THE SOPHISTA OF PLATO, &c 153 



tetus, a dialogue which is in reality a critical history of Greek psychology as it existed down 

 to the fourth century, just as the Sophista is virtually a critique of the logic or dialectic of 

 the same and previous eras. The one dialogue exposes the unsoundness or incompleteness of 

 the mental theories of Protagoras, of the Cyrenaics, whose founder Aristippus was Plato's con- 

 temporary and rival, and perhaps of certain other schools whose history is less known to us'. 

 The Sophista, in like manner, passes under review the logical schemes of the Eleatics, of their 

 admirers, the semi-Platonic Megarians, and finally of Antisthenes and the Cynics. Both dia- 

 logues, as I have said, profess to be at the same time exemplifications of the processes which 

 the true dialectician, or, as he is styled in the Sophista, 216e, 253 d, the true philosopher must 

 adopt in his search for scientific truth. The one is a hunt after the true conception of 67ri- 

 aTijuti or science, the other an investigation of the genus and differentiae of the conception 

 implied in the term Sophist; and this fiction^ serves in both cases to bind together the critical 

 and polemical investigations which make up the main body of either dialogue. It lends to 

 each the unity of an organic whole'; and infuses into a critical treatise on an abstruse branch 

 of philosophy the vivacity and interest of a drama. Add to this, that the Sophista helps 

 materially towards a solution of the question, What is Science .-' which is the professed aim of 

 the dialogue which precedes it. It attains this object in two ways. First, by enlarging the 

 conception of that which is not Science, treating the subject on its logical or dialectical, as 

 the ThecEtetus regarded it chiefly on its real or psychological side : and, secondly, by giving 

 rules, illustrated by example, for what Plato considered, as we have seen, one of the main 

 elements of scientific method. And the same analogy holds in respect of the critical or con- 

 troversial portion of either dialogue. As in the Thecetetus it is shewn that the Protagorean 

 dictum, that Truth exists only relatively to its percipient {travTaiv (lerpov uvOowtto^), and the 

 kindred, tliough not identical Cyrenaic dogma, that sense is knowledge, and the sensations the 

 sole criteria of truth (KpiTt'jpia ra irdOri), so far from furnishing tenable definitions of 

 Science, in effect render Science impossible : so in the Sophista the Logic of the Cynics and 

 Eleatics is proved to be more properly an Anti-logic, annihilating all Discourse of Reason, and 

 rendering not only Inference but Judgment, or the power of framing the simplest propositions, 

 a sheer impossibility. 



I have said that the Sophista is first a dialectical exercitation, and secondly a critique more 

 or less hostile of three rival systems of dialectic ; two of which, it may be added, evidently 

 sprang out of the third, and presuppose, if they do not assert, the false assumptions on which 

 that third is founded. It may conduce to greater clearness if I take this critical portion of 

 the dialogue first in order. In defending my position, I shall make no assertions at second 

 hand ; an indulgence to which there is the less temptation, as Plato himself tells us pretty 

 plainly what he means, and where he fails us, Aristotle and the ancient historians of Philosophy 

 supply all that is wanting. 



' The theory that " Science is right Opinion combined with 

 Sensation " is given by Zeller to Antisthenes on grounds which 

 seem highly probable. 



' 1 would not be understood to mean that the pursuit of the 

 Definition is a mere feint in either case, but only that it serves 

 as a Trpotpacris — a natural and probable occasion for the intro- 

 duction of important controversial discussions. It constitutes 



the framework or "plot" of the drama. At the same time I 

 conjecture that the end Plato had most at heart in these two 

 dialogues was the confutation of opponents. In the Politicus, 

 on the other hand, a didactic or constructive intention appears 

 to predominate. 



' Comp. Phcedr. 2G4 C : tel irdirra \6yo¥ uatrtp {oioK avre- 

 aTtivaif ic.T.X. 



Vol. X. Part I. 20 



