Theaetetus

by Plato, Francis Macdonald Cornford (Translator)

What is knowledge? A systematic treatment of this question takes the form of a dialogue between the great philosopher Socrates and his student, Theaetetus. They explore a variety of answers, including knowledge as perception; knowledge as true belief; knowledge as true belief plus an account (i.e., a justified true belief); as well as variations on each of these possibilities. Like most Socratic dialogues, it ends without a definitive answer, leaving the subject open for the reader's further consideration.
One of Plato's later masterpieces, the Theaetetus poses eternal questions that keep the dialogue relevant not only for students of philosophy but also for every serious reader and thinker. This edition, translated by the noted classical scholar Francis M. Cornford, features extensive commentaries by the interpreter that provide helpful background information and valuable insights.

Genres: Philosophy, Classics, Nonfiction, Ancient, Ancient History, Greece, History

176 pages, Paperback

First published January 1, 370

About the author

Plato (Greek: Πλάτων), born Aristocles (c. 427 – 348 BC), was an ancient Greek philosopher of the Classical period who is considered a foundational thinker in Western philosophy and an innovator of the written dialogue and dialectic forms. He raised problems for what became all the major areas of both theoretical philosophy and practical philosophy, and was the founder of the Platonic Academy, a philosophical school in Athens where Plato taught the doctrines that would later become known as Platonism.
Plato's most famous contribution is the theory of forms (or ideas), which has been interpreted as advancing a solution to what is now known as the problem of universals. He was decisively influenced by the pre-Socratic thinkers Pythagoras, Heraclitus, and Parmenides, although much of what is known about them is derived from Plato himself.
Along with his teacher Socrates, and Aristotle, his student, Plato is a central figure in the history of philosophy. Plato's entire body of work is believed to have survived intact for over 2,400 years—unlike that of nearly all of his contemporaries. Although their popularity has fluctuated, they have consistently been read and studied through the ages. Through Neoplatonism, he also greatly influenced both Christian and Islamic philosophy. In modern times, Alfred North Whitehead famously said: "the safest general characterization of the European philosophical tradition is that it consists of a series of footnotes to Plato."

Reviews

[Luís · Rating 5 out of 5]

Socrates teaches us the method of maieutics, that is to say, that, just as a midwife does not give birth to the child of a pregnant woman, Socrates does not "create" knowledge but "extract" it from the individual through philosophy. Experience is within us (the famous "know yourself" from the temple of Delphi), and philosophy - or rather wisdom, a word that keeps a connection to "practice" - only manifests these inner truths, reflections of Archetypical ideas.
It is also vital to the Platonic ideas in epistemology (the science of knowledge) because, by Theaetetus, we raised various questions on the legitimacy of the modes of understanding (sensation, judgment, etc.).

[Roy Lotz · Rating 4 out of 5]

… wonder is the feeling of a philosopher, and philosophy begins in wonder.

As I slowly make my way through Plato’s works, this dialogue stands out for being by far the most technical. Plato discusses a question that has dogged every philosopher from antiquity to modern times: What is knowledge? His interlocutor—in this case a bright boy who is the dialogue’s namesake—first proposes that knowledge is perception. This was to be the starting point of both Descartes and Hegel, among others; and like these later thinkers, Socrates sees fit to reject this idea. Knowledge cannot be perception because the same thing can be perceived as, for example, both hot and cold; and, besides, sometimes we have realistic dreams.

Of course, we could potentially get around this by making both knowledge and reality wholly relative to the individual. This way, no one could ever be wrong. But then the very idea of “knowledge” would seem superfluous; and, anyway, we run into awkward situations, such as if I say “you are wrong.” Purely subjective standards cannot help arbitrate between competing claims of truth. Clearly there is another element missing.

Socrates examines a situation in which a person answers a question incorrectly, even though in a sense they “know” the answer. This happens when one makes an absent-minded mistake in calculating, for example, or when one simply misremembers. Somehow, the knowledge is “in” the brain, but was not retrieved properly. So does the person “know” and “not know” at the same time? Or is the knowledge, properly speaking, not the answer itself, but the process that allows us to retrieve the answer?

Perhaps it is both; and knowledge consists both in an answer and the judgment required to arrive at the answer. But here Socrates’s hatred of rhetoric—the art of convincing—comes into play. He notes that a person may arrive at the correct answer without exhibiting true judgment. This may happen, for example, when somebody is convinced based on authority or appeals to emotion. Human judgment, in other words, arrives at conclusions by extra-logical means.

Then, perhaps, real knowledge must give a logical account of how it arrived at its conclusion. But what would this logical account consist of? An enumeration of the basic elements of the answer? It may be true, however, that the basic elements (letters in a word, for example) are meaningless in themselves and only meaningful when put together. Or perhaps a logical account means being able to define how something is differentiated from other things? But this leads to circular reasoning, since the explanation of the answer will presuppose the answer. (What is the brightest object in the sky? The sun is, because I observe it is brighter than everything else.)

Well, I think you can see where this is going. Like in many of the early Platonic dialogues, this one serves to show the difficulty in arriving at a solid conclusion, rather than advocating any one theory. However, this dialogue is far more technical and lengthy than any of the early dialogues. The nature of the work is entirely different: the dialogue is concerned with a theory of epistemology rather than with reforming the people of Athens by exposing their ignorance. As an afterthought, it is unclear how Plato could square this open-ended discussion of knowledge with his own theory of forms, where true knowledge means knowing the ideal forms. He was certainly a complex thinker, to say the least.

The most famous part of this dialogue is the “midwife” metaphor for the Socratic method. According to the old philosopher, he himself is barren of ideas, but just helps others bring them into the world—like a midwife. It is a wonderful image of the teacher. But it would be difficult to argue that is an apt description of Socrates’s method in this dialogue. He does the vast majority of the talking and originates all of the major developments in the conversation. His partners are mostly just along for the ride. Perhaps Socrates was a tad more fertile than he would have us believe.

[Riku Sayuj · Rating 5 out of 5]

Epistemological Idiots

Here Plato engages with the concept of ‘knowledge’ and ‘understanding’ as in many other dialogues, but Theaetetus is often hailed as ‘Plato’s most sustained study of epistemology,’ and is a deep investigation into the question ‘What is knowledge?’ As such, it is the founding document of what has come to be known as ‘epistemology’, as one of the most important branches of philosophy and went on to influence Aristotle, the Stoics and the modern geography of the field.

