Plato's Theaetetus

The Theaetetus' final definition of knowledge as true belief with a logos (201c-210b) ends in merely apparent failure. The three accounts of logos individually fail. Yet Plato intends us to see that together they constitute a structured whole of functional parts, the necessary and sufficient conditions for a proper logos. Material from the Statesman, the Theaetetus' dramatic sequel, provides crucial support to the Theaetetus' own evidence for this.

Socrates’ midwife metaphor in Theaetetus depends logically on the
concept of male spiritual pregnancy. Male spiritual pregnancy is typically
understood as a process in which a young man develops in his mind a theory
or idea; a spiritual child is, on this view, a theory; and spiritual childbirth is
the painful movement of a developed theory from the mind into the speechworld.

Although this account of spiritual pregnancy and maieutics is widely
accepted in the scholarship, it cannot be upheld. The intelligibility of Socrates’
midwife metaphor requires the recognition of two different kinds of pregnancy,
the false and the true. The first and false kind is roughly as the standard interpretation
says that it is: a theory germinating in the mind; but Theaetetus’s true
spiritual child is not a theory of knowledge—it is wisdom in his soul; true spiritual
pregnancy is the actualisation of the soul’s potential for wisdom.

This paper aims at showing the many ways in which the self-referential dimension is present – by being both dramatically shown and argumentatively thematized – in Plato’s Theaetetus. A general reading of the whole dialogue is provided and argued for, which individuates self-referentiality as its very speculative keystone: the Theaetetus exhibits an attempt to attain knowledge of knowledge where the soul comes to cognize the soul itself (its own cognitive powers), through producing opinions about opinions, appearances about appearances, even dreams about dreams; the characters discuss about discussing, get things wrong about getting things wrong, make digressions about making digressions where the philosopher characterizes the philosopher, they search for a logos of “logos”, and so on. Such a widespread self-referential dimension shows its speculative value as it is combined with a both a progressive and retroactive way of proceeding: each stage of the research – by way of an immanent criticism – brings about the next one and shows
its very meaning only retrospectively, from the point of view of the next stage, and each new stage both overcomes but also “preserves” the previous one, so that the aporetic end of the dialogue is only apparent and needs to be taken as an incompleteness rather than as a failure.

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 Cra-tylus, 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.

Publisher's blurb:  _The People of Plato_ is the first study since 1823 devoted exclusively to the identification of, and relationships among, the individuals represented in the complete Platonic corpus.  It provides details of their lives, and it enables one to consider the persons of Plato's works, and those of other Socratics, within a nexus of important political, social, and familial relationships. Debra Nails makes a broad spectrum of scholarship accessible to the non-specialist.  She distinguishes what can be stated confidently from what remains controversial and—with full references to ancient and contemporary sources—advances our knowledge of the men and women of the Socratic milieu.  Bringing the results of modern epigraphical and papyrological research to bear on long-standing questions, _The People of Plato_ is a fascinating resource and valuable research tool for the field of ancient Greek philosophy and for literary, political, and historical studies more generally.  In discrete sections, Nails discusses systems of Athenian affiliation, significant historical episodes that link lives and careers of the late fifth century, and their implications for the dramatic dates of the dialogues.  The volume includes a rich array of maps, stemmata, and diagrams, plus a glossary, chronology, plan of the agora in 399 B.C.E., bibliography, and indices.

This paper examines the prologue of Plato's Sophist in light of interpretive claims by Proclus, and revived by Myles Burnyeat, that Plato imaged in the opening scene of his dialogues the main philosophical themes of the work. This paper applies that insight to the prologue of the Sophist and argues that Proclus is right but that the work in which this prologue is embedded is much larger than the dialogue it introduces. A close reading of the Sophist's prologue reveals it to image, in a literary way, the whole series of dialogues—Theaetetus, Sophist, Statesman, and missing Philosopher—of which the Sophist is a member. At the end of the Sophist, the sophist is identified as imitator of the wise man. The paper explores the sophist in relation to the kinds it imitates, including two sorts of wise men, the philosopher and the statesman, and asks whether there is a wide kind covering all of them, both genuine experts and their benign and dangerous imitators. If there is such a kind, what is its status as a kind? The paper considers a genealogical family, descended from a common ancestor

Scholars have typically viewed book 3 of Aristotle’s "Metaphysics" as an unsystematic array of different metaphysical problems. In this article, the author argues that Aristotle organizes them with great care. The principle behind his ordering of the problems stems from Aristotle’s concern with impressing upon his audience the difficulty of becoming thoroughly perplexed. This principle is found to make sense of the discrepancies between Aristotle’s list of the problems in 3.1 and his discussion of them in 3.2–6. In short, Aristotle’s primary concern in Metaphysics 3 is to temper the ambitions of his audience of enterprising physicists, a concern that takes him from the aim of metaphysics to the tension between theology and philosophy. Borrowed as this concern is from the Platonic Socrates, the author shows that the arc of "Metaphysics" 3 is Socratic, and how it is Socratic.

