BMCR 2009.05.43

Knowledge and Self-knowledge in Plato’s Theaetetus

, Knowledge and Self-knowledge in Plato's Theaetetus. Lanham: Lexington Books, 2008. ix, 183. ISBN 9780739125731. $65.00.


Structuring her book as a reading of the Theaetetus, Tschemplik intends to “examine the interconnected questions of knowledge, self-knowledge, and the limits of knowledge in Plato” (1). This examination provokes some interesting further questions: How might mathematical knowledge differ from other forms of knowledge in its dependence on the investigator’s self-awareness? How might appreciating his “knowledge is perception” hypothesis require Theaetetus to understand his own soul? How might the birthing of intellectual ideas require a technically adept helper?

In pursuit of questions like these, the majority of Tschemplik’s book takes up Socrates’ examination of Theaetetus’ three definitions of knowledge, in significant part by discussing cognate passages in the Symposium, Charmides, Republic, and other dialogues. The book’s angle is to take a work best known for its analyses of knowledge, observe its aporetic conclusion, and suggest a new reason for that impasse: Theaetetus fails not in ignoring “the forms,” for example, but in ignoring the importance of self-knowledge. This is a provocative and appealing thesis. But Tschemplik’s book makes an insufficient case for it. It is not for overwhelming counterevidence that it doesn’t succeed; indeed, aspects of its central claim seem true, and readers of Plato are hereby enjoined to read the Theaetetus for its lessons about self-knowledge. The problem is instead that the absence of any sustained exposition about self-knowledge, impatience in argumentation and close reading, and overly-quick resolution of interpretive problems by reference to parallel texts, plus much haphazard prose, prevent this book from clarifying and substantiating its claims.

Tschemplik is very justified in making another go at the problem of self-knowledge in Plato. The matter is crucial to the history of philosophy, the epistemological issues are difficult, and Socrates’ remarks about it in the Phaedrus, Apology, First Alcibiades, and Charmides still need unpacking. More specifically:

1. At Apol. 28e and 29d Socrates glosses the way he philosophizes all the time as an examination of himself and others; this, combined with his realization that he knows that he knows nothing big ( Apol. 21d), his claim to be preoccupied with knowing himself ( Phdr. 229e), and his recommendation of self-knowledge before self-cultivation ( Alc. I 129a), suggests he equates philosophizing with knowing oneself. But not every philosopher so explicitly makes this equation (in Plato: Apol. 23d4, Tht. 143d4, Soph. 213a5, Phdo. 61c6 and passim, etc.). So why is Socratic philosophizing so attentive to self -knowledge? Why might (or do) others think getting wisdom doesn’t require such direct awareness of oneself?

2. By the fourth century Greek philosophers debated whether getting self-knowledge would depend on getting knowledge about one’s personal self or instead about the soul in general or even of god in particular. One might call the two views the “Romantic” or “individualizing” view (“who am I?” “how am I unique ?”) and the “Psychological” or “generic” view (” what am I” “in what way ought I not to be unique?”). How might we understand Socrates’ claims by means of these distinctions?

3. Asking “What is it to know?” may lead to a range of answers; it may not be the same activity or state to know x as it is to know y (where, e.g., x = a geometry solution, and y = the self). Knowledge of the self is a likely candidate for one species of knowledge; what might this species’ differentia be?

These questions are only three out of many others (e.g., “what are the most effective ways of getting self-knowledge?,” “how do we know when we have it?,” etc.), each of which could serve as a capacious dialectic for a monograph. What’s surprising about Tschemplik’s book, however, is that it never gives undivided attention to any of these or other puzzles about self-knowledge. The reader is obligated to bring his or her own curiosities and to see whether anything Tschemplik says speaks to them. (Given this, it is unfortunate that “self-knowledge” is not in the index,1 and is hardly in the bibliography.2) Still, the following summary tries to bring out the ways in which Knowledge and Self-knowledge in Plato’s Theaetetus could speak to someone’s curiosities about self-knowledge in the dialogue.

