Plato's Theaetetus, on Knowledge

The Theaetetus is Plato's dialogue concerning knowledge, although it is beautifully woven with many rich themes and images.

Is knowledge perception? true judgment? true judgment with an account? Each of these definitions is shown to be unsatisfactory.

Along the way we witness Socrates' engagement with the philosophy of Heraclitus and Protagoras, both whom we've recently discussed in this group.

This exciting dialogue is a favorite to many, so read in advance and let's discuss together.

 

TEXT AVAILABLE ONLINE. Project Gutenberg

 

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  • Rick O.

    Okay, I think I've officially lost it. Ever since last Sat meetup everything I read sounds like Heidegger. Socrates, in s160a-c, sounds like he is elaborating the For structure from B&T. Fortunately, though, I kinda like Heidegger, so I think I'll just go with the flow.

    2 · August 24, 2013

    • Thrashionalist

      That it follows so beautifully from Thursday's Leibniz meetup provides further proof (if more were needed) of pre-established harmony.

      1 · August 24, 2013

  • Mike B.

    A small point: At 176b, I read "a man becomes like God when he becomes just and pure." I suspect that the word pure, even today, cannot escape meaning something like sexual abstinence or inexperience. Can anyone comment on the concept associated with what English translators rend as "pure"?

    August 24, 2013

    • Brian

      I tend to associate pure with bright happy consciousness.

      August 24, 2013

  • Mike B.

    Brian, I can't quite follow your comment on the sophists' denial of being mistaken.

    August 24, 2013

  • Thrashionalist

    I'm deeply interested in the question, introduced toward the end of the dialogue, of how error is possible. How can I believe what-is-not? How can I say something-that-is-not? I always believe something (extant), and I always say something (extant).

    We can acknowledge that error occurs - that the concept has application. But what is the best model for what's going on when we say that an error has been made? I tend to think that a correspondence picture, where error is something that fails to match reality, is useful on a casual level but incoherent on analysis. (It presumes access to reality independent of the access we have to reality.)

    August 23, 2013

    • Joel N.

      I think it's a matter of choosing one belief over another. There is the original perception and the belief we formed based on it. Later, there is the introduction of new evidence, resulting in new perceptions and beliefs. Either we continue to hold to the correctness of the original belief about the perception, or we state that that belief was incorrect and the new belief better describes things.

      August 23, 2013

    • Joel N.

      I wish I could be there to highlight Plato's logical shenanigans, but alas, I'm busy. I hope at least one member of the group defends some variation of Protagoras' view.

      August 23, 2013

  • Mike B.

    Brian, Burnyeat considers thraetetus a 16-year-old student.

    August 22, 2013

    • Brian

      yeah, student of Theodorus. I think we are meant to see him as 'mathematician'­ since the interlocutor's teacher is often included by Plato as a clue to understanding the action of a dialogue. In most dialogues the teacher is a sophist. But here it is a mathematician. As we know, math is the icon of good education for Plato. That Theaetetus is the younger mathematician and yet the more impressive philosopher (compared to his teacher) I think signals travelling the bridge from the lower to higher intelligible region of The Divided Line (Republic)( sorry to dump ideas, we can discuss tmw)

      August 23, 2013

  • Mike B.

    I am using Burnyeat's edition (Hackett, 1990), where at 145d, I find "to learn is to become wiser" with the following note added: "the words 'wise' and 'wisdom' in the argument. . . . The point of the argument will come across more naturally in English if readers substitute . . . 'Expert' and 'expertise'." I am Greekless. Does any have an opinion on altering the text for such a reason. I always wondered if 'Sophia' might refer to an excellence of mind that was more than merely intellectual.

    August 22, 2013

  • Mike B.

    At 164d (and elsewhere earlier) Socrates mentions Prtagoras, while apparently assuming that "man is the measure" is equivalent to the notion that "perception equals knowledge." My question: Do these two propositions necessarily entail one another?
    I find the Socrates of the early dialogues congenial. In Theaetetus, however, Socrates comes across as the assured teacher confident in his own knowledge. At times I feel he is lecturing (e.g., at 153), and at other times just playing with words (by "playing with words" I mean to suggest that his argument has little philosophic weight).
    This last question suggests to me that the persona of Socrates in each of the dialogues does embody philosophic content.

    August 22, 2013

    • Brian

      hmm. The two sentences can be blended together: each man's (judgment of his) perception is the measure of knowledge of things.

      August 22, 2013

  • Brian

    Theaetetus is a mathematician. I think we can understand this dialogue with reference to the divided line in the republic, moving from senses to hypothesis, to something truly grounded

    August 19, 2013

    • Erik C.

      Isn't Euclides the mathematician, and Theaetetus his student?

      August 20, 2013

    • Brian

      Theodorus is the mathematician. Theaetetus is the student, but I think he gets to be called a mathematician too since it explains why he's such a good interlocutor compared to Meno/Callicles who sucked at math. For example, Theaetetus figures out what a definition should look like and doesn't stick on particulars. Nor does he spend lots of time disagreeing with himself

      1 · August 20, 2013

  • Mike B.

    Erik, theaetetus is a student of Theodorus.

    August 20, 2013

  • Mike B.

    Let me challenge everybody's ingenuity: what can be made of the slave who reads Eucleides' notes? We seem to have a lot of factors here, beginning with Plato's thoughts on texts versus oral exchange and which easily confuses me. Why? Well, to begin we might think that knowledge should be something stable and un changing. Yet a text for Plato is flawed precisely because it says the same thing over and over again.

    August 20, 2013

    • Erik C.

      The owner of the slave also makes a comment about the accuracy of his text. About how he wrote it down, then checked the story against Socrates' account whenever he had a question. I think that this is potentially significant for the whole dialogue.

      August 20, 2013

  • Adam

    Knowledge, eh?

    July 7, 2013

    • Brian

      That MIGHT be helpful???

      August 16, 2013

    • Brian

      No consensus on justification. Because to give a proper logos, presupposes we know what knowledge is. But this is precisely the object of our inquiry to discover.

      August 19, 2013

  • Mary

    :)

    1 · July 7, 2013

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