Plato’s Political Epistemology

• The Political Science Reviewer • Volume 48, Number 1 • 2024

Devotion to the truth is a virtue that is noticed mainly by its absence. In recent years Americans have been surprised by the fraying of a fabric we have long taken for granted. While few of us dedicate our lives to learning, we have generally respected the expertise of those who do and have entrusted our children to schools and colleges where we expected the unprejudiced pursuit of truth to prevail. While we recognize the proclivity of political leaders to bend and stretch the truth, we have expected them to listen to experts, to work hard to persuade reasonable minds, and to be kept in check by a vigilant, generally fair-minded press. While we know our fellow citizens are often poorly informed, we have trusted in their fundamental reasonableness and willingness to listen to evidence. Above all, we have trusted that there is a truth to be found and worth finding, and to that end we have supported extensive freedoms of speech and press. Today, however, confi- dence in experts, universities, leaders, journalists, our fellow citi- zens, and our First Amendment rights is in decline. On both left and right we see remarkable rejections of open, truth-seeking dis- course as discussion is muzzled on one side by cancel culture and poisoned on the other by conspiracy theories. Are we approaching the end of an era, and is the Enlightenment project even proving an experiment ill-suited to a generally truth-averse human nature? Worse still, are we discovering that truth itself is an ill-grounded construct, always perspectival, ultimately unverifiable, perhaps never claimed without some power-seeking motive?

The deeper reaches of these questions were well known to the ancients. Plato’s dialogue on knowledge, the Theaetetus, is remarkable in taking as Socrates’s immediate interlocutor the young Theaetetus, who even as an outstanding student of mathematics has a fraught rela- tionship to the truth, and as its central implicit interlocutor the sophist Protagoras, the father of radical relativism. The trilogy of Theaetetus, Sophist, and Statesman as a whole confronts the problem that if we cannot isolate the sophist and distinguish him from the knower, we also cannot separate sophistry from statesmanship, for all claims to know justice and the common good will be ungrounded. Can pure knowledge be found somehow, then, in a realm beyond power strug- gles, prejudice, and self-interest—perhaps in a higher realm alto- gether beyond the limitations of our mortal, embodied existence, as Socrates intimates in his parting consolations to his grieving friends in the Phaedo? Plato’s more sober Theaetetus—the Platonic dialogue devoted to knowledge—suggests, rather, that wisdom is all about understanding ourselves as the embodied, mortal, needy, acquisitive, honor-seeking, victory-loving social and political beings that we are.1

This article proposes a unified interpretation of the major moral and political themes in the Theaetetus, arguing that together they provide the key to Socrates’s successful response to relativism. First, I locate in the dialogue’s explicitly political frame signals of the centrality of human mortality and the tension between philosophy and politics for thinking through the problem of human knowledge. Second, I explore Socrates’s suggestion that Protagorean relativism, and behind it the motion thesis Socrates attributes to Heraclitus and Homer, constitute the challenge that philosophy must address in devising an adequate theory of knowledge. Third, I bring together the midwife story and the digression to offer clues about how Socrates’s interroga- tions of justice respond to the deepest challenge of the motion thesis that he presents as the strongest argument for relativism. I then trace in detail his reflections on a range of passions and concerns that can obstruct the quest for truth, including honor-seeking, acquisitiveness, power-seeking, diffidence, fear, excessive hopes, and perfectionism, showing show how the dialogue reveals each of these problematic tendencies to be closely tied to passions that drive the quest for truth and to abilities and dispositions that allow us to get at the truth in the first place. Finally, observing the yearnings that must be curbed to accept Socrates’s sober indications about what it means to know, I use the aviary image to unpack his depiction not of knowledge as a perfect possession of eternal forms but of knowing as an impassioned, rela- tional, mortal, and thoroughly human activity.2

The Citizen Philosopher and the Citizen Geometer

The sublimely theoretical conversation between a philosopher and two mathematicians that makes up the body of the Theaetetus is punctuated in the dialogue’s opening and closing scenes by sharp reminders of war, political persecution, and death. The framing dialogue between Socrates’s former companions Euclides and Terpsion, set some years after the death of Socrates, begins with reports of the now mortally wounded “noble and good” Theaetetus, both a great geometer and a war hero, struck down in battle on behalf of Athens and determined to reach home again even if the journey should hasten his demise (142a–c). It continues with an account of how Socrates, in prison awaiting execution at the hands of Athens, related his conversation with Theaetetus to Euclides, who transcribed and preserved it for posterity. Politics obtrudes again in the last line of the dialogue as Socrates discloses that he must end this leisurely discussion of knowledge to go answer Meletus’s charges in court.3 These two abrupt reminders of human mortality and of the philosopher’s fraught relation with the political community suggest that a good place to begin in making sense of this aporetic dialogue may be precisely with these perplexities: How might death and the human yearning to escape it and the problem of justice as the city understands it both be important for understanding knowledge?

The opening exchange of the main dialogue continues the political and moral themes, as attention shifts from the detached Euclides in his search for the perfect, permanent philosophical transcript, to Socrates the citizen philosopher, who has left the city only to fight for Athens and who will refuse to flee when the city’s laws condemn him to death, still seeking promising students at the very end, especially among his fellow citizens, inquiring into their families and charac- ters, and eager for partners in ongoing investigations of problems he does not yet adequately understand. His first round of exchanges with young Theaetetus is personal and provocative, beginning with the question of how these two similarly ugly individuals look to each other and to others and ending by turning the quest for knowledge into a competition in which whoever speaks badly must “sit down an ass” and whoever speaks well will become the group’s “king” (146a).4 Thus Socrates invites us to start pondering another perplexity: How is character relevant to the question of knowledge, and why is Socrates so disconcertingly personal?

In Euclides’s project we see what philosophy is not: a series of doctrines perfectly distilled and demonstrated, preserved and avail- able for retrieval at any time by anyone—a safe refuge from the sometimes sickening flux of human affairs. Even more than most Platonic dialogues, the Theaetetus forces us continually to think for ourselves and thereby demonstrates what real knowing must be. It proceeds by raising subjects for reflection, sometimes posing ques- tions without answering them, sometimes taking us down blind alleys that highlight significant errors to be avoided, and most intriguingly by outlining strange arguments that when properly developed and qualified prove surprisingly powerful.5 The dialogue demands active reflection not only about what knowledge is but also about what it means to each of us and what deep hopes, fears, and attachments pull us toward certain ways of conceiving of it and away from others. For Socrates and his successful students, the search for knowledge is both personal and interpersonal, a playful but serious competition in which each must put his thoughts to the test and his soul on the line. For Socrates the citizen philosopher, political and moral questions are never absent from his thoughts in even the most theoretical discussions.

For Theaetetus, in whom the Athenian gentleman and the thinker constitute such distinct parts of his soul, mathematical achievements of the highest order are possible, but is philosophy—without which the status even of mathematics remains obscure?6 Even if Theaetetus is spirited enough to be a war hero, is he strong enough to confront the tangled hopes and attachments he harbors in his soul? The same spiritedness that fuels political ambi- tion can fuel the pride that makes exceptional souls intolerant of self-deception, even while it makes their moral attachments espe- cially vivid and hence especially accessible to self-criticism: hence politically ambitious youths hold a special attraction for Socrates. But he is also interested in a brilliant geometer like Theaetetus, who resembles and perhaps reminds him of his younger self, and whose intense ambition simply to know is especially conducive to the inquiry into knowledge.

