In strict accordance with this interpretation of Plato's latent meaning, his philosophy is distributed under three heads: I. Dialectical Philosophy; II. Theoret- ical, Contemplative, or Physical ; III. Practical (Cicero, Acad. Qucest. i, 5, § 19). The second and third divis- ions are subdivided. This distribution is not distinct- ly proposed in Plato's works, but it is implied in them. It is accredited by Sextus Empiricus to Xenocrates, Plato's second successor in the Academy. The terms employed are earlier than Plato, as are the inquiries also. It must not be forgotten that though Plato was in the main Socratic, he was also a votary of other doc- trines— Eclectic, if not Synergistic, and, in his later writings, largely Pythagorean.
I. Dialectical Philosophy. — The term "Dialectics" includes in Plato much more than it does in Aristotle (Sophist, p. 253 ; De Rep. vii. 532-535 ; Aristotle. Topic. i, I. Sophist. Elench. xxxii; MetapkAi,l; iii. 2. Ehet. i, 2). It is not confined to the art of probable argu- mentation, but comprehends the whole theory of knowl- edge, the characteristics of correct and incorrect reason- ing, the conduct of the understanding, and so much of psychology as is concerned with the operations of the mind in the acquisition, estimation, and communication of knowledge. This wide range may be illustrated by lord Bacon's inclusion under Logic of the Aries Inveni- endi, Judicandi, Retinendi, et Tradendi (De Avgm. Sci. v, 6).
There is a fundamental enigma which demands so- lution at the commencement of all inquiry, and which has been designated the problem of certitude. How can we know that we know what we think we know? How does knowledge arise? how is its credibility or validity ascertained? What degree of credibility be- longs to it? These questions were never dogmatically answered by Plato, unless it were the last. A positive answer would have been a repudiation of the Socratic profession of ignorance and uncertainty (Aristot. Soph. Elench. xxxiii). But he labored assiduously in all his treatises to exemplify the conditions of true knowledge, and he contributed efficiently to their determination. Knowledge, in ordinary, according to Plato, is acquired through the senses, but it. is not determined by sense: it is determined by the knowing mind. This is an ap- proximation at once to Kant's forms of the understand- ing, and to Leibnitz's acute reply to the maxim. " Nihil in intellectu quod non prius in sensu," by the addition of
PLATONIC PHILOSOPHY
284
PLATONIC PHILOSOPHY
"nisi intellectus ipse." The mind is it- own place. It
