argues that “the Stoic causal nexus, far from being mechanical, exhibits to a quite astonishing degree the meticulous workings of an intelligent teleology.” Similarly, Bobzien (1998a, 48) finds in Chrysippus’s account of determinism “an element of teleology, rationality, organization, and order,” though she goes on to argue (53–56) for the “combination” of the teleological and mechanistic aspects of Stoic determinism.
16. Thus, the acceptance of the existence of immaterial entities strengthens the challenge to the causal closure principle.
17. As I will explain at greater length below, I take the Eleatic monism in Parm. 127D–128D as the central target of Plato’s antinominalism. The target is absolutely clear since Eleaticism is unqualified nominalism—not even two things can exist if from this it follows that they will be the same in each being one. Antisthenes may also be a target. See Soph. 251A–C. See Allen 1983, 79–80 on Eleaticism as a form of nominalism.
18. The rejection of nominalism presupposes the falsity of extreme Heracliteanism. If everything were always in flux in every way, things could not have properties. I do not, however, list the rejection of extreme Heracliteanism as one of the central elements of UP because Plato agrees that sensibles are in some sense always becoming if not becoming in all ways. To be able to show that an account of sameness in difference is possible is, along with the evidence of the senses, sufficient to remove any reasonable motivation for extreme Heracliteanism.
19. We learn from Sextus Empiricus, M. 7.60 (cf. Plato, Tht. 161C3) that this claim comes from Protagoras’s book On Truth.
20. The so-called Recollection Argument in Phd.72E3–78B3 provides a sort of transcendental argument against skepticism, showing that certain cognitive acts in which we manifestly engage would not be possible if we did not already possess ἐπιστήμη. I take Theaetetus, despite its aporetic conclusion, to attempt to provide the necessary foundation for an adequate response to the skeptic. That response begins, naturally enough from a Platonic perspective, with an account of what ἐπιστήμη is.
21. Phdr. 259E–274B is a particularly vivid and wide-ranging attack on those who disregard knowledge in the practice of their craft. As we learn from 272D2–273A1, the pursuit of ‘the likely’ (τὸ εἰκὀς) is not an acceptable substitute for the pursuit of knowledge.
22. At Tht. 186A–E the refutation of Protagorean relativism and hence of the thesis that knowledge is sense perception turns on showing that the possibility of knowledge—that is, cognition of what is objectively—entails the falsity of relativism, the view that what is is reducible to what is for one person or another. Thus, relativism makes knowledge impossible.
23. See Tim. 51B–E where the proof of the falsity of materialism goes like this: if νοῦς (intellection or knowledge) is different from true belief, then Forms must exist. But if Forms exist, then materialism is false.
24. Atomism is not really an exception to this, since the reduction of all phenomena to atoms and the void is far more important than the fact that the atoms are infinite in number. See Krämer 1969, 15–18 and 1994, 5–6, who argues that Plato’s doctrine of first principles is exclusively the result of his encounter with Eleaticism, and is not a product of general Pre-Socratic reductionism. This seems to me to be implausibly narrow.
25. Cherniss (1936, 456) thinks that the theory of Forms itself provides the requisite unification: “That the necessary and sufficient hypothesis for this sphere [the sensible world] turns out to be the very one needed for ethics and epistemology makes it possible to consider the three spheres of existence, cognition, and value as phases of a single unified cosmos.” It is historically implausible in the extreme that any Platonist supposed that the cosmos was “unified” by a multiplicity of Forms. See, contra Cherniss, Krämer 1964b, 85–88.
26. See Brown (2012, chap. 2, “What Is Naturalism?”), who, in the course of an argument for Platonism, understood very roughly along the lines of UP, characterizes naturalism as the position holding that “all facts are natural facts and only natural science can discover and explain them.” For Brown, the existence of eternal mathematical truths is the key premise in the argument rejecting naturalism. As Brown goes on to point out (94), “the principal objection to Platonism is epistemic.” That is, the denial that ἐπιστήμη, as defined by Plato, is possible. As we will see at various points in this book, part of the reason for the centrality of antiskepticism in the development of versions of Platonism is that the assertion of the possibility of ἐπιστήμη ties together the other elements of UP as does no other.