I. GREEK PHILOSOPHY AS A REFORM AND THERAPY OF THE ORDINARY LANGUAGE;
II. HERACLITUS’ EXPERIMENTS WITH LANGUAGE, GRAMMAR AND STYLE
The first part of this investigation draws attention to one understudied, and yet philosophically important approach to language in Greek philosophy from archaic times to Aristotle: the reform of ordinary language, word-making and attempts to discover or to create an ideal language or a language “conforming to nature”. The following cases at point are discussed: the critique of the ordinary language as a product of doxastic imagination in Heraclitus and Parmenides associated with linguistic idealism and the theory of “linguistic error” of mortals in ancient times that resulted in the origin of polytheism and belief in the reality of the phenomenal world of many things misnamed by empty words. The elimination of the words for “birth and death”, “generation and de- struction” as “deceptive” and their systematic replacement by new “correct” mechanistic terminology of “excretion from mixture, recombination and dissolution” of material particles in Ionian physics (Anaximander, Anaxagoras) and Empedocles. The theory of the “disease of language” as the root of mythology and anthropomorphic polytheism of poets in Sophists (Prodicus, the Derveni papyrus), Aristotle’s attempts to give names to “anonymous” moral qualities in Nicomachean Ethics. The idea of a “divine language” is to some extent anticipated in the Homeric topos of the “language of gods” which has Indo-European roots. A suggestion is made en passant that if the author of the “dream theory” in Plato's Theaetetus, quoted by Wittgenstein in Philosophical investigations, I.46 as an ancient antecedent of his simple “objects” in the Tractatus, is Heraclitus rather than Antisthenes (as we argue on the ground of the new reconstruction of grammatical analogy in Heraclitus’ logos-fragments), then a historical link can be established between Wittgenstein's linguistic idealism and Heraclitus’ analogies of “cosmic grammar” and “alphabet of nature”, although in Wittgenstein’s perception it was, of course, a theory of “Socrates” and Plato, not of Heraclitus. Part II is a case at point study of language and style in Heraclitus including following topics: oracular features, syntactic polysemy (hyperbaton), omission of the conjunction καί between opposites, omission of the verb ‘to be’ in the desсriptions of phenomenal change, omission of article with words referring to ‘appearances’ (τὰ φανερά, τὰ δοκέοντα), replacing a standard singularis (ποταμός) with pluralis (ποταμοί), because what we see is a series of rivers
changing every moment, Fränkel’s “proportion” as a means of approaching the unknown, forms of chiasmus, chiastic (amoebean) structure of fragments as a mimesis of the natural cyclical processes (the ‘road up and down’).
Keywords: ancient philosophy, theories of language, origin of religion and mythology, Heraclitus, Parmenides, Anaximander, Anaxagoras, Empedocles, Democritus, Greek sophists, Prodicus, Plato, Aristotle, the Derveni papyrus.

This paper considers the unity of Socrates' twin apparitions of sophist and statesman, alluded to in the Sophist. Examining how these apparitions are at work in the Theaetetus, I argue that the difficulty is that of combining the nurturing or educative role of the statesman with the sophist's practice of refutation. Beginning from Socrates' shift in appearance early in the dialogue, I argue that the cause of this shift is Theaetetus' character, that this forces the general problem Socrates has in mind into a particular form, and that Theaetetus never fully grasps this fundamental, intractable problem. Consequently, the problem's intractability shows why Socratic education is always refutative, and so combines the statesman and sophist's respective arts. And because Theaetetus is the cause of Socrates' shift, the philosopher's appearance is always an ironic reflection of his interlocutor's opinions: the dialogue the Philosopher would have to be named the Theaetetus.

