[50] Plato, Polit. pp. 259 C-D, 305 D.
[51] See the preface to Xenophon’s Cyropædia; also Cyropæd. i. 6, 20; and his Œcon. c. 21, and c. 13, 4, where we see the difference between the Xenophontic idea, and the Platonic idea, of ὁ ἀρχικὸς ἀνθρώπων, οἱ θεῖοι καὶ ἀγαθοὶ καὶ ἐπιστήμονες ἄρχοντες.
The theory in the Politikus is the contradiction to that theory which is assigned to Protagoras in the Protagoras.
Plato here sets forth the business of governing as a special art, analogous to the special art of the weaver, the steersman, the physician. Now in each special art, the requisite knowledge and competence is possessed only by the one or few artists who practise them. The knowledge possessed by such one or few, suffices for all the remaining community; who benefit by it, but are altogether ignorant on the matter, and follow orders blindfold. As this one Artist is the only competent person for the task, so he is assumed quâ Artist, to be infallible in the performance of the task — never to go wrong, nor to abuse his power, nor to aim at any collateral end.[52] Such is Plato’s theory of government in the Politikus. But if we turn to the Protagoras, we shall find this very theory of government explicitly denied, and a counter-theory affirmed, in the discourse put into the mouth of Protagoras. That Sophist is made to distinguish the political or social art, upon which the possibility of constituting or keeping up human society depends, from all other arts (manual, useful, linguistic), by this express characteristic: All other arts were distributed among mankind in such manner, that knowledge and skill were confined to an exclusive few, whose knowledge, each in his own special department, sufficed for the service of all the rest, not favoured with the like knowledge — but the political or social art was distributed (by order of Zeus to Hermes) on a principle quite opposite. It was imparted to every member of society without exception. If it had been granted only to a few, and not to all, society could not have held together. Justice and the sense of shame (Temperance or Moderation), which are the bonds of the city and the fruits of the political art, must be instilled into every man. Whoever cannot take on and appropriate them (Zeus proclaims it as his law), must be slain as a nuisance or distemper of the city.[53]
[52] Compare Plato, Republic, i. pp. 340-341.
[53] Plato, Protag. pp. 322, 325 A.
Points of the Protagorean theory — rests upon common sentiment.
Such we have seen to be the theory enunciated by the Platonic Protagoras (in the dialogue so-called) respecting the political or social art. It pervades all the members of society, as a common and universal attribute, though each man has his own specialty besides. It was thus distributed at the outset by Zeus. It stands embodied in the laws and in the unwritten customs, so that one man may know it as well as another. Every man makes open profession of knowing and possessing it:— which he cannot do with any special art. Fathers enforce it on their children by rewards and punishments, schoolmasters and musicians impart it by extracts from the poets: the old teach it to the young: nay every man, far from desiring to monopolise it for himself, is forward in teaching it to others: for it is the interest of every one that his neighbour should learn it. Since every one thus teaches it, there are no professed or special teachers: yet there are still some few who can teach it a little better than others — and among those few I (says Protagoras) am one.[54]
[54] Plato, Protag. pp. 327-328.
Counter-Theory in the Politikus. The exigencies of the Eleate in the Politikus go much farther than those of Protagoras.