In comparison with most Platonic Dialogues, Theaetetus is a complex and difficult work of abstract philosophical theory and attempting to summarize would only serve to make it even more so. The difficult topic of epistemology and its many twists and turns are best left to Socrates’ expert hands. Here I will only try to outline my understanding of how this dialogue fits into Plato’s overall objectives.

Socrates’ abiding passion was the question of practical conduct, and to be able to have any workable theory on conduct and the ‘good life’, it is not acceptable that truth is relative — if there is no stable norm, no abiding object of knowledge, Socrates (and thus Plato’s) basic objective collapses. This is why it was essential to be convinced that ethical conduct must be founded on knowledge, and that that knowledge must be knowledge of eternal values which are not subject to the shifting and changing impressions of sense or of subjective opinion, but are the same for all men and for all peoples and all ages, eternal.

This conviction that there can be knowledge in the sense of objective and universally valid knowledge is what animates the spirit of Theaetetus — to demonstrate this fact theoretically, and to probe deeply into the problems of knowledge, asking what knowledge is and of what.

Keeping with this objective, in the Theaetetus Plato's first object is the refutation of false theories. Accordingly he sets himself the task of challenging the theory of Protagoras that knowledge is perception, that what appears to an individual to be true is true for that individual. His method is to elicit dialectically a clear statement of the theory of knowledge implied by the the epistemology of Protagoras, to exhibit its consequences and to show that the conception of "knowledge" thus attained does not fulfill the requirements of true knowledge at all, since knowledge must be, Plato assumes, (i) infallible, and (ii) of what is.

Sense-perception is knowledge fails spectacularly (and quite satisfactorily for Plato) in this examination as it is neither the one nor the other. Sense-perception is not, therefore, worthy of the name of knowledge. It should be noted how much Plato is influenced by the conviction that sense-objects are not proper objects of knowledge and cannot be so, since knowledge is of what is, of the stable and abiding, whereas objects of sense cannot really be said to be but only to become.

This first of Theaetetus’ (Theaetetus was a famous mathematician, Plato’s associate for many years in the Academy) three successive definitions of knowledge — that knowledge is simply ‘perception’ — is not finally ‘brought to birth’ until Socrates has linked it to Protagoras’ famous ‘man is the measure’ doctrine of relativistic truth, and also to the theory that ‘all is motion and change’ that Socrates finds most Greek thinkers of the past had accepted, and until he has fitted it out with an elaborate and ingenious theory of perception and how it works. He then examines separately the truth of these linked doctrines and, in finally rejecting Theaetetus’ idea as unsound, he advances his own positive analysis of perception and its role in knowledge:

Thus Socrates proceeds to the next two definitions of knowledge — that ‘Knowledge is simply "True Judgment”’ and that ‘Knowledge is True Judgment plus an "Account" of it.’ After systematic exploration of these ideas (with a few amusing digressions) and rejecting them as unsound Socrates paves the way toward an acceptable theory of Forms, to be explored further in dialogues such as Parmenides and The Republic .

Epistemological Idiots? Not Quite.

Once we reject the three proposals and reach the aporetic conclusion of the dialogue, our first impulse might be, as with all epistemological explorations, to conclude that Socrates has proved that it is impossible to define ‘what is knowledge’ and hence, by extension, the impossibility of knowledge itself. I almost laughed with triumph at this nihilistic ending until I was put in my place by reading commentaries on the subject. For a quick flavor:

SOCRATES: And so, Theaetetus, if ever in the future you should attempt to conceive or should succeed in conceiving other theories, they will be better ones as the result of this inquiry. And if you remain barren, your companions will find you gentler and less tiresome; you will be modest and not think you know what you don’t know. This is all my art can achieve — nothing more.

Instead, a more nuanced reading of Theaetetus’ conclusion by situating it among the Platonic corpus will tell us that the conclusion to be drawn is not that no knowledge is attainable through definition, but rather that the individual, sensible object is indefinable and is not really the proper object of knowledge at all. The object of true knowledge must be stable and abiding, fixed, capable of being grasped in clear and scientific definition, which is of the universal, as Socrates saw. In the Theaetetus he shows that neither sense-perception nor true belief are possessed of both these requirements; neither, then, can be equated with true knowledge.

This is the real conclusion of the dialogue, namely, that true knowledge of sensible objects is unattainable, and, by implication, that true knowledge must be knowledge of the universal and abiding, which must be, as we have said, (i) infallible, (ii) of what is.

The key to understanding Theaetetus is to accept that Plato has assumed from the outset that knowledge is attainable, and that knowledge must be (i) infallible and (ii) of the real. True knowledge must possess both these characteristics, and any state of mind that cannot vindicate its claim to both these characteristics cannot be true knowledge. It follows, then, that it is the universal and not the particular that fulfills the requirements for being an object of knowledge. Knowledge of the highest universal (beauty, goodness, justice, courage, etc.) will be the highest kind of knowledge, while "knowledge" of the particular will be the lowest kind of "knowledge." This connects us directly to the famous line analogy of The Republic and paves the way for The Theory of Forms.

Theaetetus is a valuable but difficult dialogue to be familiar with since Plato explores epistemology without letting on his intentions and this might prove difficult to readers who treat this dialogue as standing by itself. Instead it needs to be treated as part of a continuum, that started with Parmenides and is carried forward in The Sophist and The Statesman (the next two parts of the ‘trilogy’) and on to The Republic, destined to trouble Plato for the rest of his career, never being resolved satisfactorily enough.

[path · Rating 4 out of 5]

Socrates is usually an entertaining character in most of Plato’s dialogues, and is here as well. I have a vivid picture of him as a scruffy, “snub nosed” guy with “bulging eyes” (209c) that you might try to avoid if you saw him coming down the road. Except that he really is sincere and nice … a bit chatty, but generally a good conversationalist if you have a few hours to spend and don’t mind looking like an ignoramus at times.

