All the interests and contrasts of character in a great dramatic work like
the Protagoras are not easily exhausted. The impressiveness of the scene
should not be lost upon us, or the gradual substitution of Socrates in the
second part for Protagoras in the first. The characters to whom we are
introduced at the beginning of the Dialogue all play a part more or less
conspicuous towards the end. There is Alcibiades, who is compelled by the
necessity of his nature to be a partisan, lending effectual aid to
Socrates; there is Critias assuming the tone of impartiality; Callias, here
as always inclining to the Sophists, but eager for any intellectual repast;
Prodicus, who finds an opportunity for displaying his distinctions of
language, which are valueless and pedantic, because they are not based on
dialectic; Hippias, who has previously exhibited his superficial knowledge
of natural philosophy, to which, as in both the Dialogues called by his
name, he now adds the profession of an interpreter of the Poets. The two
latter personages have been already damaged by the mock heroic description
of them in the introduction. It may be remarked that Protagoras is
consistently presented to us throughout as the teacher of moral and
political virtue; there is no allusion to the theories of sensation which
are attributed to him in the Theaetetus and elsewhere, or to his denial of
the existence of the gods in a well-known fragment ascribed to him; he is
the religious rather than the irreligious teacher in this Dialogue. Also
it may be observed that Socrates shows him as much respect as is consistent
with his own ironical character; he admits that the dialectic which has
overthrown Protagoras has carried himself round to a conclusion opposed to
his first thesis. The force of argument, therefore, and not Socrates or
Protagoras, has won the day.

But is Socrates serious in maintaining (1) that virtue cannot be taught;
(2) that the virtues are one; (3) that virtue is the knowledge of pleasures