'What exactly is knowledge?' The Theaetetus is a seminal text in the philosophy of knowledge, and is acknowledged as one of Plato's finest works. Cast as a conversation between Socrates and a clever but modest student, Theaetetus, it explores one of the key issues in philosophy: what is knowledge? Though no definite answer is reached, the discussion is penetrating and wide-ranging, covering the claims of perception to be knowledge, the theory that all is in motion, and the perennially (...) tempting idea that knowledge and truth are relative to different individuals or states. The inquirers go on to explore the connection between knowledge and true judgement, and the famous threefold definition of knowledge as justified true belief. Packed with subtle arguments, the dialogue is also a work of literary genius, with an unforgettable portrait of Socrates as a midwife of wisdom. This new edition uses the acclaimed translation by John McDowell. It includes a valuable introduction that locates the work in Plato's oeuvre, and explains some of the competing interpretations of its overall meaning. The notes elucidate Plato's arguments and draw connections within the work and with other philosophical discussions. ABOUT THE SERIES: For over 100 years Oxford World's Classics has made available the widest range of literature from around the globe. Each affordable volume reflects Oxford's commitment to scholarship, providing the most accurate text plus a wealth of other valuable features, including expert introductions by leading authorities, helpful notes to clarify the text, up-to-date bibliographies for further study, and much more. (shrink)

I argue that Plato's purpose in the discussion of false belief in the "Theaetetus" is to entertain and then to reject the idea that thinking is a kind of mental grasping. The interpretation allows us to make good sense of Plato's discussion of 'other-judging' (189c-190e), of his remarks about mathematical error (195d-196c), and most importantly, of the initial statement of the puzzle about falsity (188a-c). That puzzle shows that if we insist on conceiving of the relation between thought and (...) its objects on the model of holding or grasping something in our hands, we will be unable to account for the possibility of false identity judgments: For no one who is literally grasping two things in his hands would seriously entertain the idea that one of the things is numerically identical with the other. (shrink)

I argue that Plato's purpose in the discussion of false belief in the "Theaetetus" is to entertain and then to reject the idea that thinking is a kind of mental grasping. The interpretation allows us to make good sense of Plato's discussion of 'other-judging' (189c-190e), of his remarks about mathematical error (195d-196c), and most importantly, of the initial statement of the puzzle about falsity (188a-c). That puzzle shows that if we insist on conceiving of the relation between thought and (...) its objects on the model of holding or grasping something in our hands, we will be unable to account for the possibility of false identity judgments: For no one who is literally grasping two things in his hands would seriously entertain the idea that one of the things is numerically identical with the other. (shrink)

M. J. Levett's elegant translation of Plato's _Theaetetus_, first published in 1928, is here revised by Myles Burnyeat to reflect contemporary standards of accuracy while retaining the style, imagery, and idiomatic speech for which the Levett translation is unparalleled. Bernard William’s concise introduction, aimed at undergraduate students, illuminates the powerful argument of this complex dialogue, and illustrates its connections to contemporary metaphysical and epistemological concerns.

Plato's Theaetetus and Sophist are two of his most important dialogues, and are widely read and discussed by philosophers for what they reveal about his epistemology and particularly his accounts of belief and knowledge. Although they form part of a single Platonic project, these dialogues are not usually presented as a pair, as they are in Christopher Rowe's new and lively translation. Offering a high standard of accuracy and readability, the translation reveals the continuity between these dialogues and others (...) in the Platonic corpus, especially the Republic. The supporting introduction and notes help the reader to follow the arguments as they develop, explaining their structure, context and interpretation. This new edition challenges current scholarly approaches to Plato's work and will pave the way for fresh interpretations both of Theaetetus and Sophist and of Plato's writings in general. (shrink)

David Sedley, Lesley Brown; Plato Theaetetus 145–147, Proceedings of the Aristotelian Society, Volume 94, Issue 1, 1 June 1994, Pages 229–242, https://doi.org/1.