The Protagorean Challenge

Even more important than Socrates’s direct interlocutor Theaetetus, however, is his implicit interlocutor Protagoras. By giving Protagoras a central place in his dialogue on knowledge, Plato pays homage to Protagoras’s unusually keen recognition of the grav- est challenges to human knowledge. When Theaetetus proposes his definition that “knowledge is nothing other than perception,” Socrates equates this to Protagoras’s famous statement, “[O]f all things a human is the measure, of things that are that they are, and of things that are not that they are not” (151e–52a).7 As Socrates begins to unpack Protagoras’s claim, he interprets it to mean that all we have is our own experience, which varies from person to person and for each person over time as our conditions and passions change. Reading the Theaetetus in our present predicament, it is intriguing to watch Socrates grapple with Protagorean arguments of surprising contemporary relevance: the denial of objective truth or a shared reality and the insistence that each person is the only authoritative interpreter of his or her own experience, together with the claim nevertheless to know what is good and to be able to give political guidance—claims that Socrates brings into juxtaposition in the long speech he offers on Protagoras’s behalf at 166a ff. As we shall see, Socrates deftly exposes the tensions between Protagoras’s deep skepticism and his bold claims. Nonetheless, Socrates identifies behind Protagoras’s relativism three powerful lines of thought that he suggests a serious investiga- tion of knowledge must confront at the outset.

The first is the idea, which Socrates traces back to Heraclitus, that “nothing ever is but always becomes” (152e). Nothing is fixed; indeed, nothing exists at all in the way we habitually take that word to mean; there is only flux. Socrates does not so much refute this radical motion thesis as show that it cannot coherently be spoken or thought. Even if “things” in our “world” are much more in flux than we have ever suspected—even if at the bottom of “everything” is only energy, for example—nonetheless motion without anything that in changing place remains itself, or change without anything that in altering remains at least for a time one being or becomes some new being or beings, is not thinkable (181b–83c).8 Still, might this not somehow be the true state of affairs, even if we cannot speak it consistently?

The second line of thought that Socrates finds behind Protagorean relativism in one way deepens this problem but in another way points to a path forward. This is the thought that all our experiences and judgments arise out of interactions between ourselves and something—the account calls it “motion”—to which in itself we have no access (156a). Out of the encounter between something that produces the experience of whiteness and an eye, for example, comes a seeing eye and a white stick (156e). With this formulation Socrates suggests that if all knowledge is in some sense perception, the perceiving mind’s interaction with whatever is around it in an important way constitutes the beings and the world of our experience. But if this is true of the beings, it must be no less true of motions and qualities and quantities: they are not in them- selves; they are only for someone (157a–b). Might this not be precisely what it means for anything to be? Socrates surrounds this argument with extreme statements of the motion thesis, including the claim that “the all is motion and beyond this there is nothing else” (156a), so we ourselves would be nothing but motion, in a way that makes it look highly suspect. He presents it—as perhaps Protagoras presented it—without sufficient emphasis either on the enduring potentialities that must exist in both ourselves and the world for our experience to be as it is—potentialities that the whole dialogue keeps pointing to but which Socrates leaves it to Theaetetus and Plato to the reader to discover the importance of—or on the active mind that through the senses experiences and makes sense of the world—a crucial supplement to this argument that Socrates will offer only later (184b ff.). In these ways Socrates distances himself from Protagoras’s thought that to be is to be for someone, but he never refutes it—and indeed his incessant atten- tion to who it is that is perceiving or thinking suggests his receptiv- ity to this thought. This form of relativism, which when supplemented by close attention to the role of mind we may call noetic relativism, may be one part of the Protagorean challenge that Socrates considered especially compelling.9

Might it be true, then, that “things in themselves” not only are inaccessible but also have no truly independent being and that knowledge of the world is all a matter of observing closely and giving a careful, phenomenological account of human experience? If this is all philosophy can do, it may still be a great deal. Yet the third line of argument Socrates attributes to Protagoras threatens even this possible project. Perhaps the world of our experience is an island of temporary appearances in a sea of wild, unfathomable flux; perhaps at the source of things are mysterious, willful gods. Socrates indicates the importance of this religious challenge to philosophy by calling Homer the “general” of the whole army of thinkers who have propounded the motion thesis that undergirds Protagorean relativism, and by calling attention to Zeus’s claim of extraordinary powers over the world and the other gods (153a, c–d).10 True, Homer hints that Zeus’s claim may be a boast. But is pre-Socratic philosophy any more successful than Homer is at proving that it is not a boast and that unchanging natural necessi- ties govern everything? Failing that, philosophy itself is a boaster, and Protagoras deserves credit for acknowledging more forth- rightly than his predecessors and contemporaries that he has no way to dispose of this challenge. “About gods,” he reportedly wrote, “I am not able to know that they are or that they are not, for the impediments to knowing this are many, both the obscurity involved and the brevity of a life of a human being.”11

Evidently under the influence of all these considerations, Protagoras drew radical conclusions, most fully elaborated in the long speech Socrates gives on his behalf at 166a ff. Not only do we each have only our own experience, not only is that experience private and unique for each of us, but we each have only our present experience. Even memories are not knowledge of a fixed past but are new experiences each time they occur. Indeed, we ourselves, ever experiencing new things, are new persons at each moment, or rather new multitudes, without any unified or stable core. In effect, Protagoras is saying, the whole world of our experi- ence is like a movie playing privately for each of us, every part of which is as real and true as every other, so that each individual is the measure of his own truth. With this argument the claims of both prophets and natural philosophers are undercut: Tiresias’s claim to speak with Apollo may be true for him, but it is no more true for anyone else, and the same holds for Democritus’s theory of atoms. What is not undercut, if framed with sufficient caution, is a certain kind of sophistry. Protagoras could say, with a modesty he apparently never actually practiced, “my account of human experi- ence is merely the way things seem to me; I seem to be able to help people have more success and more pleasure in pursuing the things they seem to want, and in that I take pleasure myself.”12 The fact that Protagoras was never so moderate might be only of biographical interest. The philosophical question, a question Socrates presents in the Theaetetus as a terrible challenge to philosophy, is how to overcome the profound doubts that Socrates suggests dogged Protagoras and the others who embraced the motion thesis, at the head of whom stood Homer with his stories of powerful, willful, providential gods.

Socratic Dialectic

According to hints scattered throughout the works of Plato, it is especially this problem that prompted Socrates’s famous “second sailing,” his turn from the attempted direct contemplation of beings or being to the dialectical examination of speeches or opinions, with particular attention to the relation between humans’ tangled opin- ions about justice and their experience of the call of the divine.13 The Theaetetus sheds light on this project only obliquely, through a thicket of allusive hints in two digressions, the story Socrates tells Theaetetus likening his dialectic art to midwifery at 148e ff. and the excursus on the philosopher in the city that he engages in with Theodorus at 172c ff. In both, Socrates talks with unusual directness about himself and his cross-examinations of others. Both are rife with curious claims about philosophy and divinity and with allusions to the Apology, Socrates’s dialogue with the city of Athens in which his own cross-examinations become the theme and which seems to stand as the missing dialogue on the philosopher promised at the beginning of the Sophist.14 The dramatic functions of these two digressions are similar as well. In the midwife story Socrates coaxes a discouraged and suspicious Theaetetus to trust him, and in the later digression he encourages a wary Theodorus to embrace an inspiring account of philosophy and perhaps ultimately to join in its gentle defense against a hostile city. To this end both philosophic and political men appear in most of the digression in caricature, the philosopher, unlike Socrates, as too pure, high-minded, and detached to take politics seriously, the political men nothing but petty lawyers and shysters. But both the midwife story and the last part of the digression, where the philosopher suddenly shifts to resemble Socrates, cut deeper to reveal something important at the heart of Socratic dialectic.

