The thesis of this relatively concise monograph is not entirely clear. In the introduction, the author announces her aim to show that “ Theaetetus. . . is a philosophically sophisticated elaboration of Apology that successfully differentiates Socrates from the sophists” (2). This is puzzling in regard to both dialogues. There is but one passing mention of sophists in Apology. In Theaetetus we do find Protagoras referring indirectly to himself as a sophist, but this dialogue, as the author notes, is a “systematic enquiry into the nature of knowledge.” It is not obviously an effort to differentiate the practices of the self-declared “barren midwife” Socrates from the sophist-as-relativist. In any case, one would like to have seen an effort by Giannopoulou to show that Apology is intended to focus on Socrates’ anti-sophistic credentials. But there is in fact hardly any discussion of that dialogue throughout this book. In addition, her intention to show the “thematic interconnectedness” between the two dialogues (3) must face squarely the difficulty that many would argue that Theaetetus belongs to a later phase of Plato’s development wherein Socratic philosophy has been superseded by something else. I share Giannopoulou’s disinclination to this view, but that certainly does not justify her in ignoring it. Finally, her attempt to bracket the two dialogues as somehow offering a unique account of Socrates’ philosophical practice founders on the obvious counterexample of Philebus. How is it exactly that Theaetetus marks Socrates’ “figurative death” (4)?
The author claims that “Socrates’ defense-speech [in Apology ] serves as the subtext which informs his explorations of knowledge in Theaetetus ” (3). This is far too vague to be of any use and is not made less so by her concluding claim to have provided evidence for “the interpretation of Theaetetus as a dialogue that has affinities with Apology ” (185). I am more than willing to accede to the “subtext” claim as well as to the “affinity” claim so long as Giannopoulou agrees that this will work for any two dialogues that one may randomly point to in the table of contents of the complete works of Plato. It is hard to resist the impression that by the time she comes to the end of the book, the author has herself lost heart in her desire to show how a certain reading of Apology adds substantively to the interpretation of Theaetetus.
Setting aside the forced attempt to relate Apology and Theaetetus, this monograph is a mostly sensible and sometimes insightful analysis of the arguments that make up the bulk of the latter dialogue. But the author’s intermittent resolve to try to bring Apology and Theaetetus together often leads her astray. For example, Giannopoulou embraces early on the view of Myles Burnyeat that “Platonic metaphysics” is absent from [ Theaetetus ] (13). And yet when young Theaetetus offers his first definition of knowledge as sense-perception, Socrates clarifies the task they are facing by stating that the correct definition must meet two criteria: knowledge must be of what is, and it must be infallible (152a5–6). As it happens, these two criteria are evidently derived directly from Republic where philosophers are distinguished from their counterfeits by their desire for knowledge, the two criteria for which are: that it be of what is (477a9–b1, b9–10) and that it be infallible (477e6–7). The first criterion sets off the objects of knowledge from the objects of belief which “are and are not at the same time” (478d5–9). The former are clearly identified with Forms, the latter with sensibles. So it seems hardly justified to dismiss the Platonic metaphysical provenance of the two criteria of knowledge in Theaetetus in favor of a supposition that they come from nowhere. If, though, Giannopoulou were to acknowledge, as many readers of Theaetetus would do, that Republic too provides a “subtext” for Theaetetus, it would be even more difficult to sustain the conceit that the latter dialogue was written to reinforce the portrait of Socrates in Apology and not to expose a central idea in Plato’s constructive philosophy.
The core of the book consists of four chapters, one on the introductory conversation and three on the three definitions of knowledge examined in the dialogue. In the first of these Giannopoulou wants to focus on Socrates’ midwifery, in particular with its underlying epistemology. She argues that “we view Socrates’ obstetric infertility as the suppression of beliefs in the sense of definitions, and of theories for and against other people’s definitions and their relevant beliefs” (41). She reasons that Socrates’ barrenness must be the inability even to engender beliefs, much less knowledge or wisdom. Why, though, asks the author, does Socrates in this dialogue lapse into mental infertility? The answer, she argues, is that Socrates realizes that his beliefs are inferior to divine wisdom and cannot lead to knowledge (46). This interpretation presumes, of course, that over against Republic, beliefs could somehow lead to knowledge. Indeed, if Socrates’ beliefs could do so, it is hard to see in what way they are inferior to divine wisdom.
The largest section of the book is devoted to the exchange between Theaetetus and Socrates concerning the definition of knowledge as sense-perception. It is crucial to Giannopoulou’s case not only that Protagorean relativism, viewed as sophistry, be the focus of the criticism of this definition, but that Protagoras continue to be lurking in the background in the examination of the subsequent two definitions. So the definitions of knowledge as true belief and as true belief with logos contain implicit criticisms of Protagoras. Thus is the contrast between Socrates and sophistry supposed to be shown to be central to the dialogue. But this is implausible for a number of reasons, not the least of which is that Protagoras is never mentioned again after the refutation of the first definition. More pointedly, Protagorean relativism (along with Heraclitean flux theory) is introduced explicitly to provide the strongest possible support for the definition of knowledge as sense-perception. When that definition is eliminated, Protagorean theories are no longer relevant, even if it is possible to construct some fanciful connection between the consideration of the possibility of false belief in the second definition and Protagoras’ seemingly self-contradictory denial of this possibility.
