To do wrong, overcome by pleasure, is only a bad phrase for describing what is really a case of grave ignorance.
For when we (Protagoras and Sokrates) affirmed, that nothing was more powerful than science or knowledge, and that this, in whatsoever minds it existed, prevailed over pleasure and every thing else — you (the supposed objectors) maintained, on the contrary, that pleasure often prevailed over knowledge even in the instructed man: and you called upon us to explain, upon our principles, what that mental affection was, which people called, being overcome by the seduction of pleasure. We have now shown you that this mental affection is nothing else but ignorance, and the gravest ignorance. You have admitted that those who go wrong in the choice of pleasures and pains — that is, in the choice of good and evil things — go wrong from want of knowledge, of the knowledge or science of mensuration. The wrong deed done from want of knowledge, is done through ignorance. What you call being overcome by pleasure is thus, the gravest ignorance; which these Sophists, Protagoras, Prodikus, and Hippias, engage to cure: but you (the objectors whom we now address) not believing it to be ignorance, or perhaps unwilling to pay them their fees, refuse to visit them, and therefore go on doing ill, both privately and publicly.[116]
[116] Plato, Protag. p. 357 E.
Reasoning of Sokrates assented to by all. Actions which conduct to pleasures or freedom from pain, are honourable.
Now then, Protagoras, Prodikus, and Hippias (continues Sokrates), I turn to you, and ask, whether you account my reasoning true or false? (All of them pronounced it to be surpassingly true.) Sokr. — You all agree, then, all three, that the pleasurable is good, and that the painful is evil:[117] for I take no account at present of the verbal distinctions of Prodikus, discriminating between the pleasurable, the delightful, and the enjoyable. If this be so, are not all those actions, which conduct to a life of pleasure or to a life free from pain, honourable? and is not the honourable deed, good and profitable?[118] (In this, all persons present concurred.) If then the pleasurable is good, no one ever does anything, when he either knows or believes other things in his power to be better. To be inferior to yourself is nothing else than ignorance: to be superior to yourself, is nothing else than wisdom. Ignorance consists in holding false opinions, and in being deceived respecting matters of high importance. (Agreed by all.) Accordingly, no one willingly enters upon courses which are evil, or which he believes to be evil; nor is it in the nature of man to enter upon what he thinks evil courses, in preference to good. When a man is compelled to make choice between two evils, no one will take the greater when he might take the less.[119] (Agreed to by all three.) Farther, no one will affront things of which he is afraid, when other things are open to him, of which he is not afraid: for fear is an expectation of evil, so that what a man fears, he of course thinks to be an evil, — and will not approach it willingly. (Agreed.)[120]
[117] Plato, Protag. p. 358 A. ὑπερφυῶς ἐδόκει ἅπασιν ἀληθῆ εἶναι τὰ εἰρημένα. Ὁμολογεῖτε ἄρα, ἦν δ’ ἐγώ, τὸ μὲν ἡδὺ ἀγαθὸν εἶναι, τὸ δὲ ἀνιαρὸν κακόν.
[118] Plato, Protag. p. 358 B. αἱ ἐπὶ τούτου πράξεις ἅπασαι ἐπὶ τοῦ ἀλύπως ζῆν καὶ ἠδέως, ἆρ’ οὐ καλαί; καὶ τὸ καλὸν ἔργον, ἀγαθόν τε καὶ ὠφέλιμον;
[119] Plato, Protag. p. 358 C-D. ἐπί γε τὰ κακὰ οὐδεὶς ἑκὼν ἔρχεται, οὐδὲ ἐπὶ ἃ οἴεται κακὰ εἶναι, οὐδ’ ἐστὶ τοῦτο, ὡς ἔοικεν, ἐν ἀνθρώπου φύσει, ἐπὶ ἃ οἴεται κακὰ εἶναι ἐθέλειν ἰέναι ἀντὶ τῶν ἀγαθῶν· ὅταν τε ἀναγκάσθῃ δυοῖν κακοῖν τὸ ἕτερον αἰρεῖσθαι, οὐδεὶς τὸ μεῖζον αἱρήσεται, ἐξὸν τὸ ἔλαττον.
[120] Plato, Protag. p. 358 E.
Explanation of courage. It consists in a wise estimate of things terrible and not terrible.