One can hardly throw a stone into the field of Platonic scholarship without striking some controversy or other. Perhaps the safest thing we can say is that Plato presents his Socrates as the paragon of the philosophic life, the examined life, the antithesis of which he famously rejects as unlivable. But what counts as an “examined life?”

In his defense against the capital charges for which he was tried and executed by the Athenians, Plato’s Socrates leaves little doubt that his own way of life was without precedent or parallel. He denies both that he pursued the impious study of natural science (seeking knowledge of natural causes and necessities that would contradict the city’s official religious doctrines) and that he made his living as did the sophists, who were notorious for corrupting young men by debunking the political community’s demands for virtuous devotion. But in his last conversation, on the day of his death, Plato’s Socrates gives the lie to his courtroom testimony by describing his youthful passion for the scientific investigation of nature. What then of his denial of having been a sophist? How would we justly characterize the difference between Socratic philosophy and the art of sophistry?

This is perhaps the most important question that Robert C. Bartlett helps us to answer in Sophistry and Political Philosophy: Protagoras’ Challenge to Socrates. By means of an elegantly expressed and utterly meticulous line-by-line interpretation of Plato’s Protagoras and the first half of his Theaetetus, Bartlett brings to life Plato’s juxtaposition of the great philosopher Socrates and the great sophist Protagoras, who was arguably the Platonic Socrates’ most impressive conversational opponent. By illuminating this juxtaposition as he does, neither exaggerating nor minimizing the distance separating sophistry from philosophy, the Behrakis Professor in Hellenic Political Studies at Boston College provides invaluable assistance to the student or scholar who seeks a greater understanding of the questions and insights at the center of the Socratic life. What’s more, he does it with style and wit as well as thoroughness and precision, coolly untangling the maddeningly circuitous dialectic on one page and revealing Socrates’ wry, ironic humor on the next.

The selection of texts is straightforward enough. Protagoras, Bartlett argues, is “the Platonic dialogue treating the sophist” (emphasis in original), and the Theaetetus is a kind of sequel, since in it Socrates rehabilitates the argument of the by-now-long-dead Protagoras, giving it a fuller elaboration and defense than the man himself ever did. Bartlett begins, therefore, with three chapters interpreting the Protagoras, in which a relatively young Socrates refutes the rather older and quite famous sophist’s account of virtue before a crowd of intellectuals and aspiring statesmen, and moves on to two more analyzing the Theaetetus, in which Socrates, apparently indifferent to his looming public trial, examines before eventually discarding the Protagorean account of knowledge with some promising young mathematicians and their teacher.

Bartlett leaves virtually no stone unturned in his analysis of these texts. Every detail of any significance receives some attention and is woven into his broader interpretive account. Sophistry and Political Philosophy can therefore serve as a useful reference for anyone who, in studying the dialogues treated here, is seeking a cogent explanation for some dramatic detail or Socratic remark that has come to seem absolutely resistant to coherent interpretation.

But one will receive the greatest benefit from the book if one reads it with care from cover to cover and, above all, with the relevant Platonic dialogue open beside it and fresh in one’s mind. Bartlett, who has published more than one essay on Socrates and Protagoras, and who has even produced an excellent translation of the Protagoras in 2004, unfolds here a complex and complete interpretation that has been many years in the making. The argument is therefore laid out with the careful intention of a good teacher, whose initial and provisional account of a question or problem is often refined and developed on the way to his last word.

Bartlett’s overarching goal appears to be an elucidation of the alternative to Socratic philosophy presented by Plato through his depiction of Protagoras’ arguments and way of life. That way of life is famously presented by the Platonic Protagoras himself as the life of a sophist—a novel and shocking self-designation since, as Protagoras admits, none of his sophist predecessors or contemporaries has ever presented himself as such. This circumspection on the part of all sophists but Protagoras, the “cloaks” in which they have veiled their actual opinions and activities, they have deemed necessary on account of the ire of the Greeks that would fall upon them if their deepest reflections and teachings on virtue, politics, law, and the gods were publicly declared.

And yet, as Bartlett points out, Protagoras himself is hardly in the habit of blurting out his controversial opinions regarding nobility and political virtue. Rather, his claim of total frankness is itself a cloak for what is most incendiary in his teaching, and not the only one that Protagoras employs. Bartlett reveals with clarity and force the underlying meaning of the “myth” with which Protagoras regales his audience: that the notion of Zeus has been concocted for the political purpose of holding cities together by instilling in their citizens the fear of divine punishment; that belief in the Olympian gods generally provides human beings with the comforting but delusional assurance that the cosmos is hospitable to and supportive of human life; and that all of “political virtue,” the principles of character and action that cities compel their citizens to adopt, is justified only by incoherent explicit and implicit arguments in the minds of the devoted citizens themselves.

