rROTAGOIUS. 367 sanon and measure of truth. We know scarce anything of the elucidations or limitations with which Protagoras may havo accompanied his general position : and if even Plato, who had good means of knowing them, felt it ungenerous to insult an orphan doctrine whose father was recently dead, and could no longer defend it, 1 much more ought modern authors, who speak with mere scraps of evidence before them, to be cautious how they heap upon the same doctrine insults much beyond those which Plato recognizes. In so far as we can pretend to under- stand the theory, it was certainly not more incorrect than several others then afloat, from the Eleatic school and other philoso- phers ; while it had the merit of bringing into forcible relief, though in an erroneous manner, the essentially relative nature of cognition, 2 relative, not indeed to the sensitive faculty alone, 1 Plato, ThcccteL 18, p. 164, E. OVTI uv, olpat, u 0t/U, elirep ye 6 TOV fTepov Uyov efy u^a iroKku uv ijpvve vvv <5e op^avov aiiTov ovra ftfietf irpoiri]7.aKL^ofiev .... aM.ii 6fj avrol Kivdvv evaouev TOV 6 i iniov eve K' aiiTtJ poTj&elv. This theory of Protagoras is discussed in the dialogue called Thesetctus, p. 152, seq., in a long but desultory way. See Sextus Empiric. Pyrrhonic. Hypol. i, 216-219, et contra Mathemat- icos, vii, 60-64. The explanation which Sextus gives of the Protagorean doctrine, in the former passage, cannot be derived from the treatise of Protagoras himself; since he makes use of the word v7.r] in the philosoph- ical sense, which was not adopted until the days of Plato and Aristotle. It is difficult to make out what Diogenes Lafirtins states about other tenets of Protagoras, and to reconcile them with the doctrine of " man being the measure of all things," as explained by Plato (Diog. Lae'rt. ix, rl, 57).
- Aristotle (in one of the passages of his Metaphysica, wherein he dis-
cusses the Protagorean doctrine, x, i, p. 1053, B.) says that this doctrine comes to nothing more than saying, that man, so far as cognizant, or so far as percipient, is the measure of all things ; in other words, that knowl- edge, or perception, is the measure of all things. This, Aristotle says, is trivial, and of no value, though it sounds like something of importance: flpwrayopaf d 1 uvdpunov <f>riai TTUVTCJV elvai fierpov, uontp uv el TOV i~iaTTj- uova elit&v fy T&V aladavouEvov TovTovf <5' OTI l^ovaiv 6 ftev alcdijatv 6 6e hrwr^pyr* a tyauev elvai uerpa TUV inroneiuivuv. OirQiv 6rj heyuv ^epiTrbv QaiveTai TL ?.iyeiv. It appears to me, that to insist upon the essentially relative nature of cognizable truth, was by no means a trivial cr unimportant doctrine, at Aristo le pronounces it to be; especially when we compare it *ri:h thl