This dialogue has Socrates talking with Theaetetus about the nature of knowledge. And in Socrates’ words, he is playing the role of “midwife” helping Theaetetus “give birth” to his notions of knowledge. I’m not making this up. Socrates:

When I ask a question, set about answering it to the best of your ability. And if, on examination, I find that some thought of yours is illusory and untrue, and if I then draw it out of you and discard it, don’t rant and rave at me, as a first-time mother might if her baby was involved (151c-d)

Yes, there’s some questionable stuff there, but the way Socrates envisions the role of midwifery and relates it to an inquiry on the concept of knowledge strikes me as important. However, I’m getting ahead of myself.

Over the course of the dialogue, Theaetetus offers three different definitions of knowledge:

1. “Knowledge is perception”
2. “Knowledge is true belief”
3. “Knowledge is true belief with a rational account”

Through dialogue with Theaetetus, Socrates troubles each these positions in a variety of ways.

Knowledge can’t be perception because, among other things the thing being perceived is continually changing, as is the perceiver (183b). Furthermore the thing is being perceived by different perceivers, all of whom are changing and seeing that thing from different angles. This process cannot yield an object that is commonly perceived in exactly the same way (156d). This position leads to a kind of radical relativism where we cannot know anything about anything except what the thing is to us at any given moment (161d). This position is unfairly (I think) attributed to the sophist Protagoras who famously claimed that “man is the measure of all things.” Socrates takes this sophistic proclamation to mean that “a man” is the measure of all things and so “this man” and “that man” are both equally right about a thing even if their positions differ (171c). I think Protagoras could be read as saying that people (i.e., Man … mankind … humankind) know what they know only insofar as they are capable of knowing at all, through our senses and our ability to make rational sense out of experience (probably a Kantian revision of what Protagoras may have meant).

Neither can knowledge be true belief (187b) if only because we can hold beliefs that are mistaken. I can mistake things that I cannot perceive well enough to distinguish them (194a). I can hold beliefs on the basis of what appears to be true but isn’t. It is also the case that beliefs seem to require separation from knowledge because you cannot hold a belief that is contrary to what one knows (190b). For example, if I know that this medicine will cure what ails me then I cannot simultaneously believe otherwise — it would not be a “true” belief. Someone else could hold that belief as “true” however. Socrates goes on to develop this idea by suggesting that when we know something to be true, the direct encounter with that truth impresses itself like the mark of a signet ring in wax (195a) and beliefs that do not conform will fill that space incompletely. Strangely, though, Socrates insists on extending this analysis to purely conceptual things like number (e.g., 11 and 12) in ways that I don’t get because we can understand those concepts by definition alone. There are no impressions to get wrong.

Finally, it is unclear whether knowledge could be true belief supported by a “rational account” (202c) in which we rationalize our beliefs as being those made understandable through some rational process of justification. This approach ends in indecisiveness because it seems that whatever could be offered as a rational account must come to rest on beliefs and perceptions that can be challenged for all the reasons that Socrates dismantled Theaetetus’s first two definitions of knowledge.

It might seem dissatisfying to end the dialogue here, but I think there is more resolved about knowledge than it might appear, especially if one looks at the very form of this dialogic exchange between Socrates and Theaetetus as reflective of a kind of knowledge that does not rest in definitive statements. Knowledge is a process of knowing and claims deriving from that are provisional. Socrates hints at this version of knowledge early on by defining a “proper inquiry” as “sitting down together in a spirit of goodwill, not with hostile and aggressive intensions” (168b) in order to correct errors in each others’ judgements (168a). Socrates continually encourages Theaetetus to take risks and when he does, Socrates praises him for not holding back and for being willing to have his position picked apart and changed (204b).

Each of the definitions that Socrates engages with, and dismisses, illustrate that it is problematic to treat knowledge as a thing that one has or doesn’t have (197c). If we think about knowledge as something that one believes and offers as true and submits that knowledge as provisional, subject to the test of experience, sensation, and the scrutiny of other knowing and sensing beings then it is not problematic if knowledge is true or false or built on beliefs that are true or false or built from perceptions that are complete or incomplete. Knowledge is something you practice rather than have.

So perhaps there is something to Plato’s odd use of the “midwife” as a metaphor in that it highlights the role of an interlocutor or someone who assists in the creation or bringing forth of knowledge. That is sort of the definition of knowledge that I thought was missing from this formulation and was the role that Socrates was playing from the very start.

This returns us to Socrates’ analogy of the wax tablet in which he cautions that it is better for the wax to be warm and open to change rather than hard and resistant to change (195a). I sure would like to live in a world like this.

P.S. - Also, the concluding essay by Robin Waterfield is really excellent, if a little "in the weeds" at times.

[Xander · Rating 3 out of 5]

The Theaetetus is one of Plato’s more famous dialogues. According to experts, it dates from Plato’s late period of writing and it fits in with his Republic. But there are important differences between both works.

In the Republic, Plato expounds his famous theory of Forms. According to him, knowledge consists in understanding the Forms – using the mind’s eye, so to speak – which are intelligible but insensible. In other words, our senses lead to opinion, not to knowledge, while only reasoning can show us the true objects.

But in the Theaetetus, Plato seems to forget all about his earlier theory of Forms and he turns sceptical when it comes to knowledge. In short: after refuting various conceptions of knowledge, Plato and his conversational partner, Theaetetus, come to the conclusion that it is impossible to define what knowledge is. But Theaetetus leaves the dialogue with the fine remark of Plato that at least he now knows that he doesn’t know anything.

The dialogue is at times hard to follow, but not impossible to understand. And many times in Theaetetus Plato is able to interrupt the current dense dialogue with funny interludes.
In essence, Plato discusses (through Socrates) three conceptions of knowledge, which he eats refutes.

1. Knowledge is perception.
2. Knowledge is true judgement.
3. Knowledge is true judgement with an account given of it.

In the first half of the dialogue, Plato deals with the conception of knowledge as perception. In doing so, he deals with Heraclitus’ theory of flux (i.e. change) and Protagoras’ relativism.
Heraclitus’ flux theory of the world is, by definition, impossible as knowledge. If everything is continuously in change (something Heraclitus never claimed, but alas), it is impossible to arrive at a reliable description of things. Describing things in the world requires a certain stability in spacetime, since it is only by convention that words resemble objects – if objects continuously come and go, there’s no resemblance to obtain. To me, this seems to be a straw-man, since Heraclitus never claimed everything is flux, he actually claimed behind all the apparent flux there’s a stable reality, only to be known through the intellect. So in this sense, Heraclitus actually should be seen as a precursor to Plato’s own theory of knowledge.

