Chapter 2. Plato’s Concession to the Practical Arts in the Phaedrus

One of the most important threads running through the intellectual history of the fifth and fourth centuries was the multidisciplinary attack on the question of what kind of art or science could hope to master the complexities of human experience. This was a question of theology, of history, of physiology, of politics, of rhetoric, and of ethics. The practitioners and theorizers of the arts contended to show that they could reduce the myriad factors governing practical outcomes to some kind of reasoned order, and that they relied on a foundation of critically scrutinized general principles—knowledge of what was knowable.

Plato confidently asserted that the rational investigation of the truth—defined in opposition to the unreasoned beliefs and knacks on which the tekhnai relied—was the proper foundation for virtue and (as we read in the Phaedrus) for proper rhetoric. Yet, on the basis of the previous chapter’s Aristotle–Isocrates comparison, we can see more clearly that Plato was completely and acutely aware of the rival claims of the practical and empirical arts, finding himself forced to use their terms and take a position in their internal debates. Thus Socrates in the Phaedrus tells orators to think like physicians—in particular, like the “Hippocrates” who founded all medicine on a complete and systematic theory of nature, or in other words a rationalist who turned out the kind of Presocratically flavored speculations we find in the treatise Regimen. [1] Yet he cannot have been unaware of the sophistication with which a rival text like On Ancient Medicine defended the superiority of a medical science, and a practice of medical treatment, based on the same complex of experience, imprecise knowledge, and so on, that we have been discussing. Some of the methodological similarities between On Ancient Medicine, Isocrates, and Aristotle have been previously adumbrated [2] ; what I would like to emphasize is that the empiricist physicians had worked out no less a “conception of medicine as a systematic body of knowledge.” [3] We are forced to recognize that Plato deliberately caricatures and silences the vigorous ongoing discussion of how the tekhnai can be made adequate to the reality of praxis and described adequately by and for the truly intelligent practitioner. He must ally himself with one school of medicine over another, when an informed reader would know that the caricatured physicians equaled Socrates’ “Hippocrates” in scientific spirit and methodological seriousness. [4] It can be no accident that it is against rhetoric that Plato deploys this sleight of hand.

Plato aspired to exalt the empery of accountable knowledge and reason but strictly maintained the distinction between the practical arts and his own philosophical enterprise. In light of this tendency, the Phaedrus has long interested Plato’s readers for the seriousness of its engagement with the rival art of rhetoric, for in the Phaedrus we learn that persuasive rhetoric can indeed be a proper art or tekhnē, something better than the artless empeiria attacked in the Gorgias or the poetic technique without knowledge ridiculed in the Ion, and indeed something that, in this elevated form, is an inescapable part of philosophy. Readers who are sympathetic to the intellectual aspirations of rhetoric in its own right, or who are intrigued by the appearance that Plato is flirting in this dialogue with the illicit powers of Eros and rhetoric, will inevitably ask, upon learning that philosophy cannot be separated from “true” rhetoric: can philosophical rhetoric, in turn, be completely and convincingly disentangled from “popular” rhetoric?

While the dialogue certainly means to hold the line between the two, it equally aims at a complicated picture of the relationship between them, so that there is still much to learn by studying the analogies and compromises by means of which Plato is able to claim rhetoric for philosophy. Rhetoric modified by an adjective is still rhetoric, and Plato has allied philosophy to a beast that lived in the outside world and had its own natural limits and capacities. A particularly instructive way to diagnose the effects of this is to examine the analogy of “Hippocratic” medicine adduced by Socrates for true rhetoric: The import of this analogy is not, we will see, that medicine had a unique and distinct kind of claim to scientific rationality (as the least “popular” of the arts, to use a term from the Phaedrus). Rather, for Plato’s contemporary audience, who would have been better informed than we are about the methodological debates of the practical arts, the medical analogy involved Socrates in a host of issues that applied in common to multiple practical arts, including rhetoric as well as medicine. It is largely “the result of chance” that the first general epistemological critique in our literary record (the Hippocratic Art) is medical and not rhetorical, and it can be difficult to determine which of the two disciplines pioneered a given line of attack on their shared problems. [5]

