The course of this dialogue--the Theætêtus--has been already described as an assemblage of successive perplexities without any solution. But what deserves farther notice is--That the perplexities, as they are not solved in this dialogue, so they are not solved in any other dialogue. The view taken by Schleiermacher and other critics--that Plato lays out the difficulties in one anterior dialogue, in order to furnish the solution in another posterior--is not borne out by the facts. In the Theætêtus, many objections are propounded against the doctrine, That Opinion is sometimes true, sometimes false. Sokrates shows that false opinion is an impossibility: either therefore all opinions are true, or no opinion is either true or false. If we turn to the Sophistês, we shall find this same question discussed by the Eleatic Stranger who conducts the debate. He there treats the doctrine--That false opinion is an impossibility and that no opinion could be false--as one which had long embarrassed himself, and which formed the favourite subterfuge of the impostors whom he calls Sophists. He then states that this doctrine of the Sophists was founded on the Parmenidean dictum--That Non-Ens was an impossible supposition. Refuting the dictum of Parmenides (by a course of reasoning which I shall examine elsewhere), he arrives at the conclusion--That Non-Ens exists in a certain fashion, as well as Ens: That false opinions are possible: That there may be false opinions as well as true. But what deserves most notice here, in illustration of Plato's manner, is--that though the Sophistês[142] is announced as a continuation of the Theætêtus (carried on by the same speakers, with the addition of the Eleate), yet the objections taken by Sokrates in the Theætêtus against the possibility of false opinion, are not even noticed in the Sophistês--much less removed. Other objections to it are propounded and dealt with: but not those objections which had arrested the march of Sokrates in the Theætêtus.[143] Sokrates and Theætêtus hear the Eleatic Stranger discussing this same matter in the Sophistês, yet neither of them allude to those objections against his conclusion which had appeared to both of them irresistible in the preceding dialogue known as Theætêtus. Nor are the objections refuted in any other of the Platonic dialogues. [Footnote 142: See the end of the Theætêtus and the opening of the Sophistês. Note, moreover, that the Politikus makes reference not only to the Sophistês, but also to the Theætêtus (pp. 258 A, 266 D, 284 B, 286 B).]