Protagoras’ relativism says that ‘man is the measure of all things’, which leads to a subjectivist view on reality. If each person senses and perceives the world from his/her own perspective; and each person has his/her own intellect; then each person knows the world. This leads to as many true judgements as there are subjects perceiving the world, and even to the different true judgements for the same subject at different times. A claim bishop Berkeley would make in the eighteenth century (Berkeley founded his subjectivism in God’s perfection – since God perceives everything instantaneously, there is a Being perceiving the World – offering a stop to extreme relativism. Of course, everything now hinges on the existence of this Being, which itself is problematic).

Plato rightfully asks the simple question: why is not a buffoon the measure of all things? Or a tadpole? But more seriously, if everyone has true beliefs based on his/her own perceptions, there are many contradicting judgements out there. This is logically impossible: a judgement is either true or not. If person A beliefs a judgement to be true and person B beliefs the same judgement to be false, there is a contradiction. And contradiction is the criterion with which we judge the truth of a proposition – a proposition that contradicts itself cannot be true. So if Protagoras claims all judgements are true, and I claim this proposition is false, there’s a problem.

Plato then proceeds to show how the existence of experts refutes Protagoras’ position. If all beliefs are true, why do we need experts? Why do we need Protagoras as a rhetorician if we all can know the truth simply by perceiving? We rely on experts precisely because they have – on average – more true beliefs about a subject than we, as laypeople, do. He concludes the section by refuting Theaetetus’ original claim that knowledge is perception – perception is mere experiencing sense-data. It is entirely possible to know something without perceiving it, or to perceive something without knowing it.

So, Plato takes on the second conception of knowledge: knowledge is true judgement. But, as he lets Socrates exclaim at the end of this piece of dialogue, it is entirely possible to make a true judgement without knowing about it – if I claim the whole day that it’s 3:15, I still am right twice a day. It doesn’t mean I know what I’m talking about.

Socrates has two analogies of making true judgements, which both leave much to be questioned. First, he uses the analogy of a wax tablet. Our mind is a wax tablet and perceptions leave imprints on it – this is what we call memory. Then, when we perceive something and associate it with the correct memory, it is a true judgement. When we associate the current perception with a wrong memory, this is false belief. But this misidentification-theory of knowledge doesn’t work well, so Socrates offers a second analogy: the mind as an aviary.

Possessing knowledge is like possessing birds – only by putting them in a cage do we possess them. Grasping something (i.e. catching birds) isn’t the same as possessing something (i.e. possessing birds). The birds fly in the aviary, along with birds we didn’t know were in the aviary, and when we make judgements we either pick the right (known) bird or the wrong (unknown or another) bird. In the first instance, we make a true proposition, while in the second instance, we make a false proposition. This doesn’t tell us – at all – how the birds (known and unknown) got in the cage to begin with. A problem later philosophers, like John Locke and David Hume, would seize upon and offer their own theories of knowledge. In short, Plato claims ‘knowledge is true judgement’ is false but he doesn’t offer a satisfying answer to the problem.

The last part of the dialogue sees Socrates defending the claim that ‘knowledge is true belief with an account’. This, in short, means that in order to count as knowledge, something has to be a true belief and it has to be able to be communicated in words (i.e. logos). Socrates here offers a third analogy, that of the dream (known as ‘Socrates’ Dream’). According to this, knowledge consists in defining objects in terms of their parts. But this is problematic, since how do we define the parts? According to Socrates, the parts are unknowable, but the wholes (build from these parts) are knowable.

So Socrates attacks this conception of knowledge on the point that it is unsatisfying (or impossible?) to know something that consists of unknowable parts – that is, if knowledge presupposes communication (logos). The dialogue ends with a dilemma: if knowledge consists in distinguishing things from other things (which, if not the case, would mean all things are the same), then does knowledge consist in judging the crucial distinction of a thing? But if this is so, then everyone who perceives and consequently judges A differs from B knows A. Which brings the problem of reliability and expertise (cf. Plato’s attack on Protagoras) back full-circle. Or else, does knowledge consist of knowing which quality distinguishes A from B? But this, then, presupposes knowing, which is the thing Plato set out to prove from the beginning (i.e. begging the question).

This problem leads Socrates to conclude that it’s impossible to define knowledge, at least as perception or as true judgement (with or without further conditions). And now the young Theaetetus, although still not knowing what knowledge is, at least knows what it’s not. And this is as much as we can hope for, according to Socrates, at least.

A pressing question at this point would be: is it possible to know something without being able to define what knowing is? And does existence preclude knowledge? In short: is this not simply a pseudo-problem, although a supposedly important one? One can see the problem in modern-day science – ever since the nineteenth century, science broke away from philosophy and just went on discovering all kinds of things. Nowadays, there’s no scientist who uses or needs to use philosophy to gather knowledge. This is pragmatism in full force: true is that which is the most useful to explain the data and to manipulate nature. It’s not for nothing that the early twentieth century, the most recent era with the biggest scientific breakthroughs, led to new ways of tackling the old philosophical chestnut of knowledge. Logical-positivism, falsificationism, paradigm-shift-theories, etc. are all philosophical attempts to circumvent Plato’s problem of defining knowledge.

Anyway, the Theaetetus is an interesting read, although at times a bit abstract. Being familiar with Pre-Socratic ideas (especially Protagoras, Heraclitus and Empedocles) can be helpful, as well as being familiar with some of Plato’s other views of knowledge (e.g. his theories as outlined in Republic and Phaedo). It’s still unclear to me how Plato’s different conceptions of knowledge connect with one another – did he think his theory of Forms is true? Did he conclude there’s no theory of knowledge possible? I guess we’ll never know.

[Zadignose]

Hello philosophy. You've just convinced me that I don't know what knowledge is.

Okay, not true, actually, you've pushed me in the direction I was already inclined to go, and my concept of knowledge is pretty much what it already had been.

Thus I am guilty once again of seeking out philosophy based on the presumption that it will confirm me in what I think I already know, rather than seeking to be corrected.

I'll think some more, though.

