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. [Sidenote: _Date of the Dialogue._] 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 (94 E, 95 A. Cp. also 80 B, 100 B). 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 (ii. 6), 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.