These subversive teachings are, however, masked by the myth’s complex structure and nominal orthodoxy. Apart from Socrates, only those in Protagoras’ inner circle who themselves seek to learn his art of sophistry are keyed in to the true meaning of his public speeches and displays. For the others, Protagoras is willing to provide educations that penetrate to varying levels of practical and theoretical understanding, but always at a price that rather famously favors the great sophist.

Protagoras has calculated that, by broadcasting the fact that he is a sophist, he can pursue gains that would be out of reach for his disguised colleagues, even or especially if he does so in such a way as partially to obscure what is most seriously at stake in his sophistic teaching. This calculation, however, carries a calculated risk: it exposes Protagoras to no little danger in professing to belong to the widely despised class of the sophists, and, as Socrates would be sure to insist, it would be sheer folly to brave such a risk without some assurance that one has correctly identified what it is that is worth pursuing in human affairs—that is, the human good.

Now, Bartlett quite ably and compellingly shows in his reading of the Protagoras that Protagoras is a hedonist. But to establish the prudence or choice-worthiness of the particular hedonistic life Protagoras has chosen to lead is not trivial. Not least of all, one must refute the claims of those who insist upon the existence of precisely those powerful deities whose existence Protagoras denies—deities who are generally said to punish indifference to moral virtue in the selfish quest for one’s own pleasure. That is to say, what is implied by the Protagorean way of life, as made evident through the Protagoras, is in need of theoretical justification.

It is Bartlett’s contention that the defense of the Protagorean maxim that “[a] human being is [a] measure of all things,” articulated by Socrates on behalf of the late Protagoras in the Theaetetus,  is an attempt to spell out what would have been Protagoras’ theoretical strategy in disposing of the problems presented by claims to divine revelation. (Brackets in the original.) To see this, we must untangle (among the many bewilderingly abstruse constructions in the Theaetetus and its sequels) this “human being is the measure” doctrine from two other, distinct hypotheses attributed in varying ways by Socrates to Protagoras in the course of his conversations with Theaetetus and Theodorus.

There is, first, the claim that knowledge is perception, which helps in accounting for the apparent relativity of sensory experience. For example, a wind isn’t absolutely hot or cold, but can be known as one or the other only according to the perception of a given individual. Secondly there is the “motion thesis.” This thesis describes the whole as a great “flux” of “becoming” in which enduring “being” has no place. It is a philosophic account of the origins of our experience according to which the objects of our conscious awareness emerge at every moment from an interaction between the active and passive powers of perceiver and perceived. A form of the latter, Bartlett claims, can be advanced as an explanation of the overwhelming empirical evidence supporting the former—a move that has indeed been favored by virtually every philosopher (and many poets) aside from the Parmenidean monists, difficult moral consequences notwithstanding.

But Bartlett argues that Protagoras is different from all the rest in one crucial respect. While it seems that one cannot help but admit that the human good must somehow remain “outside of the flux”—no one’s “perception” of arsenic as promoting robust good health can pass for knowledge —Protagoras was truly unusual in his attempt to include even the good in the flux of becoming, to make “a human being” the “measure” of even this. This surprising decision is apparently Protagoras’ attempt to deal with the claims of the “prophets” and “diviners,” that is, of those who lay claim to a form of knowledge the substance of which, if true, would constrain even a hedonist to live according to its prescriptions. The philosophic strategy for dealing with the theological challenge adopted by Protagoras is—at least, according to Socrates—to insist on a relativism so extreme that it destroys the very possibility of philosophy.

It goes without saying that such a philosophic position is inherently difficult to maintain, and Bartlett does not leave out of account the so-called “self-refutation” argument to which it is evidently vulnerable, to which Socrates himself points, and which has been the focus of many previous scholarly analyses. However, Bartlett is ultimately interested in more than whether Protagoras’ position is logically self-defeating. He seeks to show in addition what the crucial distinctions are between Socrates and Protagoras, since Socrates too made the theological challenges to the possibility of philosophy a central concern. That is, Bartlett rightly pays attention not just to the general form of Protagoras’ relativistic doctrine, but to its specific content and purpose, and therein finds the crux of the confrontation between Protagorean sophistry and Socratic political philosophy.

As a result, he is particularly enlightening in revealing what amounts to the moral and intellectual prejudices that underlie Protagoras’ position and teaching. On Bartlett’s reading, the concluding sections of the Protagoras demonstrate that, while the great sophist’s privately (if not publicly) avowed position on morality is an egoistic rejection of noble devotion or noble sacrifice as serving the good of the city but not the individual, he continues unbeknownst to himself to admire the noble courage of soldiers who march toward battle, struggle, pain, and even death.

