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Theaetetus

§151

Theaetetus' Definition of Knowledge as Perception

Socrates explains his role as a midwife for intellectual labor, encouraging Theaetetus to define knowledge without fear. In response, Theaetetus proposes his first definition, stating that knowledge is nothing but perception.

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§151

ΣΩ. ὧν εἷς γέγονεν Ἀριστείδης ὁ Λυσιμάχου καὶ ἄλλοι πάνυ πολλοί· οὕς, ὅταν πάλιν ἔλθωσι δεόμενοι τῆς ἐμῆς συνουσίας καὶ θαυμαστὰ δρῶντες, ἐνίοις μὲν τὸ γιγνόμενόν μοι δαιμόνιον ἀποκωλύει συνεῖναι,1 ἐνίοις δὲ ἐᾷ, καὶ πάλιν οὗτοι ἐπιδιδόασι. πάσχουσι δὲ δὴ οἱ ἐμοὶ συγγιγνόμενοι καὶ τοῦτο ταὐτὸν ταῖς τικτούσαις· ὠδίνουσι γὰρ καὶ ἀπορίας ἐμπίμπλανται νύκτας τε καὶ ἡμέρας πολὺ μᾶλλον ἢ ʼκεῖναι· ταύτην δὲ τὴν ὠδῖνα ἐγείρειν τε καὶ ἀποπαύειν ἡ ἐμὴ τέχνη δύναται. καὶ οὗτοι μὲν δὴ οὕτως. ἐνίοις δέ, ὦ Θεαίτητε, οἳ ἄν μοι μὴ δόξωσί πως ἐγκύμονες εἶναι, γνοὺς ὅτι οὐδὲν ἐμοῦ δέονται, πάνυ εὐμενῶς προμνῶμαι καί, σὺν θεῷ εἰπεῖν, πάνυ ἱκανῶς τοπάζω οἷς ἂν συγγενόμενοι ὄναιντο· ὧν πολλοὺς μὲν δὴ ἐξέδωκα προδίκῳ, πολλοὺς δὲ ἄλλοις σοφοῖς τε καὶ θεσπεσίοις ἀνδράσι. ταῦτα δή σοι, ὦ ἄριστε, ἕνεκα τοῦδε ἐμήκυνα· ὑποπτεύω σε, ὥσπερ καὶ αὐτὸς οἴει, ὠδίνειν τι κυοῦντα ἔνδον. προσφέρου οὖν πρός με ὡς πρὸς μαίας ὑὸν καὶ αὐτὸν μαιευτικόν, καὶ ἃ ἂν ἐρωτῶ προθυμοῦ ὅπως οἷός τʼ εἶ οὕτως ἀποκρίνασθαι· καὶ ἐὰν ἄρα σκοπούμενός τι ὧν ἂν λέγῃς ἡγήσωμαι εἴδωλον καὶ μὴ ἀληθές, εἶτα ὑπεξαιρῶμαι καὶ ἀποβάλλω, μὴ ἀγρίαινε ὥσπερ αἱ πρωτοτόκοι περὶ τὰ παιδία. πολλοὶ γὰρ ἤδη, ὦ θαυμάσιε, πρός με οὕτω διετέθησαν, ὥστε ἀτεχνῶς δάκνειν ἕτοιμοι εἶναι, ἐπειδάν τινα λῆρον αὐτῶν ἀφαιρῶμαι, καὶ οὐκ οἴονταί με εὐνοίᾳ τοῦτο ποιεῖν, πόρρω ὄντες τοῦ εἰδέναι ὅτι οὐδεὶς θεὸς δύσνους ἀνθρώποις, οὐδʼ ἐγὼ δυσνοίᾳ τοιοῦτον οὐδὲν δρῶ, ἀλλά μοι ψεῦδός τε συγχωρῆσαι καὶ ἀληθὲς ἀφανίσαι οὐδαμῶς θέμις. πάλιν δὴ οὖν ἐξ ἀρχῆς, ὦ Θεαίτητε, ὅτι ποτʼ ἐστὶν ἐπιστήμη, πειρῶ λέγειν· ὡς δʼ οὐχ οἷός τʼ εἶ, μηδέποτʼ εἴπῃς. ἐὰν γὰρ θεὸς ἐθέλῃ καὶ ἀνδρίζῃ, οἷός τʼ ἔσῃ. ΘΕΑΙ. ἀλλὰ μέντοι, ὦ Σώκρατες, σοῦ γε οὕτω παρακελευομένου αἰσχρὸν μὴ οὐ παντὶ τρόπῳ προθυμεῖσθαι2 ὅτι τις ἔχει λέγειν. δοκεῖ οὖν μοι ὁ ἐπιστάμενός τι αἰσθάνεσθαι τοῦτο ὃ ἐπίσταται,3 καὶ ὥς γε νυνὶ φαίνεται, οὐκ ἄλλο τί ἐστιν ἐπιστήμη ἢ αἴσθησις. ΣΩ. εὖ γε καὶ γενναίως, ὦ παῖ· χρὴ γὰρ οὕτως ἀποφαινόμενον λέγειν. ἀλλὰ φέρε δὴ αὐτὸ κοινῇ σκεψώμεθα, γόνιμον ἢ ἀνεμιαῖον τυγχάνει ὄν. αἴσθησις, φῄς, ἐπιστήμη; ΘΕΑΙ. ναί.