Tschemplik’s brief introduction includes her most systematic remarks about self-knowledge:

We must… rid ourselves of the usual modern conceptions of self-knowledge which… are associated with intensive introspection…. Socrates presents his quest for self-knowledge as a task that necessarily involves other interlocutors who are willing to engage in dialogue with him…. He is concerned with finding out what kind of person he is…. The kind of life that someone leads is the best indication of who she is…. Both in the Republic and in the Phaedrus Socrates presents his listeners and readers with images of the soul that clearly indicate that it is complex… which presents for us the challenge of living a harmonious life. Socrates’ question regarding self-knowledge is best understood as an ethical one. (4-5)

Not all of these issues recur: there is no detailed argument about the failure of the modern conception of self-knowledge; or of the reasons Socrates presents, to the extent he does, for thinking of self-knowledge in one way rather than another; or for the benefit of thinking of self-knowledge as mainly an ethical inquiry. But a two-page outline of the book’s chapters (8-9) does succeed at pointing approximately to the issues to which Tschemplik will return.

The first chapter, “Framing the Question of Knowledge and Self-Knowledge,” compares Euclides’ narration in the Theaetetus with Socrates’ narration in the Charmides and Apollodorus’ in the Symposium. Its principal goal is to show what the narrative frames in the Theaetetus“force” (34) us to realize about knowledge and self-knowledge. Tschemplik does not argue that we draw identical conclusions thinking about the frames as we do thinking about Socrates’ examination of Theaetetus’ definitions, but the implication is that the two overlap. The sense is, I think, that the early part of the dialogue acts as an overture, priming us to see what the rest is about. Four of Tschemplik’s claims deserve particular attention.

First: reports of conversations are uncertain because narrators are unreliable (12, 34). Tschemplik appeals for this claim to the odd and well-worth-studying conversation, full of remarks about forgetfulness and verification, between Euclides and Terpsion, the reporter and auditor of the conversation between Socrates, Theodorus, and Theaetetus. Yet it does not seem to me an insight into knowledge that witness or messenger testimony is in principle open to doubt, but into the trustworthiness of testimony. Nor does Tschemplik vindicate this insight by ever doubting anything Euclides reports.3

Second: a frame “calls into question the possibility of objective accounts… [since] everything said or written carries with it the burden of perspective” (8). It is smart to consider who a person is before accepting their claims to knowledge, but it’s hard to see how the frame itself, and thus the early part of the dialogue, reminds anyone of this. The lesson cannot be for Theaetetus, since he is dying out of earshot during Euclides’ report. Nor does it seem useful for Plato’s readers, since a depicted conversation, with or without a frame, should suffice to point out that each speaker might have his own perspective.

Third: in the frame conversation Euclides says he edited the manuscript he has read out for Terpsion; he hints that he’s hiding the report’s essential subjectivity (17). Tschemplik’s idea that “Euclides cannot learn anything about himself from his writing” (35) is an interesting one, but not apparently a consequence of the kind of editing he’s done. After all, even if both he and Terpsion could forget that he could be an imperfect stenographer, the obscuring of subjectivity would seem to come only from the deletion of observer-indexing words such as ” I think he said,” not from the deletion of speaker-indexing words such as “he said,” as it was in this case (143c).

Fourth: “the frame reveals what the dialogue proper conceals, namely, that the mathematician is a man, a human being” (21). Euclides and Terpsion might indeed come to understand better the meaning of the conversation Euclides reports if they realize that Theaetetus has been mortally wounded in war. But the dialogue does not make obvious what could be the connection between Theaetetus’ interests in 399 and his death serving the Athenians. It is worthwhile to speculate on possible connections.4 But I’m not sure Tschemplik does speculate in a way that could make the frame’s revelation of Theaetetus’ humanity particularly telling: after all, despite claiming that “Theaetetus the mathematician… seems to have no concern for his or any other city” and “strenuously avoids bringing up any political matters” (21), for which Tschemplik provides little evidence, Socrates’ interest in Theaetetus seems sufficient to establish for the auditor or reader his young friend’s humanity.

Obviously the narrative frames, and Tschemplik’s discussion, do raise important questions about observer-bias and the salience of viewpoints. But it’s hard to see that they enter into an understanding of knowledge and self-knowledge in the robust way these must matter to Socrates and Plato.5

The second chapter, “Intellectual Midwifery, Intellectual Pregnancy,” aims to argue for the claim that “self-knowledge is the analogue of self-procreation: Just as procreation requires an ‘other,’ so too does self-knowledge” (41). This fruitful analogy is marred by its defective formulation and is inadequately harvested. While Tschemplik concludes that “Socrates’ explication of midwifery … explains why philosophy is dialectical and must be in the form of dialogue” (53, cf. 60, 50), she does not provide that explanation, either in conceptual or causal form; nor does she consider potential opposing views—a problem less because there are devastating opposing views than because it’s hard to be really convinced without reading some play of criticism and rejoinder.