Within this context, the rationalist medical principles to which Socrates appeals are in constant dialogue with a more empiricist, but no less rigorous, strain of medical methodology that wants to achieve the very same goal as Socrates—a well-founded claim to reasoned systematicity—but to do so with greater confidence by taking into full account the challenges of harmonizing rational order with practical circumstances. In fact, as we will see, there is no such thing, whatever Plato may lead us to believe, as a purely empiricist medical methodology, and we may admire those Hippocratic authors who are the least inclined to attempt a tidy divorce between the two paths, having studied the attractions and limitations of both. “Knowledge” and “system” are not terms that divide the aspirations of one school from those of the other.

Not only is Socrates’ Hippocratic analogy constructed purely [6] in order to elucidate the proper principles and technique of rhetoric’s transactions with the soul, but the discipline of rhetoric itself was deeply involved in the same methodological dilemmas. To put it the other way around, medicine was rhetoric’s near neighbor and could serve as a useful analogy precisely because it had worked through some of the same questions of method. As I have argued in the previous chapter, Isocratean theory in particular was seeking to contribute to the reconciliation of theory and practice, an approach whose seriousness and philosophical potential is well shown by the fact that Aristotle recognizably takes it back up against Plato and develops it in the Nicomachean Ethics. Moreover, the Phaedrus itself shows signs of ironic awareness, on Socrates’ part, that the rationalist tendencies expressed in a work like the Hippocratic Regimen [7] do in fact run the danger of failing to manage the facts of the world as they concern the agent navigating the challenges of life. So not only does the dialogue’s analogy with the practical arts itself raise contradictions, but the more we flesh out the real-world nature of the models being invoked, the more we may also suspect that Plato himself is conscious of the compromises involved, determined to take them seriously and to confront the strengths and attractions of a very prestigious rival intellectual tradition.

The idea of a rhetorical tekhnē developed in the Phaedrus is not without its contradictions. It is philosophical and grounded in dialectical knowledge of the truth, and yet at the same time the dialogue’s argument repeatedly admires its purely practical advantages over unphilosophical rhetoric and recognizes that it is and must be an art suited to use in real circumstances. We could explain these two sides of Socrates’ true rhetoric by crediting him with an original synthesis of empirical technique and scientific purity, but a closer look at rhetorical and medical writers suggests that it is simpler to see a basis for both sides in the internal debates of the tekhnē-practitioners, who on their own were busy trying to reconcile the same two approaches to a sound method.

Rather than acknowledging that rhetoric as generally encountered is a tekhnē with all that entails, so that philosophical rhetoric is distinguished by being not merely an art but something more, [8] Socrates takes the opposite approach and argues that a foundation in true knowledge is a requisite for every art, so that rhetoricians working without such a foundation are practicing an atekhnos tribē (260de). It is important to note that when Socrates allows rhetoric to speak in her own defense, rhetoric does not defend the idea of a tekhnē that requires no knowledge, as we might expect from the conventional interpretation of passages in Isocrates that seem to say that the orator relies on doxai (notions, opinions, judgments) and not on epistēmē (knowledge). [9] Rather, rhetoric insists that knowledge of the truth is an expected prerequisite for speaking and persuading in accordance with the art of rhetoric: While introducing uncertainty about rhetoric’s status as a tekhnē, Socrates nonetheless considers that rhetoric’s defense may be satisfactory and admits that the better sort of existing rhetoric could have pretensions quite near to those he will advance for true rhetoric: not that it is an epistēmē, but that it depends on sound knowledge as a preliminary.