Сажетак: Полазећи од општег историјско-филозофског и културолошког оквира, настојаћемо да реконструишемо смисао и значај Платонове чувене Deus mensura максиме као и њене разноврсне импликације. Темељни став о Богу као мери свих ствари блиско је повезан са Платоновим императивом о човековом " наликовању Богу (ὁμοίωσις θεῷ) ". Одређивање Бога као " мерила " свега што јесте произилази из Платоновог дубоког увида да постоји нешто више од нас, што је нерелативно и апсолутно, а чиме се једино и могу праведно уредити односи међу људима. То представља платонистички одговор на Протагорину дивинизацију човека, и постављање њега као парадигме и мерила свега што јесте. Платонов одговор, међутим, не представља повратак древној мито-поjетској традицији Хомера и Хесиода, већ се састоји у новом разумевању Бого-човечанских односа. Кључне речи: Deus mensura, Платон, наликовање Богу, Протагора Платонова филозофија није само нераскидиво повезана са теологијом, 3 већ је, усудићемо се рећи, упечатљив пример зашто истинска филозофија мора да садржи рефлексије о Богу. Познато је да мисао о највишем бићу прожима целокупну Платонову филозофију: у њеној космологији Бог као управљачки, само-покрећући и непроменљив принцип свега јесте оно на чему почива рационалност и закономерност космоса, као и униформно кретање небеских тела у њему (Тимај, Државник, Закони).

In this Fourth Part of the book, we turn to the Theaetetus, Plato's famous and fertile treatment of the question "what is knowledge?". I shall devote three chapters to this dialogue. My main purpose in this part of the book is to show that Plato is still offering the same answer as before—or similar answers—to the questions about (i) whether one can or should be able to give a definition of what one knows; (ii) what episteme is of (that it is the science that grasps the “what it is” kind of ousia); and (iii) what kind of cognition is supplied by doxa and sense-perception. He also illustrates the inability of geometry and natural science to recognise the inadequacy of their models of science.

This paper offers a detailed reconstruction of the so-called Self-Refutation Argument against Protagoras' "Measure Doctrine" (MD) for which "every appearance is true" (Theaet. 169e8-171c7): the relevant textual and theoretical issues are critically considered such as: whether the argument is meant to refute an "infallibilist" MD (every appearance is true simpliciter) or a relativist MD (every appearance is true for the subject who has it); whether the argument is meant to refute a "qualified" relativism (MD is true) or a global relativism (MD itself is true for those who believe it); whether the argument is generally successful or not, and how its logical, dialectical, rhetorical and phenomenological dimensions are deeply interwoven; which relations connect MD with the epistemological doctrine that knowledge is perception and with the ontological doctrine that "everything is becoming"; how the "broadening" of MD into the thesis that "all beliefs are true" is crucial for the success of the argument; how the many steps of the argument are inferentially related. Theaetetus's first 'baby' is the idea that knowledge is perception (= KP). 1 Socrates congratulates him and suggests that Protagoras said the very same thing but in a different way, as he literally wrote that «man is the measure of all things (of those which are, that they are, of those which are not, that they are not)» 2 , by which he meant roughly that «any given thing is for me the way it appears to me, and for you the way it appears to you» (151e8-152a8) (Measure Doctrine = MD); 3 for example, the same gust of wind will appear (and so be) cold to me and appear (and so be) hot to you (b2-7). Such an assimilation between KP and MD is not an identity, but a strong theoretical connection: it is grounded first on the equivalence between a subject S perceiving something a certain way and something appearing to S a certain way (S's αἴσθησις of F = F's φαίνεσθαι to S); 4 through this equivalence, MD becomes "X is to S the way S perceives it", so perception is always «of what is» and is never false/mistaken, 5 just as knowledge is supposed to be, and indeed as KP makes explicit. Then the Secret Doctrine (= SD) comes into the picture: whilst MD was what the letter of Protagoras's homo-mensura sentence in his Truth purportedly meant in spirit, SD was "secret", so-net of irony or dramatic purpose-it is a doctrine that Socrates suggests Protagoras could have shared or assumed but which he did not share apertis verbis or even "mean", as in a climax from a literal to a more 1 151e1-3: though cautiously proposed (δοκεῖ οὖν μοι… ὥς γε νυνὶ φαίνεται), KP is meant to be a proper definition (οὐκ ἄλλο τί ἐστιν ἐπιστήμη ἢ αἴσθησις)-the smart Theaetetus has been methodologically "trained" by Socrates beforehand about the inadequateness of providing examples or incomplete characterizations-so definiens and definiendum are supposed to be co-extensive: if KP is true, any case of knowledge is a case of perception and the other way round. 2 152a2-4. 3 I take λέγει at 152a6 as meaning "means" rather than "says", as it is an explicitly Socratic interpretation of what Protagoras wrote. 4 Just below (152c1-3) the equivalence between αἴσθησις and φαντασία is explicitly stated, but it is also limited to cases of stricto sensu sensory perception (i.e. of properties like [cold], [warm] and the like). 5 One comes to be perceiving, you come to be perceiving something (160a9-10), perception cannot be objectless.