[Raquel · Rating 5 out of 5]

Que livro tão bom ❤ que conversa tão incrível a de Sócrates, Teeteto e Teodoro. A grande questão em debate é: " o que é o saber?". Sócrates procura a genealogia do saber [ como Foucault construiu a sua arquelogia do saber]. A exploração teórica da epistemologia "before it was cool."
A frescura deste diálogo impressiona, e hoje podia ter sido o tema de uma conversa entre amigos ou desconhecidos [embora, actualmente, a dialética do conhecimento, não ocorra assim tantas vezes].
Num jeito mais shakespeariano diria: "saber ou não saber, eis a questão."
O diálogo tem ainda toques de humor por parte de Sócrates e Teodoro. No fim permanece uma grande humildade perante a volatilidade do saber.
Mas apesar da humildade, o imperativo kantiano deve sempre prevalecer: "sapere aude!"

N.B: esta edição facilita muito a compreensão do texto.
~

Sócrates - "É o que te vou dizer e não vai ser uma resposta simples: que nada é um, por si e em si, e não poderias nomear algo com correção, nem indicar alguma qualidade; mas, se chamares a algo grande, também aparecerá pequeno, se chamares pesado, aparecerá também leve, e assim também todas as coisas, dado que nada é unidade, algo ou qualidade. Partindo da deslocação, do movimento e da mistura de umas com outras, todas as coisas se tornam naquelas que estávamos a dizer; não as chamando corretamente, pois nada nunca é, mas vai-se tornando sempre."

Sócrates - " O quê? Será que o que parece a ti é o mesmo que aparece a outro homem? Manténs isto a todo custo, ou preferes admitir que nem para ti próprio as coisas são as mesmas, porque nunca és igual a ti próprio? "

[Czarny Pies · Rating 2 out of 5]

"Theaetetus" merits two stars on the Platonic scale; it is to say I consider it to be one of Plato's less important works. Plato has several works (the Symposium or the Republic for example) which are presented early in the undergraduate years because they are pertinent and clear. "Theaetetus" is murky at best and finishes in a frustrating aporia or impasse. It is hard for any reader to know what point Plato was trying to make. He reviews three theories of knowledge, exposes the weaknesses of each and then refuses to choose.
Despite my frustration "Theaetetus" is still a work of Plato and thus of great importance. The editor of my edition of "Theaetutus" describes it as a founding work of epistemology that had a great influence on Kant. Paul Ricoeur in "La Vive Métaphore" said that it raises a number of important issues that are important in the field of semiotics. Unfortunately I lacked the necessary baggage when I undertook to read it. Read in isolation as a Platonic dialogue rather than as a precursor of modern works, it is a rather muddled piece.

[Tohid hadinejad · Rating 5 out of 5]

نخستین تلاش های (البته تلاشهایی بی سرانجام) برای پاسخ به این سوال که دانش چیست و ما چه می دانیم و آنچه می دانیم چیست؟

[Trevor · Rating 4 out of 5]

This is much harder work than your average Socratic Dialogue by Plato. I found I really had to concentrate on some of the twists in the argument and have to say that I found some of the footnotes quite distracting in this edition. As someone who does not read Ancient Greek – part of the reason I’m reading Plato in translation – it is a little hard to know why my reading needs to be interrupted to be told the translator is reading some word in Ancient Greek as it is in the manuscript.

I got half way through the essay in the back of this and have now have given up. It is basically working its way through the text and like I said, I struggled over the text enough to not feel like I’m really getting much extra out of the essay to justify reading on.

This is perhaps one of the first works in the history of Western Philosophy on Epistemology – or the Theory of Knowledge. It is an explanation and critique of both Heraclitus (all is flux – you can’t step in the same river twice) and mostly Protagoras (Man is the measure of all things). I can’t remember now if in one of the dialogues in The Trial and Death of Socrates we learn there that Socrates considered himself a mid-wife or if this is just one of those things you get taught in introductory philosophy. Either way, there is a long discussion of what Socrates saw as his role in helping – particularly young men come to grips with philosophical ideas. This is a late dialogue of Plato’s and as such is not at all what you might expect of Plato from any intro course you might have done. The world of forms has no place here. In fact, there were repeatedly times while reading this when I expected Plato to just say, “Knowledge is a kind of recollection of the forms we knew before birth”. That he doesn’t say anything remotely like this in this dialogue is fascinating in itself.

What is even more fascinating is that there is no conclusion to what knowledge is in this dialogue. There are some very tentative steps taken towards the idea that knowledge is the production of rational statements – but even this is discarded.

Other alternatives are that knowledge is perception or memory.

What is interesting is that whenever we are truly stuck – we turn to metaphors. In this memory is first described as a kind of wax in which memories are imprinted. Then memories are compared to a collection of birds that one keeps in an aviary. This is my favourite as it is used to explain why we might mistakenly say that seven plus six equals twelve – that is, we have grabbed at and caught the wrong bird in the aviary of our mind. Lovely image.

Like I said, this dialogue was hard work and not the place to start if you haven’t read any Plato before. However, it is quite a remarkable text. I’m fascinated by the fact that it is told long after Socrates is dead. It is told when the young man that Socrates was engaging in this dialogue with is lying dying years later. It is told by two men who are both mathematicians. Mathematics was the most ‘developed’ science of the day and the one that is still closest to ‘the truth’. If anyone should know what ‘truth’ is then surely a mathematician is our best bet.

This doesn’t prove to be the case here. The question what is knowledge remains quite intractable. But what is gobsmackingly interesting here is the fact that we are so far removed from the date that the dialogue was supposed to have occurred and are being told this story through many whispers. This is a play written by Plato from a reading by a Slave of a text written by a friend of Socrates’s just before Socrates died. And then Plato starts asking what is true knowledge and how does memory impact on the reliability of knowledge and it is quite clear someone (perhaps someone nicknamed Plato – or Broad in English due, some speculate, because he had a fat head) is having a rather subtle go at us all.

Like I said, rather hard work – but then epistemology hasn’t gotten too much easier with the aeons.

[Gary · Rating 3 out of 5]

I can appreciate the genius of Plato but I disagree with the belief that all things can be reasoned out without the use of empirical knowledge. Rationalism is flawed in a way because (most) humans have poor memories, many of our ideas are warped by our biases, therefore our pre-sense reasoning can only go as far as the quality of our memory.