Echoing his strange claim in the Apology to have been compelled by the god Apollo to engage in cross-examinations in an effort to refute the god (21a–b, 21e–22a, 22e–23c), Socrates claims in the midwife story to have been compelled by Artemis or by some unnamed male god (150c–d) to practice midwifery. Echoing his repeated professions of ignorance in the Apology, Socrates claims here to be himself barren of knowledge—although with a hint that if his case does parallel that of female midwives, he must once have been fertile (cf. 149c, 150c).15 This hint, too, has a curious parallel in the Apology, for despite Socrates’s professions of ignorance there, his story implies that he must have impressed his companions as extraor- dinarily wise before Chaerephon went to Delphi to ask the question that set off his career of refutations. Perhaps Socrates once devel- oped insights of his own, but in this phase of his life his

most important work is testing others as they fall into wrenching perplexity—perplexity that he hints must have once gripped him and that he cannot resolve for them but can only attentively watch them wrestle with from the sidelines. Perhaps relevant is Socrates’s comment in the Phaedrus, explaining his turn to dialectics, that he wants to know whether he is a strange and monstrous being or whether others are like him too (229c–30a). There is something about the perplexity he induces in students that they must ultimately sort out for themselves; offering them solutions ready made, even if he could, would do neither him nor them any good.

Socrates’s midwife account continues with a cascade of refer- ences to the divine and to the divine art that he first attributes to the god (150c), then to the god and himself (150d), and finally to himself alone (151a), ending with the strangely impious non sequi- tur that many are angry when he refutes them, not understanding “that I was doing this out of goodwill, since they are far from know- ing that no god has ill will towards human beings.” To this he hastily adds, “nor do I do such a thing through ill will either,” concluding that for him to go along with anything false or to conceal what is true is not sanctioned (athemis)—just what he says of the god in the Apology (151c–d, Apology 21b). Is Socrates barren and igno- rant, or wise and somehow even divine?16

At the end of the digression on philosophy and the city, Socrates again depicts his refutative activity and now reveals elements of it that the midwife account left obscure. Those interrogated are espe- cially ambitious young men who before seemed clever to the city and to themselves, and the topics of interrogation are especially justice, injustice, kingship, and human happiness and misery (175c–d).17 Socrates also indicates here key conclusions that his philosophic practice has led him to, which concern the nature both of happiness and of the divine. First, in a way reminiscent of the Phaedo, he char- acterizes happiness as escaping this human realm of troubles to the divine realm as quickly as possible, explaining that “escaping is becoming like a god as much as possible”—suggesting indeed a flight from this earthly realm—but then adding that “becoming like a god is becoming just and pious with wisdom (phronesis)” (176b).

Essential to this wisdom is understanding that virtue is good and vice bad, not chiefly for their appearance and hence for the ensuing rewards and punishments (176d–77a) but for themselves—from which it follows that retribution is neither just nor wise, as Socrates argues in the Gorgias and elsewhere—that no god is unjust, and indeed that true wisdom and true virtue are the recognition of all this.18 Commentators on this passage have questioned whether it makes sense to attribute moral virtues and especially piety to the divine,19 and even the wisdom described here seems to be human, practical wisdom. But if “gods” as individual beings can be neither pious nor in any need of practical wisdom, might wisdom even in its practical manifestations still be what is in fact most divine? These thoughts may illuminate Socrates’s strange assimilation of himself to the divine in the midwife story. Somehow, through an inquiry he connects with his midwifing and with his discussions with political men about justice, kingship, and happiness, he has become confi- dent that such divinity as exists is neither retributive nor otherwise hostile nor mysteriously willful but that the highest thing in the cosmos is intelligence of a kind that humans who strive diligently may come to access or even embody.

Just at this point in the digression Socrates brings the argument back to Homer, quoting a Homeric epithet as he contrasts his view with that of unjust political men who think themselves clever in being not “useless burdens on the earth” but “men such as one must be to be safe in the city,” who in fact are “ignorant of the penalty for injustice they should least be ignorant of,” the condition of their own souls (176d). This epithet is famously spoken by Achilles in self-reproach for sitting idle, “a useless burden on the earth,” instead of protecting Patroclus (Iliad 18.104). As Socrates deploys it here, however, its spirit best fits its other usage in Homer, where it is hurled by Penelope’s insolent suitors at the powerless Odysseus (Odyssey 20.379). But the scenes are related. As Achilles speaks this line he is resolving to die avenging Patroclus, with the gods’ aid, and as Odysseus hears it he is engulfed with the rage that leads him to slaughter all the suitors, helped by Athena. The view that Achilles and Odysseus share with each other and even with the suitors is that prevailing in the contests among men and protecting one’s own is all-important and that being trampled is most terrible and must be avenged at all costs. Our heroes add to this a fervent hope and belief that such vengeance, being just, must be supported by the gods. Socrates, however, is confident that both heroes are wrong, both about justice and about the divine.20 And he can show that even the “clever” political men, if they endure his questioning and do not run away, “wind up strangely dissatisfied with them- selves” and with what they thought they understood about these questions (177b).21

All this is most allusive and indirect, and appropriately so if there is something at the core of all these connections that each must think through for oneself. But if we are on the right track, the two digressions shed light on the negative or defensive work of political philosophy, not only in enlisting for philosophy more moderate defenders and deflecting the hostile suspicions of a pious city but also in defending philosophy itself against the most radical challenge to it represented by radical relativism and ultimately by Homer and Homer’s gods. If through dialectic Socrates has been able to take individuals with different beliefs about life’s meaning and different beliefs about the divine and bring whoever endures his questioning, one at a time, to see the inadequacy of his own beliefs about virtue and vice and the power of Socrates’s argu- ments, and if at the end of this road is a shared recognition that what is most divine is wisdom, then Socrates has taken an impor- tant step toward refuting the most acute challenge to philosophy from prophecy and poetry. At the same time he helps confirm that he himself is not some strange and monstrous being (Phaedrus 229c–30a) but a member of a human race with importantly shared apprehensions of things and even of good and bad, beneath all the apparent differences. These are many big ifs, to be sure, and the relevant refutations are enacted in other dialogues, not here. The main work of the Theaetetus is to think through what it means to gain solid knowledge of the world of shared experience if it is possi- ble for human beings to do it at all. Yet a fascinating thing about this treatment is that it is precisely Socrates’s human-focused, opinion-querying, political approach that allows him to make head- way here too.

Opinion and the Concern with Recognition

In his refutation of Protagoras that begins in the section immedi- ately following Protagoras’s long speech, Socrates does not dispute the important Protagorean premise that we each have our own perceptions that are on some level irrefutable (171d–e, 179c). On this basis he asks, in effect, why is it nevertheless not the case that we each experience the world as we might a dream or an ever- unfolding movie playing just for us, in a series of impressions all equally real and irrefutable, with the result that, as Protagoras claims, each is equally the measure of what is, and none can be said to have false opinions (167d)?