27. See Kretzmann, 1997, 23–27.
28. The early Stoa represents, in part, an attempt to retain antirelativism and antiskepticism while abandoning the other elements of UP. Later Platonists rejected such an attempt. Thus, Stoics might well make true claims in ethics following from their antirelativism, but the antirelativism was taken to be arbitrary without a consistent metaphysical framework, including antimaterialism, antimechanism, and antinominalism. Porphyry, in his Life of Plotinus (14.4), says that “Stoic and Peripatetic doctrines are blended into his writings, though they are not obvious” (’Eμμέμικται δ, ἐν τοῖς συγγράμμασι καὶ τὰ Στωικὰ λανθάνοντα δὀγματα καὶ τὰ Περιπατητικά). Plotinus, however, also rejects many Stoic doctrines because they rest on false principles, especially materialism.
29. See Merlan 1953, 166–77 on the evidence for such hierarchy in Plato, Aristotle, Academics, and later Platonists. Halfwassen (2002b) argues that the very idea of metaphysics as an explanatory science is, according to Plato and all Platonists, based on the necessity of positing an absolutely simple first principle of all. Cf. Reale 1997, 95–107, who finds in Phd. 96A–102A “the Magna Carta of Western metaphysics.”
30. Heraclitus or Cratylus would seem to deny that the objects of knowledge must be stable. The Platonist’s claim that the objects of knowledge cannot be unstable is as much a claim about what the ne plus ultra of cognition must be as it is a claim about the nature of the objects of such cognition.
31. At Soph. 247B–C, the ‘reformed materialists’ are said to allow that justice or wisdom, for example, exist and that it is not reasonable to say that they are bodies. But their concession need not be taken to constitute their abandonment of materialism as I have defined it. For these might be properties of bodies or supervenient on bodily states or dispositions of bodies functionally related to them. The ‘hard-line materialists’ at 247C–E would be, we are told, inclined to accept the proffered principle of being: whatever has the power (δύναμις) to affect or to be affected in any degree, by the most insignificant agent, even once. These hardliners could accept the existence of justice and wisdom and so on if their ability to affect anything is taken as a corporeal power. This is apparently the Stoic position, perhaps responding to this passage of the dialogue. See Brunschwig 1994, 119–22. Contra Brunschwig, Vogt (2009, 143–45) denies that the Stoics held that being is power; rather, power is taken as a property of bodies. The question “What is being?” is, according to Vogt, not even on the Stoic agenda. I tend to agree with Vogt that speaking of ‘Stoic metaphysics’ is at best misleading unless, of course, we grant that ‘metaphysics’ can refer not to a science of being but to the study of ultimate principles and causes. It is the inseparability of the question “What is being?” and the search for ultimate causes and principles that characterizes Platonism.
32. I will discuss Platonism’s distinction between truth as an ontological property and a semantic property below.
33. See, e.g., Boys-Stones 2001, chap. 6, esp. 99–105. He argues (102) that “the particular doctrines held by particular Platonists are (obviously related, but actually) incidental to what they were: I want to argue that they held the doctrines they held because they were Platonists rather than vice versa. And Platonism at root seems to me to be this: the belief that Plato’s philosophy was dogmatic and authoritative. Everything else follows from that.” Brittain (2011, 527) thinks that the ‘Platonic tradition’ has three essential characteristics: (a) a belief in the authoritative status of Plato’s work; (b) a shared set of assumptions about the inadequacy of empirical experience for understanding the world; and (c) an increasing interest in a range of religious practices.
34. Aristotle, Meta. A 6, 987a29–31, says that Plato followed (a,κολουθοῦσα) the Pythagoreans “in many ways,” though his philosophy also had distinctive features (ἵδια). Aristotle adds that these distinctive features arose under the influence of Heraclitus, Cratylus, and Socrates.
35. See Hadot 2002, 64, writing of the “unity” of the Academy: “I think we can say that although Plato and the other teachers at the Academy disagreed on points of doctrine, they nevertheless accepted, to various degrees, the choice of the way or form of life which Plato had proposed.” I am not so sure, though, about the causal connection between this way of life and the positive construct out of UP, that is, which one is prior.
36. See Rep. 509D–510A.
37. Rep. 510B–E.
38. Cf. 534A3–5 where διάνοια is said to be analogous to εἰκασία, the mode of cognition that is named at 511E2 as that which has as objects the images in water, etc.