The third and fourth chapters explain why Socrates takes his time examining his interlocutor’s three proposed definitions of knowledge. The first of these, “Perception and Knowledge,” works carefully through the Protagorean and Heraclitean views of knowledge and is, because of its sensitivity to details of the argument, the most successful of the book. Tschemplik writes that “we must pay particular attention to the way in which Socrates guides Theaetetus toward the discovery of soul, leading him from the realm of the visible to the invisible” (67, 68). Socrates wants Theaetetus to see what his first suggested definition comprehensively entails about subjectivity and metaphysics (70), rather than straightaway making for him a distinction between sense-organs and that which uses those sense-organs, i.e., the soul (96-7). The following chapter, “Doxa-Logy,” presents the remaining definitions of knowledge and the wax-tablet and aviary thought-experiments.

The fifth chapter, “Mathematics and Beyond,” works to support Tschemplik’s hypothesis that “the purpose of the dialogue is to explore the mathematician’s understanding of knowledge and to consider whether it is a possible paradigm for philosophical knowledge[,] and that the aporetic conclusion of the dialogue is an indication that philosophy is not reducible to mathematics” (141). This is a stimulating hypothesis, one that could explain why Plato wrote several dialogues featuring mathematicians or math-appreciators (e.g., Glaucon). Several times through the book Tschemplik had alluded to the possibility that “knowledge” ( epistêmê) and “wisdom” ( sophia), the pair of terms introduced by Socrates near the dialogue’s beginning (145e), are importantly distinct: the former, the object of definitional inquiry in Tht., stands in for mathematical knowledge; the latter, for philosophical knowledge.

Tschemplik begins the chapter by observing that, unlike math problems, philosophical problems are not answered systematically; but this is not the tack Tschemplik takes; in fact she mostly ignores concrete methodological questions. She instead turns to the Digression ( Tht. 172c-177c) and to Rep. VI-VII. The Digression-philosopher, Tschemplik observes, lacks self-knowledge and interest in his neighbors—and is peculiarly like Theodorus—but, confusingly enough, is supposedly concerned with human beings in the abstract. This is confusing because it sets him off from those Protagoreans who without examination take human beings to be the “measure” (142-6). (I am not sure, however, what the reader is to conclude about the Digression-philosophers.) Tschemplik continues to the Republic. The first part of her analysis points out that the Line analogy is mathematical in that it omits the Good. Put another way, the Republic treats mathematics as a good training tool but also as a pursuit that fails to examine its starting points; it blurs the distinction between subjective hypotheses and objective archai (148-55). The second part of Tschemplik’s analysis of the Republic“read[s] Socrates’ education of Theaetetus as illustrating the ascent out of the cave.” While the prisoner, even upon being liberated, seems to take whatever he sees as true, the cumulative effect of seeing a range of environments seems adequate for bringing him to realize that perceptions cannot always be trusted: “the ascent leads the liberated prisoner to see the multiplicity of perspectives and thus gives him a perspective on perspective” (159). The chapter ends with Tschemplik’s clearest summary of her book’s findings (160-1).

In a short conclusion to her book, Tschemplik says that while the Theaetetus shows the difficulty of defining knowledge, it still “provides the main ingredients that make up our knowledge of the world: perception, opinion, and logos” (165). This kind of conclusion, as well as others Tschemplik makes, makes a nice response to the silly view that refutation must either be wholly negative and preparatory or present ground in which to search for the right answer that Plato has hidden within. Unfortunately, this nice response is partially unearned: the book did not much assess other candidates for constituents of knowledge. And so when Tschemplik goes on to say that we’re to wonder whether these three ingredients are also appropriate for knowing ourselves, I feel my agreement is too strong: I wonder why we didn’t get clearer earlier about whether they are appropriate or not.

Overall, Tschemplik never fully justifies the importance of thinking about “self”-knowledge. Many kinds of knowledge are important to understanding the world and living in it well: there is knowledge of one’s position; there is knowledge that reports can be wrong; there is knowledge that the act of observing can affect one’s observations. But are any of these some special “self-knowledge”—the things the Delphic inscription commands one get—or are they simply facts that any epistemically-mature person needs to know, akin to realizing that things look smaller the farther they are away, and that the sun-spots in one’s eye are temporary? If these are self-knowledge, then what’s the big (philosophical) deal? One needn’t doubt that they could be philosophically important to want to know how. Is the mathematician who doesn’t distinguish knowledge of geometric proofs from knowledge of herself making a common mistake, or is she being implausibly obtuse, or does she even have a richer epistemic attitude toward those proofs than we had thought? I ask these questions because if Tschemplik means to show that Socrates’ lesson is that self-knowledge is a precondition for knowledge (of other things), then it’s important to know what exactly this precondition amounts to, how difficult it’d be to fulfill that precondition, and whether it seems to us true that there is such a precondition.

