In Metaphysics Γ 4-6 Aristotle argues that Protagoras is committed not just to denying the PNC, but also to asserting its contrary. In this paper, I offer an analysis of this commitment. I try to show that Aristotle is working with a specific idea in mind: a Protagoreanism ontologically linked to the flux doctrine, as Plato suggested in Theaetetus 152-160.

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)

With the use of a particular metaphor, which appears at the end of the Cratylus and is taken up with perfect symmetry at the beginning of the Theaetetus, Plato certainly wanted to indicate the succession of Cratylus–Theaetetus as an order for reading the two dialogues, which Trasillus faithfully reproduced in structuring the second tetralogy of Platonic dialogues. The claim of the theory of ideas, with which the Cratylus ends, must therefore be considered the background in which to place not only (...) the analysis of the name carried out in the Cratylus, but also the discussion and criticism of the epistemological theories examined and refuted in the Theaetetus. The transition from the discussion of the name to that of the logos is another important theoretical element that connects the two dialogues. Another one is the theory of knowledge, already precisely elaborated in the Cratylus, and taken up and deepened in the Theaetetus. Finally, the theme of false and error is a third theoretical element common to the two dialogues, which, starting from Euthydemus, finds its solution in the Sophist. (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 article provides a rigorous defense of innate true belief in the Meno, to my knowledge, the first of its kind. While several commentators have proposed innate true belief in the past, the position has never been defended or explained in detail. Instead, the most thorough discussions of Plato’s innatism have opted for different innate objects. I defend my proposal against these recent alternatives by showing that the passages often thought to imply innate knowledge can arguably be better read in (...) other ways. I then argue that they should be so read, because of an “awareness condition” Plato had on knowledge at the time. (shrink)

We examine the discussion about the definition of knowledge as true judgment accompanied by logos in Theaetetus 201c-210c, in order to ascertain which of the recent alternative interpretations is more consistent with the text. To accomplish this, we intend to analyze the text and explore in detail the secondary literature about it.

A puzzle about false judgement is raised in the Theaetetus (187d-200c), but not successfully answered there. On the proposed account, the confusion that explicitly vitiates Theaetetus’ final attempt to define knowledge is already at work implicitly in this puzzle. Theaetetus shares popular assumptions about knowledge (epistēmē), but also accepts that there are cognitive constraints on judgement (doxa): the puzzle arises because he fails to distinguish the one cognitive condition from the other.

In this paper, I examine several key issues relating to the definition of knowledge as perception in the first part of Plato's Theaetetus. I begin by explaining the workings of the ‘secret doctrine’ of perception, which is introduced in order to support the idea that perception is incorrigible, and then turn to examine the two refutations of the definition of knowledge as perception which appear at the end of the first part of the Theaetetus. I shall present and explain distinct (...) lines of interpretation pertaining to these passages and explore the consequences they attempt to draw regarding Plato's views on the perceptual world, the nature of perception and how these bear on his conception of knowledge. (shrink)

In this second installment on the Theaetetus, I discuss Theaetetus' second and third definitions of knowledge, namely, ‘true judgment’ and then ‘true judgment with the addition of an account’. I offer a brief description of Socrates' intricate examination of these suggestions, concentrating especially on the discussion of false judgment and that of the so-called ‘Dream Theory’. I then proceed to map different lines of interpretation for these passages that have been offered by scholars writing in the last 40 years.

Hermann Lotze argued that the fact that consciousness simultaneously “holds objects together as well as apart” such that they can be compared implies (a) that there is a simple thinker and (b) that consciousness is an ‘indivisible unity.’ I offer a reconstruction and evaluation of Lotze’s Argument from Comparison. I contend that it does not deliver (a) but makes a good case for (b). I will relate Lotze’s argument to the contemporary debate between “top-down” and “bottom-up” views of the unity (...) of consciousness and locate it in its historical context. (Kant and Herbart figure prominently here.). (shrink)

Two readings of the much-discussed περιτροπή argument of "Theaetetus" 170c-171c have dominated the literature. One I call "the relativity reading". On this reading, the argument fails by ignoratio elenchi because it "carelessly" omits "the qualifications 'true for so-and-so' which [Protagoras'] theory insists on" (Bostock 1988: 90). The other reading I call "the many-worlds interpretation". On this view, Plato's argument succeeds in showing that "Protagoras' position becomes utterly self-contradictory" because "he claims that everyone lives in his own relativistic world, yet at (...) the same time he is forced by that very claim to admit that no one does" (Burnyeat 1976b: 48). I discuss and criticise both readings, and present a third, according to which the point of the argument is, very roughly, that Protagoras is committed to equating truth and truth-for, and so, further, to their intersubstitutability. This further commitment proves fatal to his argument. (shrink)