After some years (or millennia) most works would no longer be considered eligible for "review." But an exception is called for, if the thrust of an older work is closely paralleled in a much more modern piece, as is the case between Plato's Theaetetus and Richard Rorty's acclaimed, and more recent volume, Philosophy and the Mirror of Nature. To fully understand and appreciate Rorty 's contribution to the subjects he raises, one must study his book in conjunction with Plato's (...) Theaetetus-where very similar issues have been discussed before. Both works concern a central question for philosophy: "What is knowledge?" The discussants in Plato's dialogue the Theaetetus, never do succeed in finding a satisfactory definition for knowledge, yet they at least realize to avoid thinking they know about the subject when, in fact, they lack that knowledge. Since Rorty explores some new (and not so new) ideas on these topics, Plato's discussants ask him a few questions. (Reprinted from original in Antioch Review). (shrink)

ON ITS surface the Theaetetus ends inconclusively. It has even been said to end in failure. Yet this dialogue is exceptionally full of promise. The speakers are singularly well disposed. Two of them are gifted and resemble one another in looks and interests. Inquiry progresses splendidly through most of a long conversation. Although Theaetetus's first two definitions have to be given up, he is in the process led through a meticulous survey of cognition. These and other circumstances are (...) too auspicious for the termination of the dialogue to be taken at face value. The present essay is meant to disclose a partly hidden successful ending. The latter has to be discovered by readers. However the dialogue itself licenses and encourages active interpretation. The last ten pages of discourse contain so many specific clues that the text can be read as a single development ending in an affirmative conclusion. There is indeed a way to construe "true opinion with logos" so it applies to a cognition worthy of the name "epistémé.". (shrink)

The Theaetetus is a remarkably rich dialogue that raises any number of important epistemological questions, and it rewards careful study. By systematically and thoroughly examining the text and by exploring the issues Plato raises in terms of modern epistemic concerns, Platos Theaetetus adds anew and helpful perspective to the ever growing body of scholarship on this pivotal dialogue.-Ancient Philosophy.

This famous passage has given rise to much discussion and some perplexity. Theodoras the mathematician is represented by Theaetetus as proving the irrationality of the square roots of the numbers from 3 to 17: ‘He took the separate cases up to the root of 17 square feet; and there, for some reason, he stopped.’ The passage is of great importance in the history of Greek mathematics for more than one reason. Theaetetus is said to have generalized the proof (...) of the irrationality of square roots of non-square integers; and thus his connexion with this passage is important because Plato here obviously implies that Theodorus was not giving a generalized proof—otherwise, why should he go up to 17 ? If Theodorus did not know the generalized proof, he clearly had to proceed by enumeration and proof of particular case. (shrink)

This famous passage has given rise to much discussion and some perplexity. Theodoras the mathematician is represented by Theaetetus as proving the irrationality of the square roots of the numbers from 3 to 17: ‘He took the separate cases up to the root of 17 square feet; and there, for some reason, he stopped.’ The passage is of great importance in the history of Greek mathematics for more than one reason. Theaetetus is said to have generalized the proof (...) of the irrationality of square roots of non-square integers; and thus his connexion with this passage is important because Plato here obviously implies that Theodorus was not giving a generalized proof—otherwise, why should he go up to 17? If Theodorus did not know the generalized proof, he clearly had to proceed by enumeration and proof of particular case. (shrink)

