e. The assent of
Protagoras to this last position is extracted with great difficulty.

Socrates concludes by professing his disinterested love of the truth,
and remarks on the singular manner in which he and his adversary had
changed sides. Protagoras began by asserting, and Socrates by denying,
the teachableness of virtue, and now the latter ends by affirming that
virtue is knowledge, which is the most teachable of all things, while
Protagoras has been striving to show that virtue is not knowledge, and
this is almost equivalent to saying that virtue cannot be taught. He is
not satisfied with the result, and would like to renew the enquiry with
the help of Protagoras in a different order, asking (1) What virtue is,
and (2) Whether virtue can be taught. Protagoras declines this offer,
but commends Socrates' earnestness and his style of discussion.

The Protagoras is often supposed to be full of difficulties. These
are partly imaginary and partly real. The imaginary ones are (1)
Chronological,--which were pointed out in ancient times by Athenaeus,
and are noticed by Schleiermacher and others, and relate to the
impossibility of all the persons in the Dialogue meeting at any one
time, whether in the year 425 B.C., or in any other. But Plato, like
all writers of fiction, aims only at the probable, and shows in many
Dialogues (e.g. the Symposium and Republic, and already in the Laches)
an extreme disregard of the historical accuracy which is sometimes
demanded of him. (2) The exact place of the Protagoras among the
Dialogues, and the date of composition, have also been much disputed.
But there are no criteria which afford any real grounds for determining
the date of composition; and the affinities of the Dialogues, when they
are not indicated by Plato himself, must always to a great extent remain
uncertain. (3) There is another class of difficulties, which may be
ascribed to preconceived notions of commentators, who imagine that
Protagoras the Sophist ought always to be in the wrong, and his
adversary Socrates in the right; or that in this or that passage--e.g.
in the explanation of good as pleasure--Plato is inconsistent with
himself; or that the Dialogue fails in unity, and has not a proper
beginning, middle, and ending. They seem to forget that Plato is a
dramatic writer who throws his thoughts into both sides of the argument,
and certainly does not aim at any unity which is inconsistent with
freedom, and with a natural o