​SOCRATES: Of whom one is Aristides, the son of Lysimachus, and there are very many others. When they come back, begging for my company and doing extraordinary things, with some of them the divine sign that comes to me forbids me to associate, but with others it allows, and these again make progress. And those who associate with me experience this same thing as women in labor: they suffer labor pains and are filled with perplexity night and day far more than those women. But to arouse this labor pain and to soothe it, my art is able. And these indeed are so. But for some, Theaetetus, who do not seem to me to be at all pregnant, recognizing that they have no need of me, I very kindly match them, and, with god’s help, I guess very successfully with whom they would benefit by associating; many of them I have given over to Prodicus, and many to other wise and inspired men. I have lengthened this story for you, my excellent friend, for this reason: I suspect that you, as you yourself think, are in labor with something pregnant within you. Come, therefore, to me as to the son of a midwife who is himself a practitioner of the art, and strive to answer what I ask in whatever way you can. And if, when I examine something of what you say, I should consider it a phantom and not true, and then secretly take it away and cast it aside, do not be angry with me like women who are having their first child over their babies. For many, my wonderful boy, have been so disposed toward me that they were ready to bite me, when I took away some nonsense of theirs, and they do not think that I do this out of goodwill, being far from knowing that no god is ill-disposed to men, nor do I do any such thing out of ill-will, but it is by no means permitted for me to yield to falsehood and to suppress the truth. So, back again from the beginning, Theaetetus, try to say what knowledge is; and never say that you are not able. For if god wills and you act like a man, you will be able. THEAETETUS: But indeed, Socrates, when you encourage me in this way, it would be shameful not to strive in every way to say what one has in mind. It seems to me, then, that he who knows something perceives that which he knows, and as it appears at present, knowledge is nothing other than perception. SOCRATES: Well and nobly said, my boy; for one must speak out in this way when declaring his opinion. But come now, let us examine it together, to see whether it is a fertile offspring or a wind-egg. Perception, you say, is knowledge? THEAETETUS: Yes.

Syntax notes3 items
  1. 151ἐνίοις μὲν τὸ γιγνόμενόν μοι δαιμόνιον ἀποκωλύει συνεῖναι

    The subject is τὸ γιγνόμενόν μοι δαιμόνιον (the divine sign that comes to me). ἐνίοις (to some) functions as the dative complement of either the infinitive συνεῖναι (to associate with) or the main verb ἀποκωλύει.

  2. 151dαἰσχρὸν μὴ οὐ παντὶ τρόπῳ προθυμεῖσθαι

    Following the negative adjective αἰσχρόν (shameful), the double negative particle μὴ οὐ is used with the infinitive προθυμεῖσθαι to express a strong necessity ("it is shameful not to strive by all means").

  3. 151eὁ ἐπιστάμενός τι αἰσθάνεσθαι τοῦτο ὃ ἐπίσταται

    This is an infinitive construction dependent on δοκεῖ, where ὁ ἐπιστάμενός τι (he who knows something) acts as the subject of the infinitive αἰσθάνεσθαι.

Translated by Gemini 3.5 Flash (published 2026-05-22)urn:cts:greekLit:tlg0059.tlg006.humanitext-grc2:151