The difficulty in framing general notions which has appeared in this and
in all the previous Dialogues recurs in the Gorgias and Theaetetus as
well as in the Republic. In the Gorgias too the statesmen reappear, but
in stronger opposition to the philosopher. They are no longer allowed to
have a divine insight, but, though acknowledged to have been clever men
and good speakers, are denounced as 'blind leaders of the blind.' The
doctrine of the immortality of the soul is also carried further, being
made the foundation not only of a theory of knowledge, but of a doctrine
of rewards and punishments. In the Republic the relation of knowledge
to virtue is described in a manner more consistent with modern
distinctions. The existence of the virtues without the possession
of knowledge in the higher or philosophical sense is admitted to be
possible. Right opinion is again introduced in the Theaetetus as
an account of knowledge, but is rejected on the ground that it is
irrational (as here, because it is not bound by the tie of the cause),
and also because the conception of false opinion is given up as
hopeless. The doctrines of Plato are necessarily different at different
times of his life, as new distinctions are realized, or new stages of
thought attained by him. We are not therefore justified, in order to
take away the appearance of inconsistency, in attributing to him hidden
meanings or remote allusions.
There are no external criteria by which we can determine the date of the
Meno. There is no reason to suppose that any of the Dialogues of Plato
were written before the death of Socrates; the Meno, which appears to be
one of the earliest of them, is proved to have been of a later date by
the allusion of Anytus.
We cannot argue that Plato was more likely to have written, as he has
done, of Meno before than after his miserable death; for we have already
seen, in the examples of Charmides and Critias, that the characters in
Plato are very far from resembling the same characters in history. The
repulsive picture which is given of him in the Anabasis of Xenophon,
where he also appears as the friend of Aristippus 'and a fair youth
having lovers,' has no other trait of likeness to the Meno of Plato.