Socrates’s first refutation of Protagorean relativism focuses on a phenomenon that Protagoras treats with great apparent deference and actual casual disregard and that Socrates is forever challenging but in fact takes with utmost seriousness—common opinion. It is in the examination of ordinary opinion that Socrates finds the key to addressing the challenge of radical uncertainty and flux not only from the poets’ direction but also from that of early philosophy. Socrates reflects carefully on both the content and the structure of opinion, including the complex way it emerges invariably out of perception and infuses perception, the way it can turn to reflect on itself, and the way it confirms that we inhabit a common world. From arguing for the truth of each person’s perceptions (aistheseis) and of what appears to him (to phainomenon, 166c), Protagoras slides into arguing for the truth of whatever each person opines (doxadzo, 167a–d), without careful reflection either on the subtle relation and difference between perception and opinion or on the fact that ordinary opinion is unanimous precisely in judging opinions to be unequally valid. At 170a Socrates highlights Protagoras’s subtle shift from a claim about what appears to each (dokei) to one about the opinions humans hold (doxa). In querying the truth of all opin- ion, Socrates presses especially the question of whether all share equally in practical wisdom (169d), thus highlighting the connection between wisdom and human neediness. He points out that espe- cially in crises all show their recognition that some are wiser by seek- ing out experts to guide them. Thus, if ordinary people are the measure of what is, ordinary opinion is unanimous in lining up against Protagorean relativism, and Protagoras himself provides the final exquisite vote against himself with his endorsement of everyone else’s opinions as to the falsity of his own claim, which is not recipro- cated. Hence, Socrates concludes, “the Truth of Protagoras will be true for no one” (171c).22

When to all this Theodorus protests that they are running down his old friend too much, Socrates politely surmises that if Protagoras were there to speak for himself, he would doubtless have something else to answer. But what could this be? Protagoras could avoid self-contradiction by presenting his view as merely the way the world appears to him or by retreating to utter skepticism. Both would seem impossible for Protagoras, not only because he evidently thinks he does have hold of something true and valuable for others but also because he loves being honored for his wisdom. This same thirst for honor evidently drives his imprudent openness that Socrates criticizes in the Protagoras; it drives him to seek a big following rather than looking for the best partners in inquiry; as we see in the Protagoras, it drives him to conceal his inconsistencies rather than examining them.23 In all these ways the love of honor can corrupt the quest for the truth. But these concerns of Protagoras are far from idiosyncratic.

Even Socrates shares Protagoras’s concern with others’ judgments. For Socrates too is a teacher, and being a teacher at the highest level is all about trying to make sense of the world, trying to formu- late one’s ideas as cogently as possible, testing them in conversation with bright interlocutors, and trying to give those ideas legs. Success in this is valuable confirmation that one is on the right track, and as such it is gratifying. The danger of getting the cart before the horse and allowing the gratification to matter more than the confirmation is of course universal and serious. But this horse and cart cannot be unyoked: the concern to make sense both to oneself and to others and to win respect for one’s understanding is a single human concern, especially evident in experts and would-be experts but present in all of us. As Socrates observes, humans are forever forming opinions not only about their own experience but about one another’s experience as well, comparing impressions and trying to prove each other right or wrong. Theodorus laments the contentions that his pursuit of science brings on him, but he, too, is a teacher, trying to win confirmation for his own insights from others. More fundamentally, the desire to share and confirm our experiences is what spurred humans to develop the language that knowledge requires; it is what spurs every writer to write. The same concern to make sense and to make sense to one another— and the anger that can arise when we fail—is likewise what allows Socratic dialectics to work.

Thus the world of our experience is, willy-nilly, a world of inter-subjective reality and intersubjectively confirmed differences in degrees of understanding. For all his impressive attention to the varieties of human experience and his powerful claim that that we cannot get behind or above our experience to any absolute things or world that absolutely exist “in themselves,” Protagoras is being a poor phenomenologist in failing to reflect sufficiently on the funda- mentally social structure of human experience. Hence his relativism falls into incoherence in attempting to maintain that what “we” each have is just “my own” irrefutable appearances and impressions and opinions. The problem is not just the logical problem, grave as it is, that to fend off his critics Protagoras would have to affirm as merely relative truth precisely his critics’ assertion of the nonrelative charac- ter of truth. The deeper problem for Protagoras involves the kind of world he experiences himself as inhabiting. His attempt to articulate how the world is for each human being betrays his crucial recogni- tion that the world—even and precisely his own world—is shared with others who exist not just “for him” as figures in the movie play- ing in his own mind but as independent centers of experiences and judgments.24 It is this basic structure of experience that Protagoras needs to think more deeply about. If he did—if we did, as Plato is evidently prodding us to do—we could begin to see the outlines of a possible middle ground between the each-man-is-the-measure relativism, which on any attempt to make it rigorous collapses into solipsism, and the absolutism of purported truths in themselves about things in themselves and the world in itself that Plato’s Theaetetus so quietly yet powerfully puts before us as problematic. This middle ground would grant that to be is to be for someone, that to be true is to be true for some thinking being; it would accept that we have only our own experiences to work with; but it would give equal weight to our humanly shared capacity as social and political beings to reflect on these experiences, on ourselves, and on one another. On this basis, it would seek to articulate the structure and features of our richly ordered and nuanced collective world.25

This section of the dialogue points twice to the great feature of human life that casts most serious doubt on the extent of our shared experience—namely, religious experience. As Socrates indicates, in crises people turn not only to human experts but to diviners, and Theodorus’s troubles are brought on by the popular suspicion that students of natural science are atheists (170a–b, e). These twin chal- lenges to philosophy from piety, one theoretical and the other politi- cal, set the stage for the digression that will give indications about Socrates’s response to both. In the remainder of his discussion with Theodorus, Socrates continues the project of putting philosophy on a sound footing by showing how, apart from purported divine inter- vention, human experience is far less fragmented and far more amenable to a solid, shared articulation than Protagoras supposed.

Acquisitiveness and the Arts

Beginning just before the digression and resuming immediately afterward, Socrates strengthens his case against Protagorean rela- tivism through a sustained focus on the arts. Appealing to Protagoras’s pride in his own art as a political adviser, Socrates distinguishes the realm Protagoras most consigned to the flux from the realm that he almost certainly did not:

About political things, whatever sorts of things each city supposes are noble or shameful, just or unjust, holy or unholy and sets down as lawful for itself, these also are that way in truth for each, and in these things no private person is any wiser than any other, nor is any city wiser than any other, but in setting down what’s advantageous or disadvan- tageous for itself, here again, if anywhere, he’d agree that one advisor surpasses another and that the opinion of one city surpasses another in relation to truth, and he’d hardly have the daring to say that whatever a city sets down as advantageous for itself, supposing it to be so, is also what will be advantageous to it beyond question. (172a–b)

Now possibly at moments, despite the strong claims to know good and bad that Socrates attributed to Protagoras in his long speech (166e ff.; cf. 169d), Protagoras did dare to say this. What is more doubtful is whether, when the question was brought back to his own art for which he claimed to deserve such great fees (161e, 167d), Protagoras would ever have conceded that he was a mere manipulator of appearances without any true ability to benefit anyone.26 Was it just his desire for money that kept him from espousing complete skepticism? Certainly acquisitiveness can corrupt the search for the truth and in some ways likely did so for Protagoras. Yet it also put him in touch with something important and in a way even kept his feet on the ground. For acquisitiveness is intimately related to another fundamental structure of human experience that drives us to seek truth and enables us to do so successfully in the first place—the concern with future advantage. But Socrates somehow finds himself sidetracked in pressing this question. If Protagoras did affirm both the relativity of the noble, just, and pious and the knowability of the good, his position would be a variant of conventionalism, and it is the problem of convention- alism that derails him into the digression, which begins with the depiction of a naive pre-Socratic philosopher and ends with that of a dialectician who refutes young men about justice and ends up convinced that the virtuous are happy, virtue is knowledge, and knowledge is divine—a philosopher just like Socrates after his famous turn, who is confident that the divine realm is neither nonsense as the conventionalists asserted nor unknowable as Protagoras did.

