PLATO 207 ite- the champion of ordinary morality ; he is now made the exponent of ordinary thinking. His saying " Man the measure " is shown to rest on the unstable basis of the Heraclitean flux. By an elaborate criticism of both theories knowledge is at last separated from the relativity of sense ; but the subsequent attempt to distinguish on abstract grounds between true and false opinion, and to. define knowledge as true opinion with a reason (comp. Meno), proves ineffectual. Plato still shows traces of Megarian influence. But the disjunctive method of the Parmenides is not resumed. The indirect proofs are so arranged as to exhibit the skill of Socrates in " bringing to the birth " the germs of thought in a richly-endowed and " pregnant " young mind. Thesetetus is the embodiment of the philosophic nature described in Rep., bk. vi., and has already been trained by Theodorus of Gyrene in geometry and the other preparatory sciences of Rep., bk. vii. It is in conversation with Theodorus that Socrates impressively contrasts the lives of the lawyer and the philosopher. The Thesetetus marks a great advance in clearness of meta physical and psychological expression. See for example the passage (184-186) in which the independent function of the mind is asserted, and ideas are shown to be the truth of experience. There is also a distinct approach towards a critical and historical method in philosophy, while the per fection of style continues unimpaired, and the person of Socrates is as vividly represented as in any dialogue. Notwithstanding the persistence of an indirect and negative method, the spirit of this dialogue also is the reverse of sceptical. " Socrates must assume the reality of knowledge or deny himself " (197 A). Perhaps in no metaphysical writing is the balance more firmly held between experience, imagination, and reflexion. Plato would seem to have made a compact with himself to abstain rigidly from snatching at the golden fruit that had so often eluded his grasp, and to content himself with laboriously " cutting steps " towards the summit that was still unsealed. ist. With Plato, as with other inventive writers, a time seems to have arrived when he desired to connect succes sive works in a series. Thus in planning the Sophistes he linked it to the Thesetetus (which had been written with out any such intention), and projected a whole tetralogy of dialectical dialogues, Thesetetus, Sophistes, Politicus, Philosophus, of which the last piece seems never to have been written. After an interval, of which our only measure is a change of style, the philosopher returns to the great central question of knowledge and being. The obstacle in his path, on which he has often played with light satire, dramatic portraiture, and indirect allusion, is now to be made the object of a seriously planned attack. He has made his approaches, and the enemy s fortress is to be forthwith sapped and overthrown. This hostile position is not merely the " Sophistik " which, as some tell us, is an invention of the Germans, and as Plato himself declares is only the reflexion or embodiment of the average mind, 1 but the fallacy of fallacies, the prime falsehood (jrpwTov i/ evSos) of all contemporary thought. This is nothing else than the crude absoluteness of affirmation and negation which was ridiculed in the Eiithydemus, and has been elsewhere mentioned as the first principle of the art of controversy. 2 For dramatic purposes this general error is personified. And the word " sophist," which had somehow become the bete noire of the Platonic school, thus for the first time fixedly acquires the significance which has since clung to the name. That Plato himself would not adhere pedantically to the connotation here implied is shown by 1 Rep., vi. 493. - b.vrioyiK-h. the admission, at the opening of the dialogue, that amongst other disguises under which the philosopher walks the earth, the sophist is one. In this dialogue, as in the Parmenides, a new method is introduced, and again by an Eleatic teacher. This method is repeated with improvements in the Politicus, and once more referred to in the Philebus. It bears a strong resemblance to the " synagoge" and " diteresis" of the Phsedrus, but is applied by the " friend from Elea " with a degree of pedantry which Socrates nowhere betrays. And the two methods, although kindred, have probably come through different channels, the classifications of the Phsedrus being Plato s own generalization of the Socratic process, while the dichotomies of the Sophistes and Politicus are a caricature of Socrates cast in the Megarian mould. Plato seems to have regarded this method as an implement which might be used with advantage only when the cardinal principles on which it turned had been fully criticized. 1. After various attempts to "catch the sophist," he is defined as the maker of an unreal likeness of truth. Here the difficulty begins for the definition implies the existence of the unreal, i.e., of not-being. In our extremity it is necessary to " lay hands on our father Parmenides." 2. The contradictions attendant on the notion of "being," whether as held by Parmenides or his opponents or by the " less exact " thinkers who came after them, are then examined, and in an extremely subtle and suggestive passage (246-249) an attempt is made to mediate between idealism and materialism. The result is that while consummate being is exempt from change it cannot be devoid of life and motion. Like children, Give us both, say we. " 3. This leads up to the main question : () are different notions incommunicable, or (b) are all ideas indiscriminately communicable, or (c) is there communion of some kinds and not of others ? The last view is alone tenable, and is confirmed by experience. And of the true combination and separation of kinds the philosopher is judge. 4. Then it is asked (in order to "bind the sophist ) whether being is predicable of not-being. Five chief kinds (or categories) are now examined, viz., being, rest, motion, sameness, difference. Rest and motion are mutually incommunicable, but difference is no less universal than being itself. For everything is "other" than the rest, i.e., is not. Thus positive and negative not only coexist but arc coextensive. 5. And, in spite of Parmenides, we have discovered the existence, and also the nature, of not-being. It follows that the mere pur suit of contradictions is childish and useless and wholly incompa tible with a philosophic spirit. Negation, falsity, contradiction, are three notions which Plato from his height of abstraction does not hold apart. His position is the converse of the Spinozistic saying, "Omnis determinatio est negatio." According to him, every negative implies an affirmative. And his main point is that true negation is correlative to true affirmation, much as he has said in the Phsedrus that the dialectician separates kinds according to the "lines and veins of nature." The Sophistes is a standing protest against the error of marring the finely-graduated lineaments of truth, and so destroying the vitality of thought. The idealists whom the Eleatic stranger treats so gently have been identified with the Megarians. But may not Plato be reflecting on a Megarian influence operating within the Academy ? Here, as partly already in the Parmenides and Thesetetus, the ideas assume the nature of categories, and being is the sum of positive attributes, while negation, as the shadow of affirmation, is likewise finally comprehended in the totality of being. The remark made incidentally, but with intense em phasis, that the universe lives and moves " according to God," is an indication of the religious tone which reappears increasingly in the Politicus, Philebus, Timseus, and Lav:s. In passing on to consider the statesman, true and false, Politicus the Eleatic stranger does not forget the lesson which has (States-
just been learned. While continuing his method of dicho- 1T