fairly be started, how Plato could have made Gorgias the principal person in a dialogue without uttering a syllable about this work, or noticing it by a single allusion. Put the dialogue into the period at which the process against Socrates was still going on, and we then have a very easy justification, in the supposition that at that time Plato had not yet become acquainted with it; but this supposition will not hold after his return from his travels, as he must unquestionably have made acquaintance with this work in Sicily. In this case, there are but two hypotheses from which to choose: either Plato, contrary to his usual custom in this particular, has kept so accurately to the time in which he places the dialogue, that he does not mention this work because at that period it was not yet known at Athens, and this may certainly be conceived, if as Olympiodorus says, it was written in the eighty-fourth Olympiad ; or Plato did not consider this work deserving of particular notice, not so much by reason of its sophistical tendency, as, much more probably, its utterly rhetorical style; and thus he only comprehends it generally under the description of the corrupting art of counterfeit, and makes Gorgias say, probably not without a meaning, that he does not pretend to be anything but an orator.

II. THEÆTETUS.

IF the reader looks only to the difficulties which surround this dialogue considered in itself, and as it is usually understood, and to the sophistries of which it is accused by those who are uninitiated into the connection, he may perhaps wish for a fuller introduction to the understanding of it than he will here meet with. But much becomes at once clear from the place we assign to the Theætetus, and from immediate reference to what was said on the Gorgias. For when it is remembered what was there stated to be the common object of the two dialogues, and how the Gorgias is intended to pursue that object more on the practical side, the Theætetus more on the theoretical, the perplexity must at once become considerably less intricate, and some notion will be given of the real subject of the dialogue, in which, otherwise, at first sight, every thing seems to cancel the rest, and notwithstanding that knowledge is the subject of the argument, nothing apparently remains but ignorance; so that this hitherto sealed work will be explained at the same time that the correctness of that connection, and of the general view taken of the whole, receive additional confirmation. For according to that view, the main object of the Theætetus must be to show, that no science can be found unless we completely separate Truth and Being from the Perceived and Perceptible or Apparent. Only that in this dialogue, as the sciences generally were not so strictly separated and individually defined as the arts, Plato himself having been almost the first to attempt this, the dis

cussion does not here enter upon the whole system of the sciences, as in the Gorgias on that of the arts, but treats of their common element, or of knowledge in the strictest sense of the word. And not only this, but it was a principle of Plato, as well as his object to show, that both investigations are in their nature counterparts of one another, that the search for the good in pleasure, and that for pure knowledge in the sensuous perception, are grounded upon one and the same mode of thought, that, namely, which the Gorgias exhibits more at full. Therefore it is shown betimes, and no one will wonder how this subject came to be here introduced, what influence the doctrine tried must have upon the ideas of the good and beautiful, and upon the method of considering them

it is shown that in the mind of the follower of it, knowledge itself can only refer to pleasure, and that, as he who seeks only pleasure ends in the annihilation of all community of sentiment with others, contradictory even to the inward feelings themselves, so also he who, instead of knowledge, is content with sensuous impressions, can find no community either of men with one another, nor of men with God, but remains confined and isolated within the narrow limits of his own personal consciousness.

These allusions however to the connection between the theoretical and the practical, and consequently between the Theætetus and Gorgias, are found scattered in almost all parts of the dialogue. But the exposition of the theory, that knowledge ought not to be sought in the province of the senses-that, as the only source of pleasure is in the transition from one opposite to the other, so also perception is inconstant, and that whoever thinks to confine knowledge within its province, can never

attain any of the objects of knowledge-forms in its gradual developement, the framework of the whole. Hence the dialogue begins with showing that the Protagorean denial of a general standard of knowledge, and the Heracleitic theory of the flux of all things, and of Becoming alone remaining to the exclusion of all Being, as well as the principle here tried throughout, which sets up Perception, and Perception alone, for knowledge, do all refer to one another, and form one system. Socrates shows this while he supports the principles himself, and mutually upholds them by means of each other better than their authors had done, who in part, perhaps, less perfectly understood themselves, and the connection of their thoughts. And it is not before the Platonic Socrates has thus armed the theory of Protagoras against his own preliminary objections, as well as the nature of the subject admitted of, and exhibited it in a different and more connected form, that the dialogue proceeds to grapple seriously with those theories, and to show that the whole system, in so far as it affects to be knowledge and matter of instruction, falls to pieces of itself, and can never attain its object. Thus, first of all, the theory of Protagoras is attacked on two sides, which the dialogue itself, in order to prevent any misunderstanding, pronounces victorious. First, upon the side of the contradiction involved in the proposition which makes opinion the arbiter of knowledge. For, as long as other men place a knowledge still above opinion, that proposition destroys itself, inasmuch as the number of those to whom a thing appears true, is now the measure of certainty, and the predominant opinion, by the supposition, maintains itself against the value of opinion. Then it is shown that although

it may hold for the time being, that what appears to every one, is, as regards him, yet that it cannot hold for the useful, or for any thing which concerns the future*. Now should any one discover in this conclusion a contradiction to the way in which Plato has already considered the future elsewhere, when he showed that the knowledge of the future is not a particular knowledge, but that only he who is cognizant of the present can possibly be in a condition to judge of the future, he would nevertheless be mistaken. For, in the first place, Plato here places himself at the point of view of those to whom the future is a particular, and then the whole series of conclusions to which Plato intends, cannot still be drawn without taking the antecedent into consideration. Because, for instance, only what the physician thinks about the future fever is the truth; so also, by consequence, only what the physician thinks of the present state of health is the truth, and therefore the knowledge of it is distinct from mere perception. A consequence which Plato himself would have drawn somewhat more definitely, had he not been carried onwards by a press of accumulating investigations and applications, all of which were intended for this dialogue, as indeed he leaves throughout many conclusions in it to be drawn by the reader himself.

Next, and in a manner resembling this, the theory also of Heraclitus which had been already contained in the exposition of that of Protagoras, is attacked inde

* See Theætet. p. 178. A.

Ἔτι τοίνον ἐνθένδε ἂν μᾶλλον πᾶς τις ομολογήσεις ταὐτὰ ταῦτα, εἰ περὶ παντός τις τοῦ εἴδους ἐρωτῴη, ἐν ᾧ καὶ τὸ ὠφέλιμον τυγχάνει ὄν. ἔστι δέ που καὶ περὶ τὸν μέλλοντα χρόνον. ὅταν γὰρ νομοθετώμεθα, &ε.