The digression gives but a fleeting glimpse of all this without the supporting arguments, but what is interesting is that afterward, resuming the question of what Protagoras or the Protagoreans consigned to the flux and what they exempted from it, Socrates sharpens his focus to the famously Socratic question of the relation of justice to the human good. These people claim, he now says, that “regarding justice, more than anything, whatever a city sets down for itself, approving it (or thinking it so: dokei) also is just for the one that sets it down, for as long as it is set down, but about the good, no one would still be so manly as to dare to contend that what- ever a city sets down supposing it to be advantageous for itself also is advantageous for as much time as it is set down” (177d). But Socrates suggests that it is in fact the advantageous that cities look to in setting down “all their laws,” so these judgments can be falsified when a city “misses its target” (177e–78a). This claim in such a categorical form might well be queried (which Theodorus does not), but Socrates has pointed us to the cross-examinations that in other dialogues probe the relation of the just to the good. Again taking seriously what Protagoras dismisses too cavalierly, Socrates has discovered through those investigations both that human beliefs about justice, however confused, are at bottom beliefs about the human good and that true justice is either the good condition of the soul or the common good of a community and never anything either pointless or bad. If justice were merely what pleases the sovereign authority in each community, judgments about justice would be as unfalsifiable as perceptions of color or of pleasure and pain; but because communities recognize as just especially what secures the common good and try to legislate with a view to this, judgments of justice can be substantiated or falsified.

Moving beyond the art of politics, which is only one, though the most important, of human arts, Socrates now frames the ques- tion more broadly to include “the whole form in which the advanta- geous also happens to be, and that, I suppose, is what has to do with a future time” (178a). Human needs and desires and fears direct our attention continually to the future, in which we hope with present effort to satisfy our wants and secure ourselves against harms. This concern for our good may be the key to Socrates’s statement in the Republic that the idea of the good is the source of all knowledge (508e). As part of the inspiring doctrine of ideas as the true, eternal, self-subsisting beings that he proclaims there to Glaucon, the idea of the good is the idea of ideas and the source of all others; on a more sober plane, this claim may indicate that it is our neediness that first prompts us to attend closely to what is around us and to begin making sense of it. Here in the Theaetetus, where Socrates does not resort to the doctrine of ideas, he high- lights a different aspect of the same phenomenon. It is our future- oriented concern with our good that prompts us to try things out and observe how they work, to make surmises about causes and effects, to form and test hypotheses. Precisely because we can fail in these endeavors, we can gain the confidence that comes of correcting our errors; because we often succeed, we can build up expertise in the arts. Even if each of us is the authority on how we are feeling now, a doctor can make better predictions about our future condition and a chef even about future pleasures than laymen can. Thus with delicious irony Socrates shows that even if the only good Protagoras acknowledges is pleasure, merely on the basis of the arts that in the Gorgias he calls flatteries, Protagoras’s relativism still fails.27

Thus, just as our sociability and concern with others’ opinions takes us outside of our private, present experience and gives us one axis on which to confirm our hold on reality, our experience of time and especially our concern for the future gives us a second axis on which to do the same thing. It is true that memory of the past makes human experience different from a simple kaleidoscope of impressions, but to this Protagoras has the response that memories are themselves new experiences. Socrates is pointing out that the human orientation to the future is more powerful in giving us a solid handle on reality. Of course, as beings that need to attend closely to the world around us, we also find that seeing and under- standing are rewarding in themselves. But the intriguing sugges- tion of Socrates’s reflections on the role of human opinion and human future-orientation in refuting Protagoras is that a solitary, non-needy, and invulnerable being, even if perceptive and conscious, would have at best a stream of private perceptions with- out the access to robust knowledge that we have as humans.

This knowledge begins with the arts, and the paradigmatic art is the art of legislation, with which Socrates frames this whole discus- sion, though stressing its necessarily uneven success in achieving the common good (177e–78a, 179a). It is not only the ruling art but also one that illustrates well the complex and contested character of the good humans seek, the rival claimants to know it, our need to bring order to the variability of human things, and our problematic penchant for unreasonably absolute prohibitions and commands and for retribution.28 The problem of law is connected with the problem of the true source of correct law and thus with prophecy, that great rival both to the human science of legislation and to Protagoras’s art of sophistry, introduced by Socrates with an oath as he reveals that the professedly agnostic Protagoras did in fact claim superiority to all prophets, for “no one would have conversed with him, paying a lot of money, if he hadn’t persuaded his associates that no prophet or anyone else could judge better than he what was going to be and to seem to be in the future” (178e–79a). Protagoras’s sophistry turns out not, after all, to give him an island of expertise immune to the challenge of prophecy, which he knows he cannot refute. Socratic philosophy rests on a more thoroughgoing, down-to-earth effort to show that there is a single art of the human good, which he calls the political art, and that through searching interrogations of our opin- ions, especially regarding justice, we can discover a shared core to human nature and human experience and thereby get a foothold for the solid if unfinishable project that is classical philosophy.

The Love of Power and of Mastery

Protagoras is not the only character in this dialogue whose quest for knowledge is pulled off course by concerns not wholly aligned with it. Closely connected to the desire for recognition that Protagoras feels so strongly, and indeed a higher expression of the same human pleasure in preeminence, is pride in mastering the truth. Socrates is exquisitely aware of the attraction of such mastery: his favorite metaphor for philosophy is hunting. Hunting takes confi- dence and courage, and Socrates is talking to Theodorus in this section of the dialogue because Theaetetus, who has needed repeated injunctions to be bold in the search for knowledge (e.g., 148b–151d, 155d, 157d), has given up in discouragement. But Socrates also recognizes the potential corruptions of this love of mastery. To be sure, Socrates is subtly fostering Theodorus’s pride as he encourages him to regard his politically powerful detractors with serene detachment rather than anger. But it is Theodorus and not Socrates who proclaims, “[W]e who partake in this kind of chorus are not servants to the arguments, but instead the argu- ments are ours like household slaves, and each of them waits on us, to be finished whenever it seems good to us, for there has been set up over us neither juror nor spectator, as there is for the poets, to evaluate and govern us” (173c). Socrates, who will soon depart to answer his indictment in court, who reports that he has spent his whole life considering his defense at the bar of the city (Xenophon, Memorabilia 4.8.4; Apology 3), and whose own internal arguments are forever sternly demanding closer fidelity to the necessities of the arguments (e.g., 160e–61a, 163c–d, 195b–d, 200a–c), harbors no such illusion of freedom from necessity.

How important is this difference? Theodorus’s distaste for theoretical problems he cannot master is evidently what caused him early on to turn away from philosophy to geometry (165a), where he could enjoy the charm of precision and competence. Socrates’s more humble realism about his vulnerabilities, his limitations, and his ignorance allows him to understand philosophy as the activity of mortal, needy beings that it is, to keep in perspective why each question matters to us, and to focus on questions in proportion to their true importance for that endeavor. It is what equips him to be not just a student of this or that science but also a philosopher par excellence.

The Yearning for Self-Transcendence

Theaetetus is free of most of the vices we have seen. He has none of Protagoras’s vanity or greed; he makes no proud claims to be master of the arguments; he seems to share Socrates’s awareness of ignorance and his thirst to understand the highest matters.29 But so great is Theaetetus’s attraction to the self-transcending dedication to pure knowledge that this becomes a trap of its own. Despite Socrates’s ample warnings early in the dialogue that we have no access to knowledge of things “themselves in themselves,” despite extensive indications that knowledge is relational and that all the things we seek to know are embedded in an endless web of inter- relations that make perfect, exhaustive, and hence infallible knowl- edge of any of them impossible, Theaetetus proves profoundly attached to the hope that “itself through itself” the soul can “observe the common features of all things” and can thereby come to grasp being itself (185d–e). In this passage in which Socrates explicitly characterizes his activity as midwifing, observing that this is the way things also “seemed” to him (184b, 185e), Socrates encourages Theaetetus to let himself feel and acknowledge the hopes that Socrates himself once shared. Articulating this view is the next step Theaetetus must take now that the refutation of Protagoras has restored his confidence, because it does no good for him to proceed on a basis that denies or obscures his own deepest hopes and beliefs. These include the beliefs that knowing must be a pure activity of soul, independent of lowly perception, which allows the soul to grasp being itself and not just the world as it is for us, and that knowledge must be complete and unerring to count as knowledge at all.30 But on the basis of these opinions, the search for knowledge fails. If Theaetetus is to become philosophic, he must ponder well the reason for this failure rather than be offered solutions the merits of which he is not yet prepared to grasp. Yet it seems doubtful that he will. The attachment to pure knowledge for its own sake is in its own way as great an impediment to philosophy as the desires for fame and riches.