I should also make a comment about Tschemplik’s authorial methodology. Her self-proclaimed “dramatic” approach (1, 6, 11-13), which I suspect means paying close attention to everything that happens in the dialogue, and which is carried off with mixed success,6 is seriously weakened by her “interdialogic” approach (167). The latter encourages her to switch between dialogues too readily. Rather than imagining possible reasons for Socrates or Theaetetus to have said something, and then eliminating the wrong ones by appeal to context or validity or character, too frequently she leans on what she takes to be a cognate passage in some other work. Yet the cognate passage—often in itself quite intriguing—tends to be dealt with as cursorily as the target passage, usually mined for utterances made by Socrates. The reader is left with more, or the pre-existing, puzzles.


1. Surprisingly, “conversation,” “Delphic Oracle,” “expertise,” “interdialogic approach,” “knowledge,” “Know Thyself,” “philosophy,” or “talking,” aren’t in the index either, though all key to understanding Tschemplik’s thesis.

2. The closest are Charles Griswold, Self-Knowledge in Plato’s Phaedrus (Yale, 1986) and Mary Margaret McCabe, “Looking Inside Charmides’ Cloak: Seeing Others and Oneself in Plato’s Charmides,” in Maieusis, ed. D. Scott (Oxford, 2007). There are not really any works on ancient or modern conceptions of the self, either.

3. Tschemplik’s terminology in this section is confusing, as she sometimes refers to the part of the conversation directly concerning the definition of knowledge “the dialogue.” Her terminological missteps lead her to claim absurdities such as “Plato abnegates responsibility for the dialogue by identifying Euclides as its author” (60, 166). This is false: in the fiction of the dialogue, Euclides takes responsibility for the report of the conversation between Socrates, Theodorus, and Theaetetus, but everyone knows that Plato is responsible for the conversation between Euclides and Terpsion, and thus ultimately for the earlier one as well. One solution might have been to have called the work Theaetetus the dialogue (“dialogue” as the name of a literary genre); the conversation between Euclides and Terpsion “the later conversation” or, if the term “frame” is important, “the framing conversation”; the part of the conversation between Socrates, Theaetetus, and Theodorus before Socrates asks for a definition of knowledge “the beginning (or non-definitional) part of the earlier (or Socratic) conversation”; and the part of that conversation after the first request for a definition “the definitional (or long) part of the earlier (or Socratic) conversation.” Or she could have spoken of Plato’s dialogue and Euclides’ dialogue and the pre-examination part of Socrates’ conversation and the examination part of Socrates’ conversation.

4. A recent book that tries to make connections is Paul Stern, Knowledge and Politics in Plato’s Theaetetus (Cambridge, 2008).

5. Very useful on the framing devices is Kendall Sharp, Socrates and the Second-Person: The Craft of Platonic Dialogue, Ph.D. diss. (Chicago, 2006).

6. I give just three examples of places where this type of reading seems to falter. First, despite wanting to read Theaetetus with other dialogues, she gives a general dismissal of the relevance of the Sophist and the Statesman (16). This exclusion seems unprincipled, in particular on “dramatic” grounds. Socrates’ initiation of the conversation about philosophers and sophists with the Eleatic; his recommendation of Theaetetus as the primary interlocutor in the Sophist; and his claim to Theaetetus to have listened to all his answers ( St. 258a) all seem as or more informative to the matter of self-knowledge in the Theaetetus as do Socrates’ actions and discussions with people other than Theaetetus in other dialogues. Second, Tschemplik’s commitment to this kind of reading often wavers. Early on she specifies what ” Plato… alleges” (5); no doubt Plato has all kinds of goals in writing his dialogues, many of which close reading will recover, but it hard to see the dialogues as “erotic and maieutic, seducing the reader into giving birth to ideas” (61) if we ignore who is saying what. Third, there are important insensitivities to tone; one instance is when Tschemplik claims that Theaetetus “avers” (70, re: Tht. 151e) something when in fact he seems simply to be suggesting it.