[Paul Haspel · Rating 5 out of 5]

Theaetetus, in real life, was a mathematician in ancient Athens – a student of Theodorus of Cyrene. Mathematics and philosophy were closely intertwined in those days, and mathematicians loved talking philosophy. It is fitting then, that both Theaetetus and Theodorus are interlocutors of Socrates in Plato’s dialogue Theaetetus, a dialogue that interrogates the nature of knowledge itself.

The dialogue begins on a sad note, with a framing dialogue in which Euclid of Megara (a philosopher, not the mathematician who wrote the Elements) discusses with the Socratic student Terpsion how Theaetetus has returned home to Athens, wounded and gravely ill with dysentery, after serving with the Athenian forces in war against Corinth. Euclid recalls how “I remembered with astonishment how Socrates had predicted Theaetetus’ future particularly accurately. It was shortly before Socrates’ death, I think, that he met Theaetetus, who was just a boy then…and was very favourably impressed with his natural abilities” (p. 15)

It is a sad note to start on, as the reader of this dialogue would have known of the premature deaths of both of the major participants in this dialogue – Socrates, executed by the Athenian authorities in 399 B.C. after a politically motivated and unfair trial, and Theaetetus, dead before his time from battle wounds and disease. Indeed, the dialogue repeatedly makes reference to the way that Theaetetus, with his snub nose and unprepossessing appearance, looks rather like a young Socrates, further emphasizing the parallels between these two Greek philosophers who are both moving toward an untimely death.

As always, Socrates uses his question-and-answer approach – what subsequent generations came to call the “Socratic method” – to point out inconsistencies in the thinking of others. By the time of the Theaetetus, Socrates’ reputation for this sort of thing is well-known: Theodorus says at one point, “Giving Socrates the opportunity for discussion is like giving cavalry the opportunity to fight on level ground” (p. 85). But both Theodorus and Theaetetus go along good-naturedly with the opportunity to pursue the issues being discussed in the dialogue.

Plato, as is his habit, places emphasis on a World of Forms that is better and purer than this imperfect material world. Socrates says, “The elimination of evil is impossible, Theodorus: there must always be some force ranged against good. But it is equally impossible for evil to be stationed in heaven: its territory is necessarily mortal nature – it patrols this earthly realm. That is why one should try to escape as quickly as possible from here to there” (pp. 72-73).

Yet the main thrust of the Theaetetus is epistemological. The dialogue constitutes an attempt to understand the nature of knowledge; Socrates states early in the conversation that “[W]e could see whether or not knowledge and perception are identical” (p. 50). Over the course of the dialogue, Theaetetus and Theodorus propose three distinct definitions of knowledge:

1. Knowledge is perception alone, pure and simple.
2. Knowledge is true judgement.
3. Knowledge is true judgement, supported by “an account” or some sort of evidence.

Socrates, unsurprisingly, finds that his answer to the question is 4. None of the above.

The first of these attempts to define knowledge presents problems that will be apparent to any undergraduate college student who has ever seen a friend across the quad, called out to the friend, and only then discovered that the person - in spite of resembling the friend in any number of particulars - is not in fact that friend at all. The Protagorean idea that knowledge is sense-perception alone falls apart rather quickly. Just ask that embarrassed undergraduate!

Dealing with Theodorus’ and Theaetetus’ second attempt to define knowledge – “Knowledge is true judgement” – takes a bit more doing. After all, we all try to judge justly, and we all like to think that, in some measure, we possess true judgement. But Socrates reminds Theaetetus how Athenian lawyers “use their expertise to persuade and make others believe whatever they want them to believe” and adds that when a jury renders a decision based on hearsay, “they do so without knowledge, but get hold of true belief” (p. 115). Socrates may be fudging things a bit, going back and forth between terms like “judgement” and “belief” so casually; but his point remains: a jury can render a demonstrably unjust verdict that its members truly believe is just - as with the unjust trial and unfair verdict that Socrates himself will soon face.

Socrates’ attempt to contravene the third attempt at a definition of knowledge – “Knowledge is true judgement, based on an account” – is likely to be most problematic for contemporary readers of the Theaetetus. If “account” here refers to an item of evidence that serves as the basis of a judgement, many modern readers may be unpersuaded by Socrates’ dwelling on the difficulty of forming precise definitions, as when the philosopher states that “[I]f you get hold of what uniquely differentiates something from everything else, you will arguably get a rational account of just that thing; but if the feature you get hold of is shared, your account will be concerned with however many things share this feature” (p. 127).

Ingeniously phrased, but problematic, for a couple of reasons. In the first place, there is a whole world of working definitions that are sufficiently precise for the activities of organized society to go forward; and in the second place, most people who live outside the rarefied world of pure philosophy have to use the evidence before them to make the best judgements they can, in order to carry on with their lives. Perhaps there is a good reason why this dialogue ends abruptly, and in a rather truncated manner.

The Theaetetus ends with Socrates stating that “now I have an appointment at the King’s Porch, to face the indictment which Meletus has brought against me. But let’s meet again here tomorrow morning, Theaetetus” (p. 131). This conclusion leads directly toward another of the late dialogues, the Sophist, with the same participants continuing to discuss these questions of what constitutes true knowledge. At the same time, it provides a sad reminder that the great Socrates is, as of the time of the dialogue, not long for this world.

This edition of Plato’s Theaetetus is followed by an explanatory essay – a long one: 114 pages of essay to accompany a 116-page dialogue. Robin A.H. Waterfield, who has done extensive translation and editing work for Penguin Books, seeks to understand what might lead many otherwise intelligent people to accept the intellectual shortcuts offered by Theodorus and Theaetetus:

“[I]f what I perceive conflicts with what you perceive, what are we to do? There are often no external, objective criteria which might allow one of us to claim that the other is wrong. So it is often sheer stubbornness or arrogance to claim that I am right and you are wrong, and few of us take this course: if we want to avoid scepticism and withholding judgement…altogether, we prefer to adopt the relativist position that both perceivers are correct, in their own ways.” (p. 148)

We live in a time when many people, on both sides of the political aisle, prefer to adopt an ideologically inflected view of reality itself. If they encounter factual data that contradict their political point of view, they cry out “fake news” and retreat to friendly media or social-media outlets that will tell them what they want to hear. Against that troubling contemporary backdrop, the search for true knowledge that is at the heart of the Theaetetus becomes more important than ever.