The Requisites of Hunting Well

If desiring knowledge for the sake of something else is a problem and desiring it for its own sake is a problem too, if pride is a prob- lem and diffidence is also, whatever does the proper pursuit of knowledge look like? Socrates describes the answer in fleeting glimpses, but he displays it throughout the dialogue. Especially helpful glimpses come at two rare moments when Socrates brings himself to the fore: when he asks and answers the question of what thinking is and when he asks and provisionally answers the ques- tion of what knowing is.

Asking if Theaetetus understands thinking as he does, Socrates gives his definition as speech that the soul itself goes through with itself about whatever it examines. Of course it’s as one who doesn’t know that I’m declaring it to you. For it looks to me that when it’s thinking it’s doing nothing other than conversing, asking itself questions and answering them, and affirming and denying. But whenever it has made a determination, whether more slowly or darting more quickly, and it now asserts the same thing and is not divided, we set that down as its opinion. So I at least call forming opinion speaking, and opinion a speech that’s been said, though not to anyone else or with sound, but in silence to oneself. What about you? (189e–90a)

This little exchange occurs just as Socrates is eliciting but Theaetetus is failing to notice the fact that Theaetetus himself holds contradictory opinions about whether all humans understand the difference between the noble and the base, a widespread confusion that keeps our moral opinions churning (cf. 189c, 190d), and it takes place just before Socrates introduces the very static image of knowledge as fixed imprints in a block of wax. Especially in this context, Socrates’s glimpse of his own thinking about think- ing makes clear that what is especially valuable is not the opinion that rests unquestioned but the process of questioning even what we ourselves can say with some confidence, weighing alternative answers to our questions and actively considering where our igno- rance lies—not the knowledge we think we have safely stored away, but the ongoing dialectic we engage in with others and even more with ourselves.

The second glimpse comes as Socrates is preparing to introduce the dynamic image of the aviary that follows the wax image. He proposes now “to do something shameless,” to offer a definition of what it is to know (to epistasthai), even though he and Theaetetus have not yet succeeded in defining knowledge (episteme, 196d). By changing the question from knowledge to knowing, Socrates suggests again that what matters most is not the quality of the opinions we hold but our activity of searching and reasoning and that knowledge is not the certain and secure possession Theaetetus wants it to be but rather an ongoing human activity, better called knowing.

But having asked an excellent question, Socrates give a terrible answer: knowing is not, as most people think, a having or holding of the undefined entity called knowledge but the possession of it, in the way we possess the umbrella we need in a rainstorm when it sits safe in the closet at home (197b). This definition allows Socrates to present knowledge as birds in a cage that are securely in the keeper’s possession even if he sometimes mistakes them in retrieving them, thus conforming to Theaetetus’s desire to think of knowledge as a firm possession while holding out the promise of explaining false opinion (199a–b). But once again, on this Theaetetan basis, the account fails. What Socrates impresses on Theaetetus is the strange conclusion from his premises that it must be possible not to know what one knows and to be ignorant precisely on the basis of knowledge (199d)—consequences that are intolerable for Theaetetus but in a certain sense surely true. What Socrates slips in and what is more deeply problematic is that if knowledge is a possession that can be retrieved either correctly or incorrectly, then retrieving it correctly is still only true opinion (199b–c).

The alternative way of understanding knowing comes to sight if we attend to the activity that is left just off stage and to the ques- tion Socrates twice asks but never answers. The activity is that of the hunter who captures the birds originally—a sharp-eyed, resourceful seeker on the tracks of what he desires and knows he lacks. The unanswered question is what we should call “the hunting down again” of what we have learned (198a), or the hunter’s “thor- oughly understanding these same things by taking back up the knowledge of each thing and holding it, which he’d possessed for some time but didn’t have at hand in his thinking” (198d). The answer can only be that this is genuine knowing: a clear, vivid, present understanding of experience, which we have made our own through hunting and which still requires attentive recapturing to be fully actualized. Everything once learned and not presently contemplated is only latent or incipient knowledge, ours only in a sense and subject to disintegration as the mortal possession of a mortal being that it is.31 To learn is to acquire not an object but a capacity for the future activity of recognizing and drawing connec- tions and conclusions.

In sum, rather than considering knowledge a certain kind of thing, we should be thinking about knowing as a certain kind of activity and about knowing philosophically as that activity pursued at the most fundamental level in the dogged, intrepid spirit of a hunter. The point is not to get oneself and one’s human, all-too- human needs and desires out of the way: non-needy humans would never acquire the bravery or the skill for the hunt in the first place. What is needed, rather, is to allow even one’s deepest yearnings to surface and to be in play—including the yearning for self-tran- scending contemplation of being itself in its beauty and its perma- nence that Theaetetus feels and that Socrates in the Symposium calls eros—and to query those yearnings. What is needed is to be bold and courageous and to query one’s own spiritedness and cour- age, to take pride in one’s skill and progress, but especially to take pride in being honest about one’s ignorance and to keep revisiting and welcoming challenges to the things that one thinks one best understands. And this is the chief reason Socrates is in this discus- sion at all. We sometimes wonder what Socrates seeks to learn in dialogues that tread what for him must be familiar terrain. It is true but not sufficient to say that knowing is a collective activity and that Socrates is generous. This dialogue suggests that whatever Socrates understands about understanding itself he understands only by querying it continually and testing it with others.

Thus it is little wonder that truly independent hunters are so few and far between, and even capable followers are in short supply. Especially for all of us who can at most hope to join as auxil- iaries in such a quest, another quality emerges in this dialogue as critically important: trust. Early on Theaetetus reveals that he has been hearing about the way Socrates entangles interlocutors in perplexity; and although he has been troubled by the question of what knowledge is that he has heard Socrates is wont to ask, he has kept his distance. This is the disclosure that elicits Socrates’s midwife story, which successfully draws Theaetetus back into the quest to define knowledge. But Theaetetus’s distrust runs deeper, for he needs repeated encouragement to trust that pursuing the biggest questions can bear fruit at all. Progress requires dogged- ness, especially since discoveries must be continually tested, but this doggedness itself requires trust that the effort is worthwhile, trust in a community of fellow inquirers, and above all trust in oneself. Without such trust we are all inclined to use our minds for anything at all rather than for honest inquiry into the most impor- tant things we hope we know yet fear we may never know.

Trust, so essential to the fabric of social life, requires in statesmen and democratic citizens alike a delicate balance of deference to authoritative opinion and expertise with a reasonable confidence in one’s own well-informed judgment. It is marred by too much deference, but even more by excessive cynical doubt. In the student of philosophy, it requires a different but equally delicate balance of respect for the opinion and knowledge of others with independent judgment. Theaetetus is not only too distrustful but also, he shows in his first exchanges with Socrates, too prone to overrate expertise and to overlook the importance of common- sense, pre-philosophic knowledge in giving us a genuine if imper- fect grasp of the world, from which all expertise must begin (144e–45a, 146c–d).

Finally, Socrates suggests in the last lines of the dialogue that a good hunter needs gentleness. As a result of this humbling conver- sation, he tells Theaetetus, if in future he is “pregnant” with knowl- edge, he will produce better offspring; if not, he will be less disposed to severity with those around him, gentler, and more moderate in not supposing he knows what he does not know (210b–c). This comment is surprising because Theaetetus appears in every way moderate and more prone to timidity than to harsh- ness. But not least among Socrates’s gifts is an extraordinarily gentle acceptance of limitations—those of himself, of his interlocu- tors, and of the extent to which he is able to satisfy his hopes, including hopes for perfect knowledge. Repeatedly we see Theaetetus rejecting answers that are imperfect but not unpromis- ing. Not all harshness is noisy, and harshness toward reason can infect even or especially its lovers.

