mind to a greater or less degree, and towards some persons more than towards others. [Footnote 64: Plato, Theætêt. p. 161 D. [Greek: o( d' a)/ra e)tu/gchanen ô)\n ei)s phro/nêsin ou)de\n belti/ôn batra/chou guri/nou, mê\ o(/ti a)/llou tou a)nthrô/pôn.] I substitute the dog or horse as illustrations.] [Side-note: Belief on authority is true to the believer himself--The efficacy of authority resides in the believer's own mind.] Belief on authority is true to the believer himself, like all his other beliefs, according to the Protagorean doctrine: and in acting upon it,--in following the guidance of A, and not following the guidance of B,--he is still a measure to himself. It is not to be supposed that Protagoras ever admitted all men to be equally wise, though Plato puts such an admission into his mouth as an inference undeniable and obvious. His doctrine affirms something altogether different:--that whether you believe yourself to be wise or unwise, in either case the belief is equally your own--equally the result of your own mental condition and predisposition,--equally true to yourself,--and equally an item among the determining conditions of your actions. That the beliefs and convictions of one person might be modified by another, was a principle held by Protagoras not less than by Sokrates: the former employed as his modifying instrument, eloquent lecturing--the latter, dialectical cross-examination. Both of them recognise the belief of the person to whom they address themselves as true to him, yet at the same time as something which may be modified and corrected, by appealing to what they thought the better parts of it against the worse. [Side-note: Protagorean formula--is false, to those who dissent from it.] Again--Sokrates imputes it as a contradiction to Protagoras--"Your doctrine is pronounced to be false by many persons: but you admit that the belief of all persons is true: therefore your doctrine is false".[65] Here also Plato omits the qualification annexed by Protagoras to his general principle--Every man's belief is true--that is, true _to him_. That a belief should be true, to one man, and false to another--is not only no contradiction to the formula of Protagoras, but is the very state of things which his formula contemplates. He of course could only proclaim it as true to himself. It is the express purpose of his doctrine to disallow the absolutely true and the absolutely false. His own formula, like every other opinion, is false to those who dissent from it: but it is not false absolutely, any more than any other doctrine. Plato therefore does not make out his charge of contradiction. [Footnote 65: Plato, Theætêt. p. 171 A. Sextus Empiric. (adv. Mathem. vii. 61) gives a pertinent answer to this objection.] [Side-note: Plato's argument--That the wise man alone is a measure--Reply to it.]