Note 101 — Chapter XXVIII · THEÆTETUS.

Schleiermacher represents Plato as discriminating Knowledge (the region of infallibility, you either possess it or not) from Opinion (the region of fallibility, true or false, as the case may be) by a broad and impassable line —

“Auch hieraus erwächst eine sehr entscheidende, nur ebenfalls nicht ausdrücklich gezogene, Folgerung, dass die reine Erkenntniss gar nicht auf demselben Gebiet liegen könne mit dem Irrthum — und es in Beziehung auf sie kein Wahr und Falsch gebe, sondern nur ein Haben oder Nicht Haben.” (Schleiermacher, Einleit. zum Theæt. p. 176.)

Steinhart (in his Einleit. zum Theæt. p. 94) contests this opinion of Schleiermacher (though he seems to give the same opinion himself, p. 92). He thinks that Plato does not recognise so very marked a separation between Knowledge and Opinion: that he considers Knowledge as the last term of a series of mental processes, developed gradually according to constant laws, and ascending from Sensible Perception through Opinion to Knowledge: that the purpose of the Theætêtus is to illustrate this theory.

Ueberweg, on the contrary, defends the opinion of Schleiermacher and maintains that Steinhart is mistaken (Aechtheit und Zeit. Platon. Schriften, p. 279).

Passages may be produced from Plato’s writings to support both these views: that of Schleiermacher, as well as that of Steinhart. In Timæus, p. 51 E, the like infallibility is postulated for Νοῦς (which there represents ἐπιστήμη) as contrasted with δόξα. But I think that Steinhart ascribes to the Theætêtus more than can fairly be discovered in it. That dialogue is purely negative. It declares that ἐπιστήμη is not αἴσθησις. It then attempts to go a step farther towards the affirmative, by declaring also that ἐπιστήμη is a mental process of computation, respecting the impressions of αἴσθησις — that it is τὸ συλλογίζεσθαι, which is equivalent to τὸ δοξάζειν: compare Phædrus, 249 B. But this affirmative attempt breaks down: for Sokrates cannot explain what τὸ δοξάζειν is, nor how τὸ δοξάζειν ψευδῆ is possible; in fact he says (p. 200 B) that this cannot be explained until we know what ἐπιστήμη is. The entire result of the dialogue is negative, as the closing words proclaim emphatically. On this point many of the commentators agree — Ast, Socher, Stallbaum, Ueberweg, Zeller, &c.

Whether it be true, as Schleiermacher, with several others, thinks (Einl. pp. 184-185), that Plato intends to attack Aristippus in the first part of the dialogue, and Antisthenes in the latter part, we have no means of determining.