Human beings do naturally desire the truth, but this desire is intimately bound up with more powerful desires that pull it off course, making deception, self-deception, hypocrisy, wishful think- ing, tendentious argument, prejudice, and cynical despondency the norms among us rather than the exceptions. Retreating from the dishonest contentiousness of contemporary politics to the purity of Plato’s dialogue on knowledge, we find ourselves thrown up against the dishonest contentiousness of even the brilliantly intellectual world of ancient Athens. But Plato warns us not to try to retreat into some realm of even greater purity; rather, he challenges us to reflect more deeply on our own natures and on how hard we must work to create and sustain the communities large and small in which human beings, with small faltering steps, can dare to look honestly for truth. Precisely the dialogue on knowledge shows why Socrates was first and last a political philosopher: wisdom is human wisdom about the world of our experience, at the center of which is always ourselves, not isolated minds or egos but political animals intensely involved with one another even in our most serious attempts to know.

Notes

1.         While the moral and political themes of the Theaetetus have been observed by commentators especially on the digression—e.g., David Bostock, Plato’s “Theaetetus” (Oxford: Clarendon Press, 1988); Rachel Rue, “The Philosopher in Flight: The Digression (172c–177c) in Plato’s Theaetetus,” Oxford Studies in Ancient Philosophy 11 (1993): 71–100—the close connection between these themes and the problem of knowledge has never been fully developed. Most relevant is Paul Stern, whose Knowledge and Politics in Plato’s Theaetetus (Cambridge: Cambridge University Press, 2008) shows how the dialogue defends the superiority of the philosophic life over the political life and attends to many of the obstacles to philosophizing well, among which he stresses the love of one’s own. I build on this account to argue that attention to the political, social, and moral aspects of the human knower is key to Socrates’s work in overcoming relativism and grounding philosophy altogether.

2.         The silence of Plato’s Theaetetus on the doctrine of forms, as on the related doctrine of the immortality of the soul and the recollection thesis, has been seized on by commentators as a key issue for understanding its status in the Platonic corpus. David Sedley in The Midwife of Platonism (Oxford: Clarendon Press, 2004), following Francis Cornford in Plato’s Theory of Knowledge (Indianapolis, IN: Library of Liberal Arts, 1957), treats this silence as a limitation of the Theaetetus, whose failure points us to the Platonic solution offered elsewhere, above all the Phaedo. By contrast A. A. Long reads the Theaetetus as both a repudiation of earlier “Platonist” doctrines and an indication of the limits of Socratic thought, written at a time of profound uncertainty: “Plato’s Apologies and Socrates in the Theaetetus,” in Method in Ancient Philosophy, ed. Jyl Gentzler (Oxford: Clarendon Press, 1998), 113–36. A third possibility is that these doctrines taken at face value were never Plato’s final word: Joe Sachs suggests, for example, that the Theaetetus works to “demythologize” the doctrine of recollection: Plato, Theaetetus, trans. with introduction and notes (Newburyport, MA: Focus, 2004), 8. I insist only on the value of trying to read the Theaetetus carefully on its own terms to see if it does not itself indicate compelling solutions to its own perplexities.

3.         As Robert Bartlett puts it, reminding us of Socrates’s claim to know nothing noble and good in the face of the city’s insistence that all decent citizens must know what is right, “The beginning and end of the Theaetetus should prevent readers from forgetting how politically and morally charged is the question ‘what is knowledge?’ if that question

is raised in a spirit of philosophic perplexity”: Sophistry and Political Philosophy: Protagoras’s Challenge to Socrates (Chicago: University of Chicago Press, 2016), 116.

4.         All translations from the Greek are my own. Commenting on this provocative exhortation, Joseph Cropsey writes, “It is Socrates’ purpose here as everywhere to teach the ethos of philosophy rather than its doctrines: unfailing perseverance that is capable of being strengthened by the goodness of the pursuit rather than defeated by the impossibility of consummating it”:

Plato’s World: Man’s Place in the Cosmos (Chicago: University of Chicago Press 1995), 35. I think Cropsey is right to focus on the question of ethos, though its merit becomes questionable if the pursuit fails.

5.         Sachs finds in all Plato’s dialogues, but especially in this one, “the beginnings of fruitful lines of thought” in abundance, requiring us to complete them if we are to make any progress: Theaetetus, 5.

6.         Cf. Plato, Republic 533b–c.

7.         Cf. Diogenes Laertius 9.51.

8.         Job Van Eck, in “Protagoras’s Heracliteanism in the Theaetetus,” Oxford Studies in Ancient Philosophy 36 (2009): 199–248, makes some progress in clarifying this claim by conceiving of “things” as just processes, but whether a process is conceivable without something that undergoes it remains a question.

9.         Stern notes the importance of potentiality for resolving the aporiai of this dialogue (Knowledge and Politics, 236–38, 284), as does Jill Frank in Poetic Justice: Rereading Plato’s Republic (Chicago: University of Chicago Press, 2018), chap. 6. I agree with Frank that Socrates is in deeper agreement with Protagoras than first appears and that Socratic knowledge turns out to be more deeply dependent on perception, experience, relationality, and intersubjective confirmation. Unlike Frank, however, I see, on one hand, no grounds for differentiating Protagoras’s position from the radical Heraclitean claim that there is nothing but motion and, on the other, no evidence that Protagoras was engaged

in anything like the intersubjective testing that is Socratic dialectics. Thus I find in Socrates’s critiques of Protagorean relativism the key to his defense of a human knowledge that is not merely “contestable, contingent, and fallible” (Frank, ibid., 207).

10.      Iliad 8.18–27. The allusion Socrates makes to this claim is indirect and even misleadingly reassuring: whereas Zeus boasts that he could with a “golden chain” lift the whole earth and all the gods to dangle in space, Socrates calls the golden chain the sun whose regular motion keeps the world safe.

11.       Diogenes Laertius 9.51; cf. Diels and Kranz (1952) 80B4. d s; Theaetetus

162d–e.

12.      Thus I concur with Bartlett (Sophistry and Political Philosophy, 201) that the challenge of mysterious gods may have been an important factor driving Protagoras’s radicalism, though unless Protagoras was confused, his positive intention could only have been to defend sophistry, not philosophy.

13.      See esp. Plato, Phaedo 96a ff.; Phaedrus 229c–30a; Apology 20c–24b; cf. Xenophon, Memorabilia 1.1.11–16.

14.      Sedley notes the parallels and allusions to the Apology in the midwife account, which Long (“Plato’s Apologies,” 122) considers an improved version of the defense offered in that work. For an illuminating account of the meaning of the Socratic turn in the Apology, see David Leibowitz, The Ironic Defense of Socrates (Cambridge: Cambridge University Press, 2010).

15.      R. G. Wengert observes the contradiction: “The Paradox of the Midwife,” History of Philosophy Quarterly 5 (1988): 3–10. Sedley outlines the extensive knowledge Socrates must have simply to perform his art of midwifing skillfully, though he treats this as an exception to Socrates’s greater ignorance in this dialogue (Midwife of Platonism, 33–35). While perfect ignorance and skilled midwifery are certainly incompatible, a different resolution is suggested by Socrates himself in his claims to have only “a certain human wisdom” (Plato, Apology 20d) and to be an expert “only in erotics” (Plato, Symposium 177d).

