368 mSTOEY OF GREECE. but to that reinforced and guided by the other faculties of man memorial and ratiocinative. And had it been even more incor rect than it really is, there would be no warrant for those impu- tations which modern authors build upon it, against the morality of Protagoras. No such imputations are countenanced in the discussion which Plato devotes to the doctrine : indeed, if the vindication which he sets forth against himself on behalf of Protagoras be really ascribable to that sophist, it would give an exaggerated importance to the distinction between Good and Evil, into which the distinction between Truth and Falsehood is considered by the Platonic Protagoras as resolvable. The sub- sequent theories of Plato and Aristotle respecting cognition, were much more systematic and elaborate, the work of men greatly superior in speculative genius to Protagoras : but they would not have been what they were, had not Protagoras, as well as others gone before them, with suggestions more partial and imperfect. From Gorgias there remains one short essay, preserved in one of the Aristotelian, or Pseudo- Aristotelian treatises, 1 on a meta- physical thesis. He professes to demonstrate that nothing exists that if anything exist, it is unknowable ; and granting it even to exist and to be knowable by any one man, he could never com- municate it to others. The modern historians of philosophy here prefer the easier task of denouncing the skepticism of tin unmeasured conceptions of the objects and methods of scientific research which were so common in the days of Protagoras. Compare Metaphysic. iii, 5, pp. 1008, 1009, where it will be seen how many other thinkers of that day earned the same doctiine, seemingly, further than Protagoras. Protagoras remarked that the observed movements of the heavenly bodies did not coincide with that which the astronomers represented them to be, and to which they applied their mathematical reasonings. This remark was a criticism on the mathematical astronomers of his day I7.eyx<>>v roi)f -yeufierpaf (Aristot. Metaph. iii, 2, p. 998, A). We know too little how far his criticism may have been deserved, to assent to the general Btrictnres of Bitter, Gesch. der Phil. vol. i, p. 633. 1 See the treatise entitled De Melisso, Xenophane et Gorgia in Bekker's edition of Aristotle's Works, vol. i, p. 973, seq. ; also the same treatise, with a good preface and comments, by Mullach, D. 62. seq. : compare Sextus . adv. Mathemat. vii, 65, 87.