This thesis is concerned with Theaetetus' definition of knowledge (‘Knowledge is perception') and Protagoras' Measure Doctrine (‘Man is the measure of all things') as discussed in Plato's Theaetetus (151e-187a). I shall argue that Protagoras' Measure Doctrine is best understood as a doctrine of infallibilism: all beliefs are true. I shall argue that Theaetetus' definition commits Theaetetus to perceptual infallibilism: all perceptual beliefs are true. Further, I shall argue that Protagoras' Secret Doctrine (152d-160c) underpins perceptual infallibilism by means of a process ontology: perceptual properties are processes involving objects and perceivers. I shall argue that this process ontology explains three key components of the Secret Doctrine: the Relationalist Thesis (‘Nothing is one thing just by itself'), the Flux Thesis (‘Nothing ever is, but things are always becoming') and the linguistic reforms (the rejection of ‘to be' in favour of ‘to become'). I shall provide a detailed analysis and criticism of the relativist interpretation, according to which the Measure Doctrine amounts to relativism about truth: each belief is true (not simpliciter, but) in relation to the believer. In particular, I shall argue that the refutation of the Measure Doctrine (170c-171c) targets infallibilism rather than relativism about truth. I shall argue that the refutation of the Radical Flux doctrine (‘Everything is always changing with every kind of change in every respect'; 179d-183c) hinges on the view that Radical Flux precludes universals from being instantiated. This view explains both the incompatibility between Radical Flux and Theaetetus' definition and the incoherence of Radical Flux. Further, I shall argue that neither Theaetetus nor Protagoras is committed to Radical Flux: the refutation targets proponents of Theaetetus' definition and of the Secret Doctrine who also endorse Radical Flux. Finally, I shall argue that the refutation of Theaetetus' definition (at 184b-187a) hinges on the view that perceiving does not—and knowing does—involve making true judgements.

with approval by such an audience requires that one (also) appear to endorse such views (see p. 161 with 154). Socrates and his ethic are a voice in the wilderness. B. relies heavily on subtle dramatic and literary detail in weaving his exegesis. He gives the impression of being more excited by an interesting interpretative possibility than fastidiously concerned with nailing things down. This can sometimes result in intriguing but under-motivated interpretations (e.g. his claim that Glaucon and Adeimantus remain firmly entrenched in the pleonectic ethic despite their approval of Socrates' defence of justice in the dialogue at pp. 21-2). B. is at his best when the interpretative scope is narrow and textually focused. In these contexts he is a maestro at unpacking the possible interpretative implications of literary and dramatic detail (e.g. his enlightening discussion of Socrates' interpretation of the vexed 'willingly' line of Simonides' ode at pp. 88-94). The book is written in a lively style and is infused with humour and wit. B.'s delight in hunting down the subtle twists and turns of Platonic drama and wringing out their every interpretative drop is palpable.

This is an international conference on Plato's Theaetetus. It will take place in Alghero (Sardinia, Italy) from the 20th to the 22th of June 2019. Alghero is a wonderful city, on the sea. In case you are interested in Plato, you're very welcomed! The Conference is public and open to all who want to follow it.

Este ensaio fala de uma possível (porém improvável) interpretação para a anedota a respeito de Tales, contada por Sócrates no Teeteto de Platão. Ele recupera também a fábula sobre o astrônomo de Esopo, que é muito provavelmente uma de suas principais fontes. A discussão das possibilidades de interpretação é uma sugestão de Hans-Georg Gadamer, em que ele aventa a possibilidade de que Tales não teria caído no poço, mas descido deliberadamente para melhor observar os astros. Discute também o papel da serva trácia, como iniciadora de um diálogo e do próprio diálogo como estando nas origens da filosofia.