Within this broad similarity, we can recognize the role Isocrates assigned to epistēmē in his system of oratorical education, but only if we first recover his discussion of knowledge from the obscurity in which it has lain. What has covered over the importance of knowledge in Isocratean education is the fact that Isocrates has more impressively stressed its limitations—that it cannot precisely and effectively master the onrush of circumstances in which the orator must decide and speak. Never mind that Aristotle felt the need to stress these same limitations for the purpose of laying out a theoretical and practical basis for the virtuous actor in the Nicomachean Ethics: these passages are nonetheless the first reached for to demonstrate the gulf separating Isocrates from the philosophical way of conceiving things. While we must and will admit the shortcomings, from a Platonic point of view, of the role knowledge plays in Isocrates’ system, we must first study that role positively.

In Against the Sophists 16, [10] in which Isocrates polemizes against “sophists” who share many points in common with the sophistical and rhetorical opponents we meet in Plato, Isocrates insists on the achievability of knowledge in education: In this emphatic assertion (βούλομαι … ἔτι σαφέστερον εἰπεῖν … φημὶ γὰρ ἐγὼ …), Isocrates specifies the object of rhetorical knowledge as the “forms” (ideai) used in composition. Moreover, he insists that to gain such knowledge we must put ourselves in the hands not of the charlatans with their boastful promises, but of those who already possess some knowledge in this area (tois eidosi ti peri autōn).

The programmatic importance of this passage is confirmed by the fact that Isocrates quotes it some thirty or forty years later at Antidosis 194, where it serves as evidence that no one has spoken so consistently or with greater truth and justice about philosophia than he (195). Here Isocrates’ larger point is to take to task those critics—perhaps not very unlike Plato—who deny his pursuit the status of a tekhnē in the first place (202) but gloss over the uniform and consistent results of his education for all his students (203–206). These naysayers shallowly criticize the art if it does not quickly and easily transform its students (199f.), when in fact its results are to be appreciated (207) as testimony to the power of sustained effort (epimeleia) to effect a change in the quality of the intellect (to phronein, phronēsis). All of this, Isocrates says, is just as his critics know happen in the tekhnai whose precision they recognize: our areas of knowledge are won only with hard work (μόλις μὲν ἡμῖν τὰς ἐπιστήμας παραγιγνομένας, 201).

To return to Against the Sophists 16, then, we seem to find a definite if limited kind of important knowledge within Isocratean education. We will consider shortly Isocrates’ further indications of what these teachable and knowable ideai are. For now let us anticipate some of the objections to taking them seriously. [11] It helps to notice what I have already tried to suggest, which is that Isocrates brings out this claim as a crucial and distinctive feature of how he conceives the proper configuration of the basic factors of nature, diligence, and education (paideusis). [12] The passage concerning the ideai confirms that this is Isocrates’ version of an already traditional triad of factors—nature, practice, and knowledge—whose history and influence have long been appreciated. [13] Socrates accepts the applicability of this same triad in Phaedrus 269d when he begins with the general principle that a tekhnē of rhetoric (qua tekhnē, the passage seems to imply) will be mastered if a student with natural rhetorical ability adds knowledge and practice: Isocrates’ expression describing the value of the knowable ideai (ἐξ ὧν τοὺς λόγους ἅπαντας καὶ λέγομεν και συντίθεμεν) could denote anything from a very mechanical to a very sophisticated process of applying knowledge in preparation and performance. [15] We should remember both the sweepingly powerful definition Isocrates gives to logoi, and also that the conclusion of Socrates and Phaedrus’ discussion of the artless features of Lysias’ speech (atekhna, 262c6) focuses on its lack of principles of rational and organic construction (264b3–c5). [16] Even if we apply a fairly technical and limited definition of Isocrates’ ideai, it seems plausible that in this passage and others Isocrates is laying claim to a more organized compositional process that can defend itself at least against the charge of this particular kind of atekhnia. [17] In short, we are not entitled to be as surprised and skeptical as many would be when faced with the statement of Sextus Empiricus (Adversus rhetoras 62), who in a survey of various definitions of rhetoric notes that, whereas one Athenaeus defines it more conventionally as logōn dunamis, [18] “Isocrates asserts that the practice and pursuit of orators is no other thing than the knowledge or science [epistēmē] of persuasion.” [19]