The analysis of the refutation of Protagorean relativism is interrupted by a digression on the life of the philosopher (90–101). Giannopoulou argues that Socrates’ midwifery is a form of godlikeness because “Socrates’ position between orator and philosopher is essential to godlikeness as a virtue informed by justice, piety, and his special brand of wisdom” (91). Despite Socrates’ professed ignorance, he is truly wise since he recognizes that god is supremely just and that man is godlike insofar as he has become as just as possible (97). And yet, as a barren midwife, Socrates cannot articulate the essence of justice or piety. Nor can he give an account of wisdom. Socrates is godlike but his limitations prevent him from defining godlikeness (99). So, Socrates “possesses practical knowledge of the virtues, which falls short of theoretical knowledge” (98). This “practical knowledge” of the virtues appears to be like the “illusory virtue” or “popular and political virtue” of Phaedo (69b6, 82a11) and the virtue without wisdom of Republic (619d1). It is indeed odd if Plato is mounting a second defense of the life of Socrates and implicitly describing him as the sort of person who, in Republic Book Ten, chooses for his next life the life of a tyrant, precisely because he does not have genuine wisdom.
The ultimate refutation of Protagoras depends on the argument that there is no knowledge without the attaining of truth, and no such attainment is possible without grasping being, and grasping being, along with other koina, is the task of the mind, not the senses. The meaning of ta koina here is obviously crucial. These are certainly not, as Giannopoulou would have it, “abstract concepts” (119) or, more confusedly, “common terms” which help us to examine abstract concepts (121). They are much more likely intended to stand in contrast with idiai aisthēseis (166c4), which are the unique perceptual and unrepeatable experiences that the relativist claims are the objects of knowledge. That is, ta koina are objects which are commonly available to us and are not uniquely or idiosyncratically accessible. But it is precisely the objectivity of ta koina that makes it disastrously wrong to identify them with any sort of concepts which, as Plato points out in Parmenides, are only “in the soul” and cannot therefore be identified with what explains the samenesses and differences among things or the being that they possess (132b6ff). It seems to me that Giannopoulou’s resolve to eschew metaphysics misleads her into a completely anodyne interpretation of this central passage in the dialogue, missing thereby the reason why sense-perception will no longer play any role in a possible definition of knowledge and, a fortiori, nor will Protagorean relativism.
The last two sections of the book explore the second and third definitions of knowledge as true belief and as true belief plus a logos. For the second definition, Giannopoulou argues that Socrates’ discourse on false belief is an indirect criticism of Protagoras’ belief in the impossibility of false judgment (122). The word “indirect” here is probably intended to blunt the obvious criticism that Protagoras is nowhere mentioned in this part of the dialogue. In fact, the argument is in essence a straightforward modus tollens : if knowledge is true belief, then false belief is not possible; but false belief is possible; therefore, knowledge is not true belief. What we need to question, of course, is the first premise. And if we recur to the two criteria of knowledge laid down at the beginning of the discussion, the answer is plain. If true belief were knowledge, then as such it would be the infallible grasp of that which is. But if this is so, then, there is no thing that is a “false” grasp of that which is. Aristotle makes a similar point in Metaphysics Book Nine, employing the metaphor of “touching.” But this means that since there is no such thing as the infallible grasp of the objects of belief, no belief can ever be massaged into being knowledge, whatever additional factors are added. This is not a happy result for those who want to hold out hope that Plato has come around at the end of the dialogue to at least allowing the possibility of empirical knowledge. At the end of her chapter on true belief, Giannopoulou actually proposes that the refutation of the claim of true belief to be knowledge by means of the example of an eyewitness in relation to a jury that has a true belief about the accused implies that “[o]nly an eyewitness with astonishing powers of observation can meet Socrates’ high standards for knowledge” (153). Mustn’t the eyewitness use his (fallible) sense- perception?
The last definition of knowledge as true belief plus an account is examined in the final chapter before the brief concluding chapter. Although Giannopoulou does not seem to think that the final definition of knowledge is correct, she nevertheless says a number of things that lead one to suppose that she thinks that knowledge is somehow to be found in true belief with some sort of account. I do not follow this at all. She claims that in Socrates’ “dream” he actually endorses the view that both the elements and the complexes of elements in an object can be knowable and that these are “cognitively symmetrical” (165), and that “perceptible elements are knowable when the soul receives the reports of more than one sense and pronounces on their koina ” (165–6). So, elements are knowable and their knowability presupposes the activity of the soul. Even more puzzling is her analysis of the last refutation of the claim that logos in the sense of a distinguishing mark turns true belief into knowledge. She denies that this sense of logos in fact turns true belief into knowledge, although it “buttresses the truth of a judgment” (178). But she concludes that knowledge is shown in this dialogue to be of “abstract entities” (180). These she identifies with Plato’s Forms where the distinguishing mark is an individuating feature of Forms (180). So, “one comes to know the difference of a Form by grasping its essence and then expressing it in a definitional account” (181). In fact, she concludes, Forms are “the sole objects of Platonic knowledge and admit of definitions” (183). This last claim seems to me to be true, although the author’s affirmation of it does seem to sit ill with her rejection of the presence of metaphysics in this dialogue.