[Anastasija · Rating 3 out of 5]

Another classic philosophical dialogue by Plato, this time between Socrates and two young men, Theaetetus and Theodorus, discussing lively about what knowledge is. Plato’s dialogues are known for their wit, depth, and ability to challenge your thinking. So, this dialogue is no exception.

[Thomas · Rating 5 out of 5]

Theaetetus is an elaboration of the basic problem presented in Meno: how can we know something if we don't already know what that thing is? Doesn't something have to precede knowledge to tell us that what we "know" is true? The question that Theaetetus presents is similar to the "zetetic paradox" presented in Meno, but it is more specific and more compounded. Rather than the general question of how we know anything, it asks how do we know knowledge itself. After successfully dethroning relativity and the Protagorean answer that knowledge is perception and the truth of perception is relative, Socrates succeeds only in delivering a "wind egg" of the pregnant Theaetetus. We do not know what knowledge is, only what it is not. But what is it not turns out to be something after all.

Joe Sachs's translation is next best in accuracy to Benardete's, but it has the advantage of being readable. Sachs is very concerned with the Greek term dunamis in this dialogue and ends up translating "potency" and "power" where "ability" and "able" might be more natural alternatives, but aside from that the translation flows pretty well. The introduction is good and the footnotes are excellent, as usual.

[Amy · Rating 3 out of 5]

So far, this is the dialogue I enjoyed the least. The focus is ‘What is Knowledge?’ and supposedly this is one of the great foundations of epistemology, but I found the majority of this dialogue redundant and the arguments circular (or using the opposite/binary technique Socrates relies on so heavily) and I didn’t find it convincing. Better luck next dialogue.

[Cristian Kraemer · Rating 3 out of 5]

Os caras tentam definir o que é conhecimento

Spoiler: eles não conseguem

[Caroline · Rating 3 out of 5]

I don’t think I’d actually read any of Plato’s dialogues before, and I was expecting something different based on colloquial use of the term “Socratic method”. I had always pictured the student developing their own ideas while Socrates suggests other angles or brings up objections the student hasn’t thought of. Instead, Theaetetus hardly contributed anything to the dialogue beyond, “True,” “It seems that way to me,” and “Very much so, Socrates.” He just agreed with whatever Socrates said the entire time! Socrates claimed at several points that he didn’t have any ideas of his own, but just helped others evaluate their ideas. But I literally never saw Theaetetus suggest an idea!

I found this commentary quite helpful in understanding what was going on throughout the dialogue: https://plato.stanford.edu/archives/w... For example, Plato/Socrates didn’t really seem to distinguish between knowledge of a fact (e.g. knowing that Athens is the capital of Greece) vs. knowledge of a person (e.g. knowing Socrates). These have seemed obviously distinct to me since I learned Spanish, where these two types of “knowledge” are actually different words. Since then, it’s felt like a coincidence that we use the same word for both in English. While reading, I often wondered whether they are the same word in Greek, and if so whether the translator could have made the distinction more clear. I learned from the commentary that not only are they the same word in Greek, but one idiomatic way of saying, e.g. “I know [that] Socrates [is] wise” would actually be equivalent to saying, “I know [the] wise Socrates.” Apparently some people think Plato didn’t realize the difference between the two types of knowledge, while others think he did but saw them as related enough that it made sense to look for one definition encompassing both. Either way, knowing that made a lot of Socrates’ examples much easier to follow.

I started out reading the Jowett translation because it was free online, but then decided to buy the Sachs translation instead. I found Sachs easier to follow most of the time, and it was still confusing enough! For example, Theaetetus initially “defines” knowledge by listing several types of knowledge: geometry, leather cutting, etc. In the Sachs translation, Socrates responds, “But what was asked, Theaetetus, was not that, what things knowledge is about, or how many pieces of knowledge there are; for we didn’t ask it because we wanted to count them, but in order to discern knowledge itself—whatever that is. Or is there nothing in what I’m saying?” In the Jowett translation, this is, “But that, Theaetetus, was not the point of my question: we wanted to know not the subjects, nor yet the number of the arts or sciences, for we were not going to count them, but we wanted to know the nature of knowledge in the abstract. Am I not right?” Clearly they are saying the same thing, but I find Sach’s version much more clear. My main complaint with the Sachs translation was that the Greek “logos” was translated as “articulation” - so the final proposed definition of knowledge was “true opinion with an articulation”. This was somewhat salvaged by a translator’s note explaining different ways “logos” is used and giving alternate translations, such as “rational account”. However, the bizarre word choice “articulation” made the entire last section much more mental effort to follow. Jowett instead translated the last definition as “true opinion, combined with definition or rational explanation” which I much preferred.

I’m not sure how to rate this book. I read it because it is such a well known work, and I don’t regret reading it for that reason. I don’t think I got any new insights into knowledge from it, though. If it weren’t famous I wouldn’t have found it worth reading for its own sake.

[Juliette · Rating 3 out of 5]

« Car mieux vaut embrasser peu, mais bien, que beaucoup, sans y arriver »
J’ai décidé de lire tous les dialogues de Platon comme des manuels de drague

Plus sérieusement : de très beaux passages sur ce que c’est que penser et sur la mémoire, mais sinon ce n’est pas mon préféré… comme Théétète je commençais à fatiguer un peu à la fin (beaucoup de longs monologues de Socrate, j’adore pas)

Sinon je me suis en voie de devenir FK : mon marque page était une carte postale. Prochaine étape : la pléiade

Note pour la prochaine fois : ne pas abandonner le dialogue pendant 3 jours c’est super difficile de se remettre dedans après

[Mason]

Socrates lowkey be corrupting the youth in this one

[Jacob Aitken · Rating 5 out of 5]

Plato returns to his criticism of Protagoras’s claim that man is the measure of all things. Granted that such an argument is wrong (and silly), we explore the nature of knowledge and why it can’t be sense impression.

Theaetetus has just come back from the Sophists who argue that knowledge = sense perception. The larger context is Protagoras’s claim that “man is the measure of all things.” We will call this claim (P). We will distinguish this from Theaetetus’s claim that knowledge is perception, called (T).

Socrates asks him that if (T) is true, then knowledge must also be perceiving, to which Theaetetus agrees. If this is true, then a thing’s appearing-to-me must also be a thing’s being or existence. Our claim now entails that such knowledge is unerring (since it is connected with being). This, however, is manifestly false. Case in point: we perceive things in dreams, but no one thinks dreams are real.

