This is an important point of view, which I shall discuss more at length when I come to the Platonic Theætetus. I bring it to view here only as contrasting with different language held by the Platonic Sokrates in other dialogues; where he insists on the great value and indispensable necessity of self-knowledge, as a preliminary to all other knowledge--upon the duty of eradicating from men's minds that false persuasion of their own knowledge which they universally cherished--and upon the importance of forcing them to know their own ignorance as well as their own knowledge. In the face of this last purpose, so frequently avowed by the Platonic Sokrates (indirectly even in this very dialogue),[41] we remark a material discrepancy, when he here proclaims self-knowledge to be impossible. We must judge every dialogue by itself, illustrating it when practicable by comparison with others, but not assuming consistence between them as a postulate _à priori_. It is a part of Plato's dramatic and tentative mode of philosophising to work out different ethical points of view, and to have present to his mind one or other of them, with peculiar force in each different dialogue. The subject is thus brought before us on all its sides, and the reader is familiarised with what a dialectician might say, whether capable of being refuted or not. Inconsistency between one dialogue and another is not a fault in the Platonic dialogues of Search; but is, on the contrary, a part of the training process, for any student who is destined to acquire that full mastery of question and answer which Plato regards as the characteristic test of knowledge. It is a puzzle and provocative to the internal meditation of the student. [Footnote 41: Plato, Charm. 166 D.] [Side-note: Courage and Temperance are shown to have no distinct meaning, except as founded on the general cognizance of good and evil.] In analyzing the Lachês, we observed that the definition of courage given by Nikias was shown by Sokrates to have no meaning, except in so far as it coincided with the general knowledge or cognition of good and evil. Here, too, in the Charmidês, we are brought in the last result to the same terminus--the general cognition of good and evil. But Temperance, as previously good and defined, is not comprehended under that cognition, and is therefore pronounced to be unprofitable. [Side-note: Distinction made between the special sciences and the science of Good and Evil. Without this last, the special sciences are of no use.]