'What exactly is knowledge?' The Theaetetus is a seminal text in the philosophy of knowledge, and is acknowledged as one of Plato's finest works. Cast as a conversation between Socrates and a clever but modest student, Theaetetus, it explores one of the key issues in philosophy: what is knowledge? Though no definite answer is reached, the discussion is penetrating and wide-ranging, covering the claims of perception to be knowledge, the theory that all is in motion, and the perennially (...) tempting idea that knowledge and truth are relative to different individuals or states. The inquirers go on to explore the connection between knowledge and true judgement, and the famous threefold definition of knowledge as justified true belief. Packed with subtle arguments, the dialogue is also a work of literary genius, with an unforgettable portrait of Socrates as a midwife of wisdom. This new edition uses the acclaimed translation by John McDowell. It includes a valuable introduction that locates the work in Plato's oeuvre, and explains some of the competing interpretations of its overall meaning. The notes elucidate Plato's arguments and draw connections within the work and with other philosophical discussions. ABOUT THE SERIES: For over 100 years Oxford World's Classics has made available the widest range of literature from around the globe. Each affordable volume reflects Oxford's commitment to scholarship, providing the most accurate text plus a wealth of other valuable features, including expert introductions by leading authorities, helpful notes to clarify the text, up-to-date bibliographies for further study, and much more. (shrink)

In the Theaetetus, Plato looks afresh at a problem to which, he now realizes, he had earlier given an inadequate answer: the problem of the nature of knowledge. What Plato has to say on this question is of great interest and importance, not only to scholars of Plato, but also to philosophers with wholly contemporary interests. This book is a sustained philosophical analysis and critique of the Theaetetus. David Bostock provides a detailed examination of Plato's arguments and the (...) issues that they raise. He adjudicates on rival interpretations of the text, and looks at the relations between this and other works of Plato. The book does not presuppose any knowledge of Greek. (shrink)

This paper is a test case for the claim, made famous by Myles Burnyeat, that the ancient Greeks did not recognize subjective truth or knowledge. After a brief discussion of the issue in Sextus Empiricus, I then turn to Plato's discussion of Protagorean views in the Theaetetus. In at least two passages, it seems that Plato attributes to Protagoras the view that our subjective experiences constitute truth and knowledge, without reference to any outside world of objects. I argue that (...) these passages have been misunderstood and that on the correct reading, they do not say anything about subjective knowledge. I then try out what I take to be the correct reading of the passages. The paper concludes with a brief discussion of the importance of causes in Greek epistemology. (shrink)

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Timothy Chappell’s new translation of the Theaetetus is presented here in short sections of text, each preceded by a summary of the argument and followed by his philosophical commentary on it. Introductory remarks discuss Plato and his works, his use of dialogue, the structure of the Theaetetus, and alternative interpretations of the work as a whole. A glossary and bibliography are provided.

Theaetetus, asked what knowledge is, replies that geometry and the other mathematical disciplines are knowledge, and so are crafts like cobbling. Socrates points out that it does not help him to be told how many kinds of knowledge there are when his problem is to know what knowledge itself is, what it means to call geometry or a craft knowledge in the first place—he insists on the generality of his question in the way he often does when his interlocutor, (...) asked for a definition, cites instead cases of the concept to be defined. (shrink)

David Sedley, Lesley Brown; Plato Theaetetus 145–147, Proceedings of the Aristotelian Society, Volume 94, Issue 1, 1 June 1994, Pages 229–242, https://doi.org/1.

In this paper I discuss the dialogues between 'Protagoras', Theodorus and Socrates in "Theaetetus" 161-171 and emphasise the importance for this passage of a dilemma which refutation is shown to pose for relativism at 161e-162a. I argue that the two speeches delivered on Protagoras' behalf contain material that is deeply Socratic and suggest that this feature of the speeches should be interpreted as part of Plato's philosophical case against relativism, reflecting the relativist's own inability to defend his theory from (...) attempts to refute it. I then discuss Theodorus' role in the refutation of Protagoras and argue that his voice is needed to get relativism disproved in the self-refutation argument of 171a-c. I conclude with a brief discussion of the image of Protagoras at 171d. (shrink)

This book is a sustained philosophical analysis and critique of Plato's Theaetetus. Presupposing no knowledge of Greek, Bostock provides a detailed examination of Plato's arguments and the issues they raise, rival interpretations of the text, and the relations between the Theaetetus and Plato's other works.