Wonder (thaumazein) is the beginning of philosophy. This well-known formula can be grasped for the first time in Plato’s Theaetetus (155d). The standard interpretation of this passage takes wonder as a positively connoted, transitive starting point of the epistemic process insofar as wonder stimulates the will to investigate. The present article challenges this view by presenting an aspect of Theaetetus 155d that has been overlooked ever since. Via a reconstruction of the dialogue’s context, broader philological arguments and an implementation into Plato’s systematic approach, the article aims to show that the Platonic conception of thaumazein is to be understood first of all as a result of sophistry: Wonder isn’t a transitive starting point but a hermetic perplexity that remains gazing at the sophist in admiration (thaumazein) and that has to be overcome. Thus, wonder is also the beginning of philosophy because it is the result of sophistry and (Platonic) philosophy arises from opposition to the latter.

This edited volume brings together contributions from prominent scholars to discuss new approaches to Plato’s philosophy, especially in the burgeoning fields of Platonic ontology and psychology. Topics such as the relationship between mind, soul and emotions, as well as the connection between ontology and ethics are discussed through the analyses of dialogues from Plato’s middle and late periods, such as the Republic, Symposium, Theaetetus, Timaeus and Laws. These works are being increasingly studied both as precursors for Aristotelian philosophy and in their own right, and the analyses included in this volume reveal some new interpretations of topics such as Plato’s attitude towards artistic imagination and the possibility of speaking of a teleology in Plato.

Focusing on hot topics in the area, Psychology and Ontology in Plato provides a good sense of what is happening in Platonic scholarship worldwide and will be of interest to academic researchers and teachers interested in ancient philosophy, ontology and philosophical psychology.

Deiformity, likeness to God, is the goal of Plato, Aristotle, the Neoplatonic philosophers and their Jewish, Islamic and Christian heirs.
We meet here again a problem which Plotinus takes up over and over: when we look at something, even if that something is ourselves, we externalize it. In consequence when the object is ourselves, we falsify our knowledge. Is this why Plotinus never ceases to push towards the One? Only there has subject and object become identical. There we “need no longer look outside for [our] vision of the divine being.” A description of the Union is the coming of a light so that the seer, what she sees, and the light by which she sees are the same. This Augustine also sought.

Resenha de PLATÃO. Teeteto. Texto estabelecido e anotado por John Burnet. Tradução, apresentação e notas de Maura Iglésias & Fernando Rodrigues. Rio de Janeiro; São Paulo: Editora PUC-Rio; Edições Loyola, 2020. 264 pp. ISBN (PUC-Rio): 978-65-991801-0-1. ISBN (Edições Loyola): 978-65-5504-040-1.

Plato famously promised to complement the Sophist and Statesman with another work on a third sort of expert, the philosopher—but we do not have this final dialogue. Mary Louise Gill argues that Plato promised the Philosopher, but did not write it, in order to stimulate his audience and encourage is readers to work out, for themselves, the portrait it would have contained. The Sophist and Statesman are themselves members of a larger series starting with the Theaetetus, Plato’s investigation of knowledge, and the whole series relies on the Parmenides, the second part of which presents a philosophical exercise, introduced as the first step in a larger philosophical program. Gill contends that the dialogues leading up to the missing Philosopher, though they reach some substantive conclusions, are philosophical exercises of various sorts designed to train students in dialectic, the philosopher’s method; and that a second version of the Parmenides exercise, closely patterned on it, spans parts of the Theaetetus and Sophist and brings the philosopher into view. This is the exercise about being, the subject matter studied by Plato’s philosopher. Plato hides the pieces of the puzzle and its solution in plain sight, forcing his students (and modern readers) to dig out the pieces and reconstruct the project. Gill reveals how, in finding the philosopher through the exercise, the student becomes a philosopher by mastering his methods. She shows that the target of Plato’s exercise is internally related to its pedagogical purpose.

On Plato's use of the definition of clay in the Theaetetus to model the definition of knowledge as expertise, the wide kind to be divided in the search for the expertise of the sophist and statesman in the dialogues that continue the series leading up to the promised but missing dialogue Philosopher.

Le Théétète fait partie des nombreux dialogues dans lesquels Platon ne montre que des arguments débouchant sur une aporie que les commentateurs essaient de comprendre. Le présent article est axé sur l’exemple du passage sur la possibilité de l’opinion fausse, dans la deuxième tentative de définir la science par l’opinion vraie. À cet égard, la démarche adoptée vise à démontrer la présence d’un présupposé commun aux cinq arguments échoués afin de faire ressortir la finalité de cette série d’échecs : pour parler du faux, il faut introduire la mise en relation des éléments, alors que, sans considérer le rôle de la mise en relation, il est impossible de démontrer le faux. Les échecs successifs des arguments dans le Théétète servent ainsi à mettre en évidence la condition nécessaire à toute évocation du faux, en montrant les conséquences de son absence afin de préparer la discussion sur le faux dans le Sophiste.