The strange and challenging stretch of dialectic with which Plato’s Sophist begins and ends has confused and frustrated readers for generations, and despite receiving a fair amount of attention, there is no consensus regarding even basic issues concerning this method. Here I offer a new account of bifurcatory division as neither joke nor naïve method, but instead a valuable, propaedeutic method that Plato offers to us readers as a means of embarking upon the kind of mental gymnastics that will stretch (...) us properly in preparation for further, more challenging dialectical work. Considering several interpretive issues, I argue that bifurcatory division is a process of collective inquiry into the common through which an account, both definitional and taxonomical, is discovered. Depending on the level of understanding exhibited by the inquirers, this account may or may not allow for noetic understanding of the object in the deepest sense. (shrink)

This article seeks to answer why there are two different versions of Meno’s Paradox. I argue that the dilemma contained in Socrates’s version is a pre-existing puzzle, familiar to both Meno and Socrates before their discussion. The two versions of the paradox are thus different because Meno’s version is a mistaken attempt to remember the puzzle contained in Socrates’s version. Although Meno’s version is a mistaken attempt to state Socrates’s version, it is a philosophically richer puzzle that makes three interesting (...) points about inquiry and recognition. After arguing that Socrates’s version is unsound and that Meno’s version is an attempt to recollect or remember it, I analyze Meno’s version in detail. In closing, I consider the relationship between the notion of recognition, which figures prominently in Meno’s version, and the theory of recollection, suggesting that the latter may have arisen as an attempt to explain the origin of moral intuitions. (shrink)

Stoics and Sceptics distinguish belief (doxa) from a representationally and functionally similar but sub-doxastic state: passive yielding to appearance. Belief requires active assent to appearances, that is, affirmation of the appearances as true. I trace the roots of this view to Plato's accounts of doxa in the Republic and Theaetetus. In the Republic, eikasia and pistis (imaging and conviction) are distinguished by their objects, appearances versus ordinary objects; in the Theaetetus, perception and doxa are distinguished by their objects, proper perceptibles (...) versus ‘commons’, including being. But underlying these ontological distinctions is a psychological one: the lower mental states are confined to their lower objects because they are passive; the higher mental states have access to higher objects because they result from questioning appearances and making active affirmations about how things are. This doctrine of doxa anticipates both the Hellenistic one and modern accounts of belief as ‘aiming at truth’; it also shows Plato's views of doxa to have more in their favour philosophically and to cohere better with one another than generally thought. (shrink)

The version of the paradox of false judgement examined at Tht. 188c10–189b9 relies on the assumption that to judge falsehoods is to judge the things which are not. The presentation of the argument displays several syntactic ambiguities: at several points it allows the reader to adopt different syntactic connections between the components of sentences. For instance, when Socrates says that in a false judgement the cognizer is “he who judges the things which are not about anything whatsoever” (188d3–4), how should (...) the clause “about anything whatsoever” be construed? In common with “he who judges” and “the things which are not” (in which case the cognizer would be “he who judges about anything whatsoever the things which are not about it”), or exclusively with “he who judges” (in which case the cognizer would be “he who judges about anything whatsoever the things which are not”)? The most plausible answer is that both construals are envisaged. Accordingly, the argument has two branches corresponding to these two alternative construals. In particular, it attempts to show that in both cases the cognizer will address what does not exist – an impossibility. The idea that a false judgement is concerned with what is not about its reference has a clear echo in the Sophist. The way in which the problem is handled in the Theaetetus provides a hint that can help to find a solution for the hotly debated issue of the interpretation of the Sophist’s account of false statement. (shrink)

Two readings of the much-discussed περιτροπή argument of "Theaetetus" 170c-171c have dominated the literature. One I call "the relativity reading". On this reading, the argument fails by ignoratio elenchi because it "carelessly" omits "the qualifications 'true for so-and-so' which [Protagoras'] theory insists on" (Bostock 1988: 90). The other reading I call "the many-worlds interpretation". On this view, Plato's argument succeeds in showing that "Protagoras' position becomes utterly self-contradictory" because "he claims that everyone lives in his own relativistic world, yet at (...) the same time he is forced by that very claim to admit that no one does" (Burnyeat 1976b: 48). I discuss and criticise both readings, and present a third, according to which the point of the argument is, very roughly, that Protagoras is committed to equating truth and truth-for, and so, further, to their intersubstitutability. This further commitment proves fatal to his argument. (shrink)

This paper considers the use that Plato makes of the Principle of Non-Contradiction in his engagements with eristic refutations. By examining Plato’s use of the principle in his most detailed engagements with eristic—in the Sophist, the discussion of “agonistic” argumentation in the Theaetetus, and especially the Euthydemus—I aim to show that the pressure exerted on Plato by eristic refutations played a crucial role in his development of the PNC, and that the principle provided him with a much more sophisticated means (...) of demarcating philosophical argumentation from eristic than he is generally thought to have. In particular, I argue that Plato’s qualified formulation of the PNC restricts the class of genuine contradictions in such a way that reveals the contradictions that eristics produce through their refutations to be merely apparent and that Plato consistently appeals to his qualified conception of genuine contradiction in his encounters with eristics in order to demonstrate that their refutations are merely apparent. The paper concludes by suggesting that the conception of genuine contradiction afforded by the PNC did not just provide Plato with a way of demarcating genuine from eristic refutations, but also with an answer to substantive philosophical challenges that eristics raised through their refutations. (shrink)