Protagoras

Plato already had the strongest incentive in the Apology to oppose the confusion of Socrates with the Sophists (19 ff). Now, however, it was necessary to secure his own activity, which, after all, intended to directly continue that of Socrates, on the same side. And given the continuously embittered mood against the "masters of cultivation" and "peddlers of cultivation"—this contemptuous secondary meaning, which the word "Sophist" (which in itself only denotes the professional class) has received precisely from this zeitgeist, e.g., Prot. 313 CD—this had to be his first concern, if he wanted to make possible for himself an activity in Athens at all, even if not immediately after the death of Socrates (as is still his intention in the Apology, 39 C), yet, as we may assume, only a short time after.

But above all, from a purely objective point of view, a successor of Socrates had to recognize a difficult problem in the teachability of virtue. Socrates had asserted that virtue is knowledge; therefore, it should, of course, also be teachable. However, the same Socrates had, according to the unambiguous testimony of Plato in the Apology, definitely denied its teachability. Not only do the Sophists and Socrates himself not possess the science of human education, but it goes, according to his blunt and clear explanation, beyond human wit altogether (Apol. 19 D, 20 D). In full agreement with this, Socrates declares in the Protagoras (319 ff): until then—i.e., before the instruction he had just received through Protagoras—he had not believed that virtue was teachable or could be imparted to humans by humans; or (328 E) that it is not human effort through which the excellent become excellent. In contrast, the head of the Sophists, Protagoras, in agreement with his colleagues and under the thunderous applause of the listeners, defends the thesis of teachability, and indeed from no other outlook than the one that the accuser of Socrates, Meletus, defends quite naively (Apol. 24 D—26 A): everyone helps with the teaching of virtue, the laws, the judges, the entire people; only for that reason does no single person want to be cited as an expert for it, because all are (in contrast to the one expert: Crito 47 BD, 48 A, Prot. 314 A, and elsewhere). And again in the Meno, Plato explains, visibly in defense of what he maintained in the Protagoras: Socrates (namely in the Protagoras) by no means wanted to attach an insult to Pericles and the other state leaders, but only wanted to prove by their example that virtue is not teachable at all, that it is not something