Through Professor Arun Iyer’s parallel reading of Plato’s Theatetus, Heidegger’s 1931/32 lectures On the Essence of Truth, and the early modern political wrings of Raja Rammohan Roy, Heidegger’s 'novel way of relating to the historical past' can be described according to a logical movement through three layers of the significance of the un-happened : 1) that which did not happen; 2) that which still yet happens through the enduring presence of the un-happened ; and 3) that through which this enduring happening of the un-happened presents itself.

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.

I defend four main theses: (1) Knowledge, in Plato’s vocabulary, is a kind of conceptual competence, involving ‘knowing what it is’ about something like virtue or justice; (2) There is a corresponding special meaning of the verb “is” that occurs in the expression “knowing what it is”, which is key to understanding what Plato means by claiming that Forms have a superior kind of being. (3) When one knows ‘what it is’ about such concepts, one knows neither a proposition, or set of propositions, nor an object, but something like a type. Plato’s term is eidos. Plato rightly notes that, in ordinary experience, we never encounter types, but only tokens. (4) Although encountering such tokens does not constitute knowledge, it can provide a ladder whereby philosophers can attain a better grasp of the truths in question. Plato’s preferred philosophical method turns out to be an ‘iconic method’,— consciously using images and particulars as stepping stones in the enquiry.
Via case studies from the Meno, Republic and Theaetetus, I establish that these theses are not only compatible with the texts, but render some otherwise puzzling passages intelligible. I show that Plato diagnoses, and deliberately sidesteps, the impasse of Socrates’ fruitless quest for definitions, developing a new method inspired by geometry’s ability to deal pictorially with indefinable lengths. The book offers a novel picture of Plato as resisting and overcoming, not following, the Socratic obsession with definitions, and adopting, not resisting, the use of pictorial proofs and imagery

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.

Paper read at Lausanne in 1988. My paper deals primarily with Sextus Emp. Adv. Math. VII 61-64, a passage dealing with Protagoras but not included either in Diels-Kranz, Untersteiner 1949, Capizzi 1966, or Sprague 1972, nor in Guthrie or Kerferd's Sophistic Movement. But also VII 389-91 is worth being re-considered as additional evidence of a debate on Protagoras' homo mensura statement, with objections and a counter-argument on the part of Protagoras himself. In my opinion, these passages can well count as evidence of something said by Protagoras and does not deserve to be put aside.

Although Bertrand Russell's work in epistemology is viewed as having been significantly surpassed by his successors, it still provides a rewarding context in which to discuss and examine the problem of knowing another person.  The distinction between knowledge by acquaintance and knowledge by description is critically revisited and then applied to how it is that Theodorus and Socrates respectively could be said to know Theaetetus as a person in Plato's "Theaetetus."

A striking, though largely unremarked, aspect of the Theaetetus is the friendship of Protagoras and Theodorus, which is frequently highlighted,  (at one point, Socrates even calls Protagoras Theodorus’ “teacher”).  Why this should be the case is something of a mystery given their radically divergent intellectual inclinations.  Protagoras, the great sophist, is the “father” of the homo mensura. Theodorus, by contrast, fancies himself a strictly neutral bystander at a philosophical duel. He is “not used to conversation of this sort” (146b3), and admits that “for some reason” he had long since turned away from “bare logoi to geometry” (165a1-3).  In this paper, I argue that Plato aims to demonstrate that sophistry is related to a kind of ignorance of one’s self that can be lodged at the heart of his own mathematically inclined conception of paideia as periagogē.

Di Girolamo, S., “Оἱ τοῦ ὅλου στασιῶται. Il 'Teeteto' su Parmenide e Melisso in rapporto al problema mereologico”, in J. Mansfeld et al., Melisso tra Mileto ed Elea, ELEATICA 5, a cura di M. Pulpito, Academia Verlag, Sankt Augustin, 2016, pp. 137-144 (ISBN:978-3-89665-695-7).

Towards the beginning of the self-refutation argument, at 171a1-6, Socrates reaches the conclusion that even if Protagoras believes his Truth, it is still more false than true. This conclusion is puzzling in that it is unclear why it should worry a Protagorean. I argue that the passage presents a genuine dilemma between Protagoras’ claims that we can judge only of our own private worlds and that cities have collective judgements.