The more completely we review the statements in Isocrates and in the Phaedrus about the content and purpose of the knowledge with which the ideal orator works, the more we see that, despite the differences between the theoretical foundations of the two models, there are several common points of emphasis. In Socrates’ construction, the orator’s knowledge of the subject matter and of the hearer’s soul allows him to adapt his speech accordingly. [20] At 271b1–5, thanks to the dialectical art of thinking, which works through division, anyone who offers a serious rhetorical tekhnē will have classified the “kinds,” or genē, of logoi: This half of the equation is quite reminiscent of Isocrates’ ideai, which in the same passage as above he too calls the eidē of logoi:

A closely parallel passage, Isocrates Helen 11, may lead us to take the intellectual level of the Isocratean ideai more seriously, since they are not always simple to learn but in the case of logoi “of general import and credibility” (koinoi kai pistoi, trans. Mirhady and Too 2000) are apparently hard to learn, as are the kairoi, and Isocrates particularly stresses the correspondingly increased difficulty of “matching” (sunthesis) the logoi with the use-circumstances, or kairoi.

Isocrates’ emphasis on knowledge of kinds, applied in use, fits in nicely with the surprisingly practical orientation of much of the Phaedrus’s discussion of tekhnē-worthy, or “philosophical,” rhetoric. The word khrēseis itself follows on the discussion of eidē in Plato (271c10–e2), just as it does in Isocrates, and the application of aisthēsis in this passage should be compared to the role played by doxai in Isocrates. It must have struck many readers of the Phaedrus that, despite true rhetoric’s lofty pretensions, Socrates also promises that the knowledgeable possessor of a tekhnē will be more effective at deception (262b) and in general dwells on the persuasive power of the true orator (cf. 271b ff.), so much so that the reference to his involvement with “the truth about just or good things” (272d4–5) almost comes as a surprise. Isocrates, in contrast, perhaps more defensive about distinguishing himself from the unprincipled sophist, in the passage of the Antidosis introducing his defense of his “philosophy” as a tekhnē of painstaking intellectual self-cultivation, squarely aims this defense against impatient and shallow critics who believe oratory must consist of “deception and cheating” (199).

A deeper connection between Isocratean rhetoric and the Phaedrus’s true rhetoric is that they each must be flexible and are completely incompatible with the kind of fixed and specific prescriptions for action offered by the handbook-writers. This arises from the fact we have been studying, that they are both meant to be used in the complex circumstances of the real world. Though both are known to us for their writings, Isocrates and Plato are equally insistent about the inadequacy of written instruction. In Against the Sophists 12f., [21] shortly after having deplored some teachers’ claim that the epistēmē of logoi can be imparted in the same way as that of mere grammata (10), [22] Isocrates rejects the handbook-writers’ regimentation of tekhnē: he complains it cannot possibly do justice to the art of oratory, a “creative affair” in which a truly skilled speaker (tekhnikōtatos, 12) produces logoi that “partake of the circumstances of the moment [kairoi].” This brings to mind at once, in general, the Phaedrus’s critique of written discourse, as at 275c:

But the specific terms in which the Phaedrus speaks of the “use” phase of rhetoric should also be compared to Isocrates. For example, terminology of an Isocratean flavor occurs at Phaedrus 272a, where again the discussion is of how the relevant kinds of preparatory knowledge are actually tested in the crucible of real and present circumstances: Socrates uses the kairos terms favored by Isocrates three times in close succession, [23] clearly talks about how the speaker will apply the kinds of effects any interpreter would include among the Isocratean ideai, and very significantly finds in this performative culmination of the student’s training the decisive proof that “the tekhnē is well and completely produced” in him. [24]

The language with which Plato speaks of the complete assembly of the prerequisites for artful oratory must have been very current in the circles of rhetorical theory, for we see by now a set of echoes that can be extended: This last example pushes the pattern back into the fifth century, confirming that the Isocratean language that we can show was topical for Plato and Aristotle has its roots in the earlier rhetorical and tekhnē tradition.

