Page:Dictionary of Greek and Roman Biography and Mythology (1870) - Volume 3.djvu/412

400 PliATO. the conflict of these principles, each of them unte- nable in its own one-sidedness, had called forth the sophists, and these had either denied knowledge altogether, or resolved it into the mere opinion of momentary affection, Socrates was obliged above all things to show, that there was a knowledge in- dependent of the changes of our sensuous affections, and that this knowledge is actually found in our inalienable consciousness respecting moral require- ments, and respecting the divinity, in conscientious self-intellection. To develope this by induction from particular nianifesiations of the moral and religious sense, and to establish it, by means of definition, in a comprehensible form, — that is, in its generality, — Buch was the point to which his attention had mainly to be directed. Plato, on the contrary, was con- strained to view the question relating to the essence and the material of our knowledge, as well of that Avhich develops itself for its own sake, as of that which breaks out into action, — of the theoretical as well as of the practical, moi'e generally^ and to direct his efforts, therefore, to the investigation of its va- rious forms. In so doing he became the originator of the science of knowledge, — of dialectics. No one before him had gained an equally clear percep- tion of the subjective and objective elements of our knowledge ; no one of the theoretical and the prac- tical side of it ; and no one before him had attempted to discover its forms and its laws. The doctrine of Heracleitus, if we set aside the pos- tulate of a universal world-consciousness, had been weakened down to the idea that knowledge is con- fined to the consciousness of the momentary affec- tion which proceeds from the meeting of the motion of the subject with that of the object ; that each of these affections is equally true, "but that each, on account of the incessant change of the motions, must be a different one. With this idea that of the atomistic theory coincided, inasmuch as it was only by means of arbitrary hypotheses that the latter could get over the consciousness of ever-changing sensuous affections. In order to refute this idea from its very foundation, once for all, Plato's Theaetetus sets forth with great acuteness the doc- trine of eternal generation, and the results which Protagoras had drawn from it (p. 153, &c.) ; he renounces the apparent, but by no means decisive grounds, which lie against it (p. 157, e. &c.) ; but then demonstrates that Protagoras must regard his own assertion as at once true and false ; that he must renounce and give up all determinations re- specting futurity, and consequently respecting uti- lity ; that continuity of motion being presupposed, no perception whatever could be attained ; and that the comparison and combination of the emotions or perceptions presupposes a thinking faculty pe- culiar to the soul (reflection), distinct from mere feeling (pp. 171, &c. 179, 182—184). The man who acknowledges this, if he still will not renounce sensualism, yet will be inclined from his sense-per- ceptions to deduce recollection ; from it, concep- tion ; from conception, when it acquires firmness, knowledge {Phaedo, p. 96, c.) ; and to designate the latter as correct conception ; although he will not be in a condition to render any account of the rise of incorrect conceptions, or of the difference between those and correct ones, unless he presup- poses a knowledge that lies, not merely beyond conception generally, but even beyond correct con- ception, and that carries with it its own evidence {Tlwaet. p. 187). He will also be obliged to give PLATO. up the assertion, that knowledge consists in right conception, united with discourse or explanation ; for even thus an absolutely certain knowledge will be presupposed as the rule or criterion of the ex- planation, whatever may be its more accurate definition (p. 200, c. &c.). Although, therefore, Plato concludes the dialogue with the declara- tion that he has not succeeded in bringing the idea of knowledge into perfect clearness (p. 210, a.), but that it must be something which excludes all change- ableness, something which is its own guarantee, simple, uniform, indivisible (p. 205, c, comp. 202, d.), and not to be reached in the science of num- bers (p. 195, d.) : of this the reader, as he sponta- neously reproduces the investigation, was intended to convince himself (comp. Cliarmid. p. 166, c. 1 69, c. Sophist, p. 220, c). That knowledge, however, grounded on and sustained by logical inference {ahias Xoyiafx^, Meno, p. 98, a., de Rep. iv. p. 431, c), should verify itself through the medium of true ideas (Ti?n. p. 51, c, de Rep. vi. p. 54, d.), can only be considered as the more perfect determina- tion of the conclusion to which he had come in the Theaetetus. But before Plato could pass on to his investiga- tions respecting the modes of development and the forms of knowledge, he was obliged to undertake to determine the objects of knowledge, and to grasp that knowledge in its objective phase. To accomplish this was the purpose of the Sophistes, which immediately attaches itself to the Theaetetus, and obviously presupposes its conclusions. In the latter dialogue it had already been intimated that knowledge can only take place in reference to real existence (Theaet. p. 206, e. and 201, a.). This was also the doctrine of the Eleatics, who nevertheless had deduced the unconditional unity and unchange- ableness of the existent, from the inconceivableness of the non-existent. If, however, non-existence is absolutely inconceivable, then also must error, false conception, be so likewise. First of all, therefore, the non-existent was to be discussed, and shown to have, in some sort, an existence, while to this end existence itself had to be defined. In the primal substance, perpetually undergoing a process of transformation, which was assumed by the Ionian physiologists, the existent, whether understood as duality, trinity, or plurality, cannot find place (p. 242, d.) ; but as little can it (with the Eleatics) be even so much as conceived in thought as something absolutely single and one, without any multiplicity (p. 244, b. &c.). Such a thing would rather again coincide with Non-existence. For a multiplicity even in appearance only to be ad- mitted, a multiformity of the existent must be acknowledged (p. 245, c. d.). Manifold existence, however, cannot be a bare multiformity of the tangible and corporeal (p. 246, a. f.), nor yet a plurality of intelligible incorporeal Essences (Ideas), which have no share either in Action or in Passion, as Euclid and his school probably taught ; since so conceived they would be destitute of any influence on the world of the changeable, and would indeed themselves entirely elude our cognizance (p. 248, a. f.). But as in the Theaetetus, the inconceivableness of an eternal generation, without anything stable, had been the result arrived at (comp. Sophist, p. 249, b.;, so in the Sophistes the opposite idea is disposed of, namely, that the absolutely unchangeable ex- istence alone really is, and that all change is mere