39. See Aristotle, Meta. A 6, 987b14–18. Cf. Z 2, 1028b18–21. Since these Intermediaries are not explicitly mentioned in the dialogues (but see Rep. 525E–526A, 534A), these passages seem to be a clear case of Aristotle assuming that Platonism is only accidentally, as it were, contained in the written works. For the later Platonic position, see, e.g., Syrianus, In Meta. 82.20; Proclus, In Parm. 1057.20–25; In Euc. Elem. 4.18, 11.5–7. Though the matter is controversial, the weight of scholarship since Adam (1902, 2:68, 161–63) has been in support of Aristotle’s interpretation. See most recently Denyer 2007; Miller 2007, 318–28; and Franklin 2012.
40. Tim. 29E1–3: ἀγαθός ἧν, ἀγαθῷ δὲ οὺδεὶς περὶ οὺδενός οὺδέποτε ἐγγίγνεται ϕθὀνος. τούτου δ, ἐκτὸς ὣν πάντα ὄτι μάλιστα ἐβουλήθη γενέσθαι παραπλήσια έαυτῷ. Cf. Aristotle, Meta. A 2, 983a2–3, on the ungrudgingness of the divine.
41. Tim. 30D1–31A1: τῷ γάρ τῶν νοουμένων καλλίστῳ καὶ κατὰ πάντα τελέῳ μάλιστα αὺτὸν ὁ θεός ὁμοιῶσαι βουληθεὶς ζῷον ἕν ὁρατὀν, πάνθ, ὄσα αὺτοῦ κατὰ ϕύσιν συγγενῆ ζῷα ἐντὸς ἔχον ἐαυτοῦ, συνέστησε.
42. Also, at 37A1–2 we learn that the body of the universe was brought into being by “the best of things intelligible and eternal” (τῶν νοητῶν ἀεί τε ὄντων ὑπό τοῦ ἀρίστου), namely, the Demiurge.
43. See Proclus, In Parm. 630.15ff; 1083.1–1088.3.
44. See Enn. III 4, 5.4ff. At IV 4, 22.10–12, Plotinus actually complains that Plato’s looseness in language exacerbates and certainly does not alleviate the problem being considered, which is in this passage the sense in which the earth may be said to have a soul.
45. See Soph. 248A–249D, where the position of the ‘friends of the Forms’ is rejected whoever these ‘friends’ may be.
46. Although Aristotle’s commitment to the possibility of a universal scientific about natural kinds is sufficient to class him as an antinominalist, any suggestion that this characterization is anachronistic should be dispelled by his dismissal of Antisthenes’ claim that nothing could be used to refer to something other than its own formula (οἰκεῖος λὀγος). See Meta. Δ 29, 1024b32–33. If, as Aristotle believes, terms other than a thing’s own formula can be used to refer to it, then that thing can have properties that do not identify it unqualifiedly and so can be the same as the properties of other things.
47. See EN A 6.
48. See Meta. Λ 10, 1075a11–13: ’Eπισκεπτεὀν δὲ καὶ ποτέρως ἔχει ἡ τοῦ ὅλου ϕύσις τὸ ἀγαθόν καὶ τὸ ἄριστον, πὀτερον κεχωρισμένον τι καὶ αὺτὸ καθ, αὑτὀ, ἣ τὴν τάξιν. ἣ ἀμϕοτέρως ὥσπερ στράτευμα; (We should examine in which of two ways the nature of the whole has the good, that is, the highest good, whether as something separate and itself by itself or as the order of the whole; or does it have it in both ways, like an army?) Aristotle’s answer is the latter. So the highest good, that which is ‘itself by itself’ in the familiar Platonic language, is separate. The response to this that maintains that Aristotle’s and Plato’s positions on the highest good are essentially different is superficial. They are in fact variations based on shared principles with the same systematic explanatory goal.
49. When Plato in Republic hypothesizes the Good as an unhypothetical principle (510B7), he is clearly using the term ‘hypothetical’ in two ways: in the first, he is making an abductive inference; in the second, he is claiming that this inference is to a self-explicable or autoexplicable first principle. So, too, Aristotle’s Unmoved Mover may be accurately described as a hypothesized unhypothetical first principle of all.
50. See D.L. 4.28–67.
51. As Sedley (1996, 98–99) points out, at least one Platonist in antiquity, the author of the anonymous Commentary on Plato’s Theaetetus, argued that Socratic ignorance was methodological, that is, it was a position assumed for “dialectical or didactic purposes.” Socrates is made to assume a sort of principled ignorance, so that he could get his interlocutors to strive to arrive at the correct answers themselves. A related and obvious point, not mentioned by Sedley, is that if this interpretation is correct, it is Plato who makes Socrates methodologically ignorant, presumably based on an antecedent doctrine about knowledge and how it is achieved. This interpretation was standard among later Platonists. Cf. Proclus, In Alc. 170.28–171.6; Olympiodorus, In Alc. 12.12–14; anonymous Prolegomena to Plato’s Philosophy 10.57–72.