Isocrates brings together prior education and the unpredictable circumstances of the kairoi in a comparable way in Antidosis 184. First the teachers have “examined the subject minutely” (diakribōsantes) and the students have learned (emathon). On this basis the students “string together” (suneirein) individual elements with an aim to bringing their doxai in closer accord with the kairoi. What follows are several statements often quoted to show Isocrates’ enmity towards epistēmē—the circumstances of the moment will elude the students’ epistēmai; the leap from training to performance cannot be learned by knowledge (eidenai); there is no epistēmē that can make a performance-level orator out of just anyone—but this obscures the importance of knowledge in Isocrates’ system and the extent to which Isocrates’ doxai are simply a way of talking about the kairoi which Plato also must address. Plato does not, as far as I am aware, claim that the kairoi are handled strictly through definition, division, and dialectic. It is also salutary to recall that Isocrates insists on the worth of his education for the student whose talents are not adequate for him ever to enter the arena of political oratory; such a student’s education is necessarily dominated by the content of the learnable knowledge (cf. 201).

So when we return again to Isocrates’ most famous statement on the limitations of knowledge, Antidosis 271, we can be more confident that it is proper to stress the qualifications: our nature cannot attain knowledge “that would enable us to know what we must say or do,” so that a premium remains on those who are able to form the doxai that actually necessarily operate when we stand on the field of action. The words may not have sat so comfortably in Plato’s mouth, but we also recognize that Plato shares Isocrates’ disdain for the handbook-writers who would presume to prescribe our words and actions with minute particularity, and must also make room for new factors to operate if the insights won through dialectic are going to be brought to bear in performance through the rhetorical tekhnē.

Isocrates’ Antidosis, composed in his eighties as a defense of his career before a fictional Athenian jury, notably introduces its long review of the author’s educational philosophy with an appeal to the jurors that they apply the standard of knowledge and not mere doxa: Ober has pointed out the Platonic and Socratic overtones of this. [26]

To sum up what we have said so far, while Isocrates did not profess Platonic dialectic as the art of thinking upon which the art of speaking must be based, he holds in common with Plato an interest in a foundation of knowledge upon which the less precisely controllable workings of discursive performance rely. Moreover, we should not accept unquestioningly Socrates’ more-or-less undefended notion that the method of definition and division is in fact a reliable foundation for any species of rhetoric. Is it not possible that rhetoricians such as Isocrates, and practitioners of the other arts, had considered different candidates for the sort of knowledge from which to begin, before deciding which was of most essential value for consistently producing good outcomes on a sound basis? Isocrates was certainly well aware of the rival view that rhetorical students should spend more of their time on pursuits like geometry: indeed, he endorses a certain amount of this and proclaims himself a lover of wisdom who teaches care of the soul and so forth because he appreciates and flirts with the prestige of the philosophical way, and yet rejects the extreme explicitly as “useless.” [27] Socrates’ example of beginning with a definition and analysis of love (263de) makes sense, but Isocrates’ ideai may also represent a kind of analytics. If Isocrates tends more to emphasize the limitations of knowledge, does this not inject some healthy Socratic skepticism into the discussion of whether we can indeed get to knowledge on the kinds of subjects on which we must speak? Are we allowed to act and persuade while our attainment of knowledge is still imperfect? It is difficult to have rhetoric at all if the answer is no.