16.      Lewis Campbell, in The Theaetetus of Plato (Oxford: Oxford University Press 1883,) 28n, Sedley (Midwife of Platonism, 84–86), and Bartlett (Sophistry and Political Philosophy, 130–31) observe the latter suggestion. Ruby Blondell notes Socrates’s assimilation of himself both to the divine and to philosophy in The Play of Character in Plato’s Dialogues (Cambridge: Cambridge University Press, 2003), 273.

17.      The significance of these refutations tends to be overlooked by commentators on the digression, who take too much at face value the initial portrait of the philosopher as a naive innocent in political matters; see, e.g., Stephen Menn, “On the Digression in the Theaetetus,” Oxford Studies in Ancient Philosophy 57 (2020): 65–120.

18.      Bostock (Plato’s “Theaetetus,” 98) suggests that the chief purpose of the digression is as a pointer to the fuller arguments about justice in the Gorgias and Republic.

19.      See, e.g., Rue (“Philosopher in Flight,” 89–90); Sedley (Midwife of Platonism, 84); Stern (Knowledge and Politics, 177), following Aristotle (Nichomachean Ethics 10.6) and Plotinus (Enneads 1.2.1).

20.      I agree with Stern (Knowledge and Politics, 179) that this Homer reference raises the important question of humans’ belief in providential gods, but I would add that the key issue is the belief in avenging gods, which Socratic interrogations of justice address by showing that vice is pitiable and hence vengeance irrational.

21.      David Bradshaw thus seems right in arguing that a major function of the digression is to show that the clever man of the city proves inferior on his own terms to the philosopher, in a way parallel to Socrates’s refutations of Protagoras on his own terms: “The Argument of the Digression in the Theaetetus,” Ancient Philosophy 16 (1998): 61–68. Thus, to use a term Bradshaw does not, both are “dialectical.” It is notable, however, that the reasons for the political man’s dissatisfaction with himself are never stated. Bradshaw sees the only alternative to Protagorean moral relativism to be a moral absolutism according to which God is the measure, following Ronald Polansky, Philosophy and Knowledge: A Commentary on Plato’s “Theaetetus” (Lewisburg, PA: Bucknell University Press, 1992), 134–48. If Socrates is assimilating the human intellect to the divine, however, moral truth may have less the character of absolutes dictated from on high than of articulating what human thriving is on the basis of a deep and dialectically acquired self- knowledge.

22.      This argument has attracted considerable controversy. Gregory Vlastos, in his introduction to Plato, Protagoras (Indianapolis, IN: Library of Liberal Arts, 1956), and Bostock (Plato’s “Theaetetus,” 89–92) charge Socrates with unfairly omitting the qualifiers needed to acknowledge that Protagoras is conceding only what is true for others and is asserting only what is true for him. To this Edward Lee and E. K. Emilsson argue that Socrates is not so much refuting Protagoras as silencing him, showing that he has no good refutation of his own critics: Lee, “’Hoist with His Own Petard’: Ironic and Comic Elements in Plato’s Critique of Protagoras” (Theaetetus 161–71), in Exegesis and Argument, ed. Edward Lee et al. (Assen, Netherlands: Van Gorcum, 1973), 225–61; Emilsson, “Plato’s Self-Refutation Argument in Theaetetus 171A–C Revisited,” Phronesis 39 (1994): 136–49. Myles Burnyeat argues that Socrates is implicitly working from Protagoras’s own relativistic premises and that his refutation is decisive: “Protagoras and Self-Refutation in Plato’s Theaetetus,” Philosophical Review 85 (1976): 172–95. He reads the “man is the measure” teaching as affirming both that what appears to each is true for him and that what does not appear to each is not

true for him. Thus Protagoras’s claims require him to grant that all who disagree with him—most individuals and perhaps everyone if Protagoras is not serious about his own claims—are not the measure of what is and is not; Protagoras can escape this conclusion only by retreating into a solipsism that Burnyeat argues is humanly unsustainable. Gail Fine, by contrast, citing Aristotle, Metaphysics 4.5.1 and 11.6.1 (cf. also Diogenes Laertius 9.51), presents Protagoras not as a relativist but as an “infallibilist” who asserts that all views are true simply: “Protagorean Relativisms,” Proceedings of the Boston Area Colloquium in Ancient Philosophy, 11 (1995): 211–43; “Plato’s Refutation of Protagoras in the Theaetetus,” Apeiron 31 (1998): 3, 201–34. But an infallibilist must abandon the principle of noncontradiction, making nonsense of his own assertions, and Protagoras seems to have prided himself on his logic.

M. M. McCabe brings out the frequency of Protagoras’s appeals to nonrelativistic principles of reasoning in the speeches Socrates puts in his mouth: Plato and His Predecessors (Cambridge: Cambridge University Press, 2000), 38–39. Long suggests that Plato does this to underscore the impossibility of arguing for relativism without recourse to such arguments—but likewise the impossibility of refuting it without such recourse: “Refutation and Relativism in Theaetetus 161–71,” Phronesis 49 (2004): 24–39. But the point is that Protagoras becomes interesting only when he emerges out of his most radical relativism or solipsism, where he cannot stay, to make nonrelativistic claims about the world, which he cannot defend.

23.      On Protagoras’s pride see esp. Protagoras 335a. Lee (“Hoist with His Own Petard”) brings out Protagoras’s intense, proprietary, and prickly concern to advance his own teachings as Plato presents him here—to the point of being ready to come back from the dead to defend them. Devin Stauffer suggests that it is not so much Protagoras’s concern for honor as his lack of self-reflection about that concern that proves a decisive limitation: “Socrates and the Sophists,” in Recovering Reason, ed. Timothy Burns (Lanham, MD: Lexington Books, 2010), 110.

24.      Sedley (Midwife of Platonism, 58–59) points to the same problem in arguing that the Protagorean thesis includes no hierarchy of “levels” that allow him to include the worlds of others in the incorrigibly private world he affirms we each inhabit.

25.      Socrates indicates that Protagoras is not reflecting enough on these features of human experience when he asks Protagoras why he makes man the measure and not a pig or dog-faced baboon, or even a god (161c–d, 162c).

26.      Burnyeat, in The Theaetetus of Plato (Indianapolis, IN: Hackett, 1990), 24–26, brings out the way Protagoras in both Theaetetus and Protagoras is in fact slippery on whether his expertise consists in an ability to confer actual benefits or only to leave students with the belief that they are better off. It is telling that Protagoras evidently cannot stay with either. Stauffer suggests that this impasse may have been the motive for Protagoras’s relativism, that “unwilling and unable to renounce his view that the good consists in pleasure, he despaired of establishing that those who reject that view are mistaken, and he expressed the situation through his radical relativism” (“Socrates and the Sophists,” 111–12).

27.      I am indebted to Sedley for thus making sense of the examples in this passage and what he calls its “dense intertextuality with the Gorgias” (Midwife of Platonism, 88).

28.      Cf. Plato, Statesman 293a ff.

29.      Blondell, while noting all Theaetetus’s virtues, sees in him no corresponding limitations as an interlocutor and hence concludes that he cannot be blamed for Socrates’s failure: Play of Character, 260.

30.      David Bolotin elucidates this dynamic well in “The Theaetetus and the Possibility of False Opinion,” Interpretation 15 (1987): 179–93. Stern observes the importance of the reference Socrates makes here to his own earlier hopes, but frames Socrates’s revision of them only as a recognition that we have no access to pure knowledge “untainted by particulars” (Knowledge and Politics, 37). I think the Theaetetus suggests more radically that we have no access even to particular beings in themselves, but only to a relational world of beings as they are for us.

31.      Cf. Plato, Symposium 208a; Xenophon, Memorabilia 1.2.21 and 23; Aristotle, Nicomachean Ethics 7.3.