52. Vogt (2012, 189) offers a Pyrrhonian Skeptic “reading” of Socratic ignorance as the exercise of caution in formulating beliefs. Such laudable caution, however, does not prevent Socrates from acting on the beliefs he arrives at after argument, including, for example, his belief in Crito that he should remain in prison.
53. See Phd. 66E4–67B2.
54. Phd. 72E3–77A5.
55. Tht. 197B–D.
56. See Tim. 29D2, 68D2, ἐικός μῦθος.
57. See Meta. A 6, 987a32–b1. I am aware of no parallel text in which the words ἐκ νεὀυ are used to refer to “early works” or “things written when young,” or something like that. They seem always to be used, by Aristotle and others, to refer to the early stage of the life of a human being or animal or plant.
58. See Meta. N 4, 1078b30–1079a4 (mainly repeating the historical observations made at Α9, 990a34–990b9), where Aristotle says that Socrates did not posit Forms as separate (χωριστά), the implication from the context of this discussion being that Plato (and others) did. I take the unspecific reference to those who separated the Forms to encompass a variety of views regarding what was no doubt an unsettled matter in the Academy. However, at Meta. Δ11, 1019a1–4 Aristotle says that the meaning of ‘prior’ by nature and essence (κατὰ ϕύσιν καὶ οὺσίαν) originates with Plato. If A is prior by nature and essence to B, then A can exist without B, but not vice versa. I take it that this is what Aristotle means when he attributes the separation of Forms to Plato. See Λ1, 1069a34 with Z 2, 1028b19.
59. See Proclus, PT 1.1.16ff. On Plato as unquestioned authority for Plotinus, see Krämer 1964a, 292; Armstrong 1970, 213–14. By contrast, Dodds (1960, 2) thought that for Plotinus Plato’s authority was mainly decorative, not substantial. Dodds says, “Formally, but only formally, the philosophy of Plotinus is an interpretation of Plato; substantially, I should call it an attempt to solve the spiritual problems of his own day in terms of traditional Greek rationalism.” Both positions in my view fail to adequately distinguish the ‘level’ at which Plotinus is in complete accord with Plato, that is, UP, despite divergences in detail.
60. It is precisely for this reason that I resist the efforts of many scholars to locate the systematization of Plato’s philosophy no earlier than in the early imperial period. See, e.g., Dörrie 1976; Bonazzi and Opsomer 2009, 1; Donini 2011; Ferrari 2012. Opsomer (2005c, 164–75), however, argues that Plutarch was committed to the ‘unity of the Academy’ thesis, a unity of doctrine from Plato onward, including the Academic Skeptics. In positing an unhypothetical first principle of all, Plato announces the systematic project. Aristotle’s testimony only confirms this.
61. See Büsching 1772, 2:471ff., who uses the term to describe what is in comparison with the philosophy of Plato “eine unklare mystische Schwärmerei.” Although the term ‘Neuplatonismus’ belongs to the latter part of the eighteenth century, the wholly negative judgments on the fidelity of Neoplatonists to Plato is at least a generation earlier. See Brucker 1742, cited in Tigerstedt 1974, 58, 100–101, nn. 437 and 452. Tigerstedt quotes Brucker as claiming that “they are all—from Plotinus to Proclus and Olympiodorus—madmen, liars, imposters, vain and foolish forgers of a most detestable and false philosophy.” Instead of ‘Neoplatonists,’ he calls them ‘pseudo-Platonists’ and proponents of ‘syncretism.’ Dörrie (1976, 45) follows this tradition closely, especially in his insouciance regarding Aristotle’s testimony. He concludes his examination of Platonism after Plato by saying, “Den eigentlichen Aufbruch in eine Ontologie, die alle Anschaulichkeit abstreifte, vollzog erst Plotin.” See Szlezák 2010a for an illuminating sketch of the course of Platonic hermeneutics from Brucker to Schleiermacher.
62. See Krämer 1964b, 69 on the contrast between the systematic interpretation of Platonism from Aristotle onward and modern and contemporary efforts to jettison systematization altogether.
63. See Tigerstedt 1974, 6, who quotes Wilamowitz as declaring that Schleiermacher had discovered the real Plato and had thereby put an end to the ‘Neoplatonic Plato.’