When Socrates praises Isocrates at the end of the Phaedrus, we can suspect a serious aspect to it. I also suggest that we give due attention to the close literary similarity (unremarked, I believe) between the prophetic praise of Isocrates here, and the way Socrates and Theodorus speak about Theaetetus’ potential in the Theaetetus. In that undoubtedly sincere tribute to Theaetetus’ noble generosity, temperament, and intellect, Socrates’ sums up Theodorus’ just praise by saying, “You say that the man is gennikos” (144d5). This word is used elsewhere by Plato only in Phaedrus 279a4 (the praise of Isocrates), and it is a “rare and insistent doublet” of the more normal term gennaios. [28] The Theaetetus passage should have prevented ironic interpreters of the Isocrates-praise at least from claiming that this word in particular is inappropriate for Socrates’ sincere admiration. [29] If Plato and Isocrates are each other’s determined opponents—and this is too complicated an issue to be decided easily—their rivalry depends on some surprisingly close connections, and we should look carefully for signs in both authors of consciously moving closer still to the other’s ideas: a strategy to supplant the opponent’s claim, but one necessarily involving some compromises.

Before moving on to the art of medicine, we should briefly consider the lofty and showy language Socrates uses at Phaedrus 270a to talk about the Hippocratic method and its basis in knowledge of ultimate truths about the cosmos. Socrates asserts that “All the great arts require endless talk and ethereal speculation [adoleskhias kai meteōrologias] about nature” (trans. Nehamas and Woodruff 1995), and he adduces the support of Pericles’ decisive encounter with Anaxagoras, from whom the great orator (pantōn teleōtatos eis tēn rhētorikēn) learned “the nature of mind and mindlessness.”

I am interested in this particular passage because its ironic touch seems to suggest a knowingness on Socrates’ part that the presumption of an absolute and all-encompassing source of truth about nature is somewhat ridiculous, especially when brought to bear on the real problems of the political world. The word adoleskhia means “nonsense and foolery,” [30] but a need to defend the supposed high seriousness of Plato’s rationalist principles has caused LSJ and some interpreters to invent a special sense found only in this passage, “keenness or subtlety.” Robert Joly, for example, is compelled to endorse the idea that Pericles fits the model of a “savant désintéressé,” [31] when anyone who has read the Phaedo knows that Anaxagoras is truly a “mindless” [32] basis on which to build a science. This bit of humor sharpens the problems with supposing any understanding of nature to be a reliable foundation on which to build an art that has to work in practice; at any rate, the cosmology of a work like the Hippocratic Regimen, despite Socrates’ explicit statement that a true tekhnē should have such a basis, does not impress us any more, and is unlikely to have impressed Plato any more, than that of Anaxagoras. Pericles is ignorant of Socratic dialectic, anyway, and he comes off looking more like the Socrates of Aristophanes’ Clouds than anyone else.

Plato seems to use the word adoleskhia in smiling reference to a certain kind of inspiring mystical claptrap—perhaps politically powerful or heuristically valuable, but not the product of philosophical rigor. [33] Socrates’ remark to Hermogenes, at Cratylus 401b, that the first name-givers were meteōrologoi kai adoleskhai tines, is typical. Ultimately, the fact that Plato will turn to such storytelling larks at times of evident philosophical seriousness, as here in characterizing the epistemic foundation of Hippocratic medicine or rhetoric, is a subject larger than I can deal with here. As with the priests and poets of the Meno, or the corybantic buzzing in Socrates’ ears in the Crito, and as with the powerful influence of Eros, Muses, and cicadas in the Phaedrus, sometimes Plato’s Socrates signals a playful awareness of the conjectural boldness with which he paints some of the most daring and important strokes on his canvas. These free and lofty gestures are interesting to consider as an alternative to admitting the style of knowledge and phronesis cultivated in the practical arts tradition: both are ways of containing the irrational within a system.

Plato may be echoing Isocrates’ Against the Sophists 7f., where Isocrates uses the similar phrase adoleskhian kai mikrologian in reference to charlatan professors who keep closer watch over discrepancies in logoi than in actions, and who “claim to know about future things, but concerning present things are unable to speak or advise any of the things needful.” The result is that care for the soul (tēs psukhēs epimeleian) is brought into disrepute. This is in part a warning against handbook-precept and theorization run amok, and since we know Plato is largely sympathetic to this aspect of the critique, it is not unreasonable to think it a sympathetic borrowing. Yet Isocrates also points to the inescapable challenge of engaging with the actions taking place in the present, and this aspect of the critique is a source of more tension within the Phaedrus.