Socrates, by pressing Protagoras to describe and evaluate courage and cowardice on the basis of the latter’s hedonistic principles, finally elicits from him an indication that he simply cannot hold to a view that fails to acknowledge the admirableness of courageous devotion. He is too attached to his own manly, spirited boldness; to the daring he exhibits and relishes in openly proclaiming himself a sophist while covertly carrying out a subversive project right under the noses of the cities whose sons he recruits; and to the courage he fancies he employs in holding to his harsh view of nature and the human condition.

Protagoras’ lack of self-knowledge concerning the character of the noble is partially a result of his failure to give adequate consideration to the opinions of “the many,” opinions which, as Bartlett duly notes, Socrates made the subject of much careful examination. Hence, Bartlett argues that Protagoras is guilty of a certain “moral obtuseness” that has rippling effects through his thought and career. Most important, this obtuseness appears to have short-circuited Protagoras’ investigation into the character of piety and thus of the category of human experiences that form the basis of religious belief.

Bartlett notes for example that Protagoras, unlike Socrates, fails to take seriously the question of the relationship between justice and piety. Socrates, who saw more clearly and deeply what binds justice and piety together, or where piety fits in with what is “by nature just,” considered more carefully the erotic hopes and mortal fears to which they respond and contribute. As a result, Socrates understood more clearly than Protagoras that there is more to piety, and thus to claims of divine revelation, than the city’s need to establish order through religious terror.

Protagoras therefore rushed to his relativistic rebuttal against religion without an adequate understanding of what he was trying to rebut. The atheism he tries to defend, at the expense of philosophy itself no less, is “unearned,” Bartlett argues, as is often the case with the atheism of  “the clever.” Since Socrates proves to have a subtler grasp of the psychology of piety and morality than does Protagoras, he even proves to be superior in precisely what Protagoras professes to teach best: the art of political persuasion.

As with all interpretations with the scope and depth of Bartlett’s, the reader is bound to find some points at which plausible alternative hypotheses seem to stand unrefuted or unaddressed. Perhaps the most significant one that emerged from my own reading concerned the character of Protagoras’ unexamined admiration for and attachment to nobility.

Bartlett emphasizes the fact that Protagoras’ objection to Socrates’ reduction of courage to the prudent pursuit of pleasure comes in the form of his insistence that, while the courageous “are willing to go to war,” the cowards “are not willing.” According to Bartlett, this reveals that “Protagoras cannot in fact or in the event stomach the reduction of courage”—a virtue which he “here senses or recognizes . . . comes into its own above all in war”—“to (an aspect of) selfish calculation.” This despite Bartlett’s having claimed, not long before, that in Protagoras’ view, what “usually goes by the name ‘noble courage’ is in fact an unwise (‘mad’) habituation to obedience . . . exercised especially in the face of the grave risks the city compels citizens to take” and that therefore “[t]he many admire as noble what Protagoras regards as insanely excessive daring.”

To be sure, this is precisely Bartlett’s point: that only under the pressure of Socratic refutation is Protagoras’ admiration for the courage of “cavalry men and peltasts” (from which he believed himself liberated) revealed. But must we necessarily say that Protagoras, who throughout the dialogue is reluctant to be perfectly straightforward, especially about his hedonism, is at this moment letting slip so simple a contradiction in his thinking?

Protagoras appears to have dedicated much of his career, by now quite long, to a cold-hearted critique of “political virtue”—to an analysis of precisely the soldier’s “error” in believing that his good lies in glorious death on the battlefield. It seems to me that Bartlett is more persuasive when he points to Protagoras’ inadequately examined love of his own courage or boldness than when he draws the conclusion that Protagoras has never noticed in himself, in his many decades of debunking the goodness of nobility, that he nonetheless continues to be stirred by the noble sacrifice of the courageous soldier.

But this kind of interpretive question merely shows what is so enriching about Sophistry and Political Philosophy. Bartlett is forceful and persuasive in his analysis, and an invaluable guide to the themes that prove to be of the greatest importance in Plato’s presentation of the confrontation of Socrates and Protagoras. This study takes its bearings at once from the most careful examination of the Platonic texts and from a serious consideration of one’s own thought and moral psychology, and so it only invites ever deeper and more probing analysis, and opens new and pointed questions even as it helps the reader to answer old ones. For just this reason, we hope that Bartlett continues to provide the scholarly community with his instructive and challenging approach to Socratic philosophy, since the questions with which he leaves us are no less in need of illumination than those he resolves.