But we find also in Alkibiadês II. another doctrine, more remarkable. Sokrates will not proclaim absolutely that knowledge is good, and that ignorance is evil. In some cases, he contends, ignorance is good; and he discriminates which the cases are. That which we are principally interested in knowing, is _Good_, or The _Best_--The _Profitable_:[74] phrases used as equivalent. The knowledge of this is good, and the ignorance of it mischievous, under all supposable circumstances. And if a man knows good, the more he knows of everything else, the better; since he will sure to make a good use of his knowledge. But if he does not know good, the knowledge of other things will be hurtful rather than beneficial to him. To be skilful in particular arts and accomplishments, under the capital mental deficiency supposed, will render him an instrument of evil and not of good. The more he knows--and the more he believes himself to know--the more forward will he be in acting, and therefore the greater amount of harm will he do. It is better that he should act as little as possible. Such a man is not fit to direct his own conduct, like a freeman: he must be directed and controlled by others, like a slave. The greater number of mankind are fools of this description--ignorant of good: the wise men who know good, and are fit to direct, are very few. The wise man alone, knowing good, follows reason: the rest trust to opinion, without reason.[75] He alone is competent to direct both his own conduct and that of the society. [Footnote 74: Plato, Alkib. ii. p. 145 C. [Greek: O(/stis a)/ra ti tô=n toiou/tôn oi)=den, e)a\n me\n pare/pêtai au)tô=| ê( tou= belti/stou e)pistê/mê--au)tê\ d' ê)=n ê( au)tê\ dê/pou ê(per kai\ ê( tou= ô)pheli/mou]--also 146 B.] [Footnote 75: Plato, Alkib. ii. p. 146 A-D. [Greek: a)/neu nou= do/xê| pepisteuko/tas.]] The stress which is laid here upon the knowledge of good, as distinguished from all other varieties of knowledge--the identification of the good with the profitable, and of the knowledge of good with reason ([Greek: nou=s]), while other varieties of knowledge are ranked with opinion ([Greek: do/xa])--these are points which, under one phraseology or another, pervade many of the Platonic dialogues. The old phrase of Herakleitus--[Greek: Polumathi/ê no/on ou) dida/skei]--"much learning does not teach reason"--seems to have been present to the mind of Plato in composing this dialogue. The man of much learning and art, without the knowledge of good, and surrendering himself to the guidance of one or other among his accomplishments, is like a vessel tossed about at sea without a pilot.[76] [Footnote 76: Plato, Alkib. ii. p. 147 A. [Greek: o( de\ dê\ tê\n kaloume/nên poluma/theia/n te kai\ polutechni/an kektême/nos, o)rphano\s de\ ô)\n tau/tês tê=s e)pistê/mês, a)go/menos de\ u(po\ mia=s e(ka/stês tô=n a)/llôn], &c.]