The prestigious model for Socrates’ true art of rhetoric in the Phaedrus is the medical art of “Hippocrates.” [34] Although Socrates’ use of this model in the first place demonstrates an acceptance that philosophical rhetoric will still be a practical art and conform to the model of some existing practical art, he also attempts to elevate the system of Hippocrates, with its concern for “the nature of the whole” (Phaedrus 270c2), above the less scientific practice of other physicians, who, like the run-of-the-mill speaker, rely upon experience instead of knowledge. While I accept that this is a doctrinally crucial distinction for Plato, a look into several texts of the Hippocratic Corpus shows how hard it is to enforce, in practice, on the landscape of Classical Greek medical theory. I suggest that Plato’s elision of the ambivalences to be found in the medical texts shows how powerful a claim the authority of the methodological discourses of the practical arts, considered more broadly, held over him, and how much ground he consequently had to yield to them in order to sustain his construction of any new kind of rhetoric.

The Hippocratic treatise Regimen may roughly exemplify the rationalist method of Socrates’ Hippocrates, but it too evinces certain reservations about the scientific precision of medical practice. Hutchinson takes Regimen as the appropriate parallel and cites two passages (Regimen I 2 = VI 470–472.28-40 Littré and III 67 = VI 592.1–12 Littré) in which even that author—for whom a Presocratic-flavored cosmology is a truth, graspable by reason, from which all sound medicine can be derived—acknowledges the limitations of knowledge. [35] For all medicine had to address the frequency of the art’s failure. [36] Medicine for this author is, as Hutchinson puts it, “a comprehensive body of profound and hidden truths which it is difficult to apply precisely.” The final phase of medical therapeutics resists prescriptive knowledge: the proportion of food and exercise for each individual constitution (pros hekastēn phusin) is impossible to discover (adunaton heurein). [37] Likewise, “Concerning human regimen … it is impossible to treat it in writing [xungrapsai] with precision [es akribeian], so as to make a due proportion of exercise in relation to the amount of food” (III 67, 1–3), and the elements of diet, “all differing from each other [diaphora], prevent the possibility of precise written formulation [es akribeian xungraphēnai]”(III 67, 11–12).

It will come as no surprise that, from my view, these citations suggest a compatibility between even this most rationalistic treatise, suggested as Plato’s referent, [38] and the principal case in which Isocrates stresses knowledge’s limitations. So, without disputing that a work like Regimen demonstrates an ardent belief in basic and universal truths that echoes Plato’s faith in dialectical knowledge much better than anything in Isocrates, I have to differ with Hutchinson when he goes on to cite Antidosis 271, in contrast, as a clear expression that only “sound opinions,” and not “exact practical knowledge,” are worth the orator’s pursuit; [39] the different interpretation of this passage I have offered above has more points of connection to the way the author of Regimen thinks about his practical tekhnē. [40]

In fact, there is considerable uncertainty about which text from the Hippocratic Corpus, if any, to nominate as Socrates’ referent, and this is symptomatic of the fact that all the Hippocratic writers, on both sides of the methodological debate to be found within the corpus, embrace the value both of system and of a realistic understanding of the limitations on applying precise knowledge to the circumstances of actual experience. Jaap Mansfeld was able to nominate Airs, Waters, Places instead. [41] The treatise On Ancient Medicine, rightly chosen by Hutchinson as a clear exponent of an empiricist methodology closer to Isocrates, in its turn contains many statements and tendencies closer to the kind of medicine Socrates admires. As Mark Schiefsky says: In fact, Schiefsky comes to the conclusion that “only in VM do we find an explicit recommendation of something like the method Socrates describes as a method of investigating human φύσις,” so that, “If Plato had in mind any of the texts that make up the present Hippocratic Corpus, surely it was VM,” notwithstanding the evident differences between the two theories. [43]