Theaetetus retreats from this claim and attacks from the Heraclitean point of view that “motion is the source of being.” Flux, not stability is primary. There is no self-existent thing. Everything is becoming and in relation. He has the nice phrase “Partisans of the perpetual flux.” Indeed, we can’t even say man or stone, but only an aggregate of x. This is word-for-word Karl Marx (Marx, Theses on Feuerbach, Thesis VI).

Let’s return to (P). If it is true, then there is no reason to believe that Protagoras (or the modern university professor) is correct. If knowledge is sensation, and I can’t discern another man’s sensation, and yet Protagoras purports to be true, then why prefer him to anyone else? This was the first response to postmodernism long before postmodernism came on the scene.

Another problem: I can have knowledge from memory, yet memory isn’t a sense.
Another problem: I can have knowledge of abstract entities and categories, yet these are present to the senses.

Let’s return to the Heraclitean claim. If nothing is at rest, and everything is supervening upon everything else, then every answer is equally right, since all we have are moving targets.

There is yet another diversion where Socrates explains that the soul perceives some things by herself and others by means of bodily organs. The soul has something like “wax” in it that handles the impressions. If a soul is deep and virtuous, then the impressions sink to the heart of the soul.

The dialogue ends with discussions of justified, true belief.

Arguably the most important of his “epistemology” dialogues, it is somewhat a difficult read as Socrates goes through numerous diversions.

[Anmol · Rating 4 out of 5]

Now this is just where my difficulty comes in. I can’t get a proper grasp of what on earth knowledge really is.

I found this to be a very interesting read in parts, almost up there with the 4 early dialogues comprising the trial and death of Socrates in terms of readability. I love how Socrates coaxes his interlocutors into the discussion by feigning ignorance and hiding behind a neutral curiosity. He considers himself a metaphorical midwife, though I believe this metaphor is ripe for a feminist critique -

Now my art of midwifery is just like theirs in most respects. The difference is that I attend men and not women, and that I watch over the labor of their souls, not of their bodies.

This impliedly equates man with soul, woman with body, and all the connotations that follow from that for the spiritual and the sensual. Here, we see a Socrates different from that of the Republic, at least in this manner.

One must commend Plato for shaping this dialogue in a manner that deceives the reader at every turn. For example, whenever I would think of a possible fault with what is being written, Socrates would immediately work on that very fault at the next step. I understand why his interlocutors always considered him so thorough and painstaking.

My most important takeaway from this dialogue is that an inquiry into epistemology introduces humility in us. When we question what knowledge is, and consequently, if we ever have it, we realise that a lot of what we say isn't really something that we know. If I may say so, I believe (and not know :p) that this is also what Socrates intends in this dialogue. 2 passages contribute to my belief -

If we continue like this, one of two things will happen. Either we shall find what we are going out after; or we shall be less inclined to think we know things which we don’t know at all—and even that would be a reward we could not fairly be dissatisfied with.

...you will be modest and not think you know what you don’t know. This is all my art can achieve—nothing more.

This highlights the potential of philosophy: even if it cannot bestow us with "true" knowledge, it can cause a mindful shift in our habits, making us more conscious of what our words really mean before we say them.

[jude · Rating 5 out of 5]

what is knowledge!!! what is knowing!!!! what does it mean to know!!!! nobody knows anything!!!!! knowledge might be unattainable!!!!!!! aaaaaaa!!!!!

now that that's out of the way, well — what is there to say? my professors have all said that the whole of philosophy is nothing but a footnote to plato, and no offence but i genuinely cannot believe how true this is up to the present day.

perhaps even more timely with the present post-truth society wherein the borders of 'knowing' and 'thinking' and 'feeling' are all being blurred together like some impressionist painting, i think that more people ought to read this book so that they might think more deeply about their own beliefs and prior conceptions of the world.

in the end, i finish this review with just about the highest word of praise i can muster for this book —

some two and a half millennia on, we're still asking ourselves the same question posed in this book: what is knowledge, really?

(& do you know?)

[Matthieu · Rating 4 out of 5]

Next to Parmenides, this is probably the most rigourous/'difficult' Platonic dialogue. It might also be the most frustrating, mainly due to the fact that the intellectual bandying-about does not yield any clear, definitive conclusion. The dialogue asks: What is knowledge?, Is knowledge perception? (T.'s response), and, Can one have knowledge of knowledge? In a forest of ideas and assertions (along with some brilliant metaphors on the part of Socrates (midwifery)), no answer is to be found.

This is certainly not the ideal entry point into all things Plato; for the newcomer, I'd recommend Meno or Gorgias as they contain similar themes, but aren't quite so abstract and demanding. However, for one familiar with the ideas contained therein, the denseness is strangely purifying.

[Richard Newton · Rating 5 out of 5]

This is a great translation of one of Plato's most complex and interesting books. This is never going to be the easiest of reads, but the translator makes a great attempt to make it accessible, and bar one or two areas which require really close attention this is a fairly straightforward read. He has an extensive essay at the end of the book, which is helpful, but not perfect.

[Sebastián Briceño · Rating 5 out of 5]

Uno de mis diálogos platónicos favoritos. Es harto más que una discusión sobre lo que es conocimiento. Se abordan otras cuestiones particularmente interesantes: los rasgos distintivos del filósofo; la relación entre todo y partes; las formas en que algo puede ser explicado. Me fascina esta edición porque las notas de McDowell son un tesoro.

[evaporée · Rating 3 out of 5]

ambiance they don't know that we know they know we know… ct bien chiant parfois et je sais tjr pas ce que c’est la science (le plot est gâché par la fin, tout ce suspense pour ça… bien que j’aie adoré discuter de l’importance de la nuance de l’aplatissement du nez), mais ct chouette en v2v ça m’a un peu réconciliée avec platon me voilà dans mon redemption arc je commence à comprendre la hype

[Karl Hallbjörnsson · Rating 3 out of 5]

the dialogues are remarkable not for their philosophical content but for the form of the discourse itself

[Airam · Rating 4 out of 5]

If you're still looking for answers in philosophy, boy are you barking at the wrong tree.

[Luciana · Rating 4 out of 5]

só os grávidos

[Burak leest · Rating 5 out of 5]

Indrukwekkende dialoog van Platon over kennis, waarneming en het zijn van dingen.