This is an English translation of Plato's dialogue concerning the nature of knowledge. In this dialogue, Socrates and Theaetetus discuss three definitions of knowledge: knowledge as nothing but perception, as true judgment and as true judgment with an account. Focus Philosophical Library translations are close to and are non-interpretative of the original text, with the notes and a glossary intending to provide the reader with some sense of the terms and the concepts as they were understood by Plato’s immediate (...) audience. (shrink)

M. J. Levett's elegant translation of Plato's _Theaetetus_, first published in 1928, is here revised by Myles Burnyeat to reflect contemporary standards of accuracy while retaining the style, imagery, and idiomatic speech for which the Levett translation is unparalleled. Bernard William’s concise introduction, aimed at undergraduate students, illuminates the powerful argument of this complex dialogue, and illustrates its connections to contemporary metaphysical and epistemological concerns.

Originally published in 1990. This book discusses in a philosophically responsible and illuminating way the progress of the dialogue and its separate sections to improve our understanding of Plato’s work on Theaetetus. An early coverage of this dialogue, this investigation predated a surge in study of Plato’s piece which examined Socratic and pre-Socratic thought. The author’s argument is that the _Theaetetus_ engages in re-evaluation of earlier doctrines of middle-period Platonism as well as reaffirming theories about knowledge. An important work (...) in Platonic studies and epistemology. (shrink)

Any comprehensive interpretation of the "Theaetetus" has to provide answers to, among others, two very general questions concerning that dialogue: "What is Plato's relation to the problems faced in the "Theaetetus"?" and "What is the significance of the absence of the Forms from the discussion of the "Theaetetus", given their undoubted relevance to the topic of the dialogue, i.e. knowledge?" Predominantly, the answer given to the first question in the literature has been that the problems are those (...) that Plato is trying to tackle and the one to the second question, when it has been addressed at all, that the Forms are left out of the discussion because Plato no longer thought them relevant, either for having abandoned or seriously revised them, by the time of writing the "Theaetetus". In this study of the Wax Block and the Aviary models of judgment that occur in the second part of the "Theaetetus" as part of its discussion of the problem of false judgment, I argue that the problems faced there actually arise because of the neglect of Forms. The discussion of the second part is, I contend, carried out on a materialist ontology, an ontology assumed because it suits the definition of knowledge as true judgment which inaugurates that part of the dialogue, an ontology in no way subscribed to by Plato. The Wax Block is, I explain, a materialist model and fails in the case of judgments about numbers for treating them on a par with material subjects, ignoring their intelligible status. In particular, it fails to distinguish judging 5 and 7 to be 11 from judging 12 to be 11 because of its neglect of Forms; Plato would distinguish those judgments by distinguishing 5 and 7 from 12 with help from his part-whole analysis, to which the Forms are essential. (shrink)

This dissertation is a study of Plato's Theaetetus . I argue that the Theaetetus is fundamentally an extended reductio of a radical materialist view---the view that the only things that there are perceptible, material particulars with no properties or relations. Based on evidence from the Sophist---the sequel dialogue to the Theaetetus---I show that, according to Plato, this radical materialism results from ignoring the intelligible Forms and the participation of things in them. The radical materialist ontology also implies (...) a certain view of judgments and statements, essentially the view that judging or stating is naming or identifying the thing that is judged or stated. ;I read the discussion of the thesis that knowledge is true judgment in the second part of the Theaetetus as, first illustrating difficulties that the radical materialist view gives rise to in explaining the possibility of false judgment, but then indicating how false judgment can occur on that view, only to show that the radical materialist cannot give an account of simple arithmetical mistakes on his assumptions. ;The third part of Theaetetus, dealing with the thesis that knowledge is true judgment with an account, concentrates on the implications of radical materialism for the unity and complexity of objects; the radical materialist cannot give an account of how there can be a whole with parts. He also cannot explain the possibility of systematic knowledge and expertise in a field, such as arithmetic or grammar, because of his commitment to the particularity of what there is, and therefore, of what is known. (shrink)