This methodological ambivalence is everywhere in the Hippocratic Corpus. Joly has given reasons for skepticism about whether any neat, discoverable, or reconstructible Hippocratic analogue can lie behind Plato’s “Hippocrates”; the search for “strict parallelism” could be misguided, since medicine in the Phaedrus primarily serves the function of expressing what the orator’s art does in connection with his hearers’ souls. [44] Jouanna’s characterization of the treatise On the Nature of Man is typical: Indeed, I suggest that this methodological ambivalence is more generally appropriate to the practical arts (in particular, Isocratean rhetoric), and we have seen that we must take very seriously Plato’s engagement with this kind of methodology in the Phaedrus.

In fact, while in principle any practical art could and should have sought and developed a flexible methodology capable of marrying experience and doctrine, it seems that rhetoric and medicine were unusually advanced and sophisticated examples of this enterprise. An examination of harmonic theory shows that, even when we hear in our texts of an “empiricist/rationalist” polarity, this may not really betoken the existence of a school committed to facing the complex uncertainties of lived experience in the manner of some rhetorical and medical theories.

Among the various writers and movements in the practical arts, [46] the harmonikoi criticized by Aristoxenus, a Peripatetic harmonic theorist perhaps fifteen years younger than Aristotle, make a good test case. For their “empiricist” methods were found provocative in a field with a strong rationalist and mathematical tradition going back to Pythagoras. These harmonikoi seem to have offered “arguments [that] depend wholly on their views about the intervals that can reliably be identified by the ear.” [47] “In this method of describing musical structures, then, it is possible to conceive, for example, the interval of a fifth as three and a half tones without reference to the ratio of 3:2 and in this way it is more compatible with the way that the human mind perceives music. Likewise … a semitone could be perceived as an interval half the size of a tone.” [48]

It is tempting to analogize the ear’s data in this system to the imprecise experiential information upon which orators and physicians must base their actions. But there is no evidence that the errors and incompleteness of perception were problematized in this school, not to mention any evidence that such problems were then considered practical (as opposed to merely descriptive) problems. We can only speculate. Barker couches such a speculation in conditional form. Just as On Ancient Medicine rejects “empty postulates” about the “nature of man” and challenges physicians to “work on the basis of empirical observation of experience,” “I suggest that the harmonikoi of this early period, if they had considered the matter, would have taken a similar view about their own art.” [49] Unfortunately, the counterfactuality of this intriguing “if” must be underscored; by Barker’s own analysis, the harmonikoi do not seem to have moved in this direction, but instead to have retained the theoretical framework of the systematic handbook. [50] This inability to develop principles of performance sophisticated enough to take into account their awareness of the “flux of phenomena” put the harmonikoi in the awkward position of singing and playing “intervals which are outlawed by their own theoretical position.” [51]

If this characterization is correct, we have to do with a failure to develop a theory that makes room for experience’s discrepancies from rationalistic canons. The most we can say is that perhaps this view of the harmonikoi as incompetent and inconsistent handbook-drafters (adherents to tetagmenē tekhnē in the Isocratean sense) is to some degree an incomplete and unfair caricature, based as it is on hostile witnesses. [52] There could have been an innovative critique here of music’s epistemological foundation, in the spirit of Protagoras’ man-measure doctrine. [53] But just as it is difficult to reconcile Protagorean epistemology with the Protagorean theory of practice (the wise man’s pursuit of virtue, as developed in Plato’s Theaetetus), we are at a loss for evidence to say that the harmonikoi were led by their ear-criterion to engage in the problems of empirically based practice. [54] Medicine and rhetoric—to some degree because of the better extant sources, and equally importantly because of the seriousness with which Plato and Aristotle were driven to engage with their ideas—are revealed in comparison as more than an effective working-out of problems by technical practitioners, but rather a theoretical tradition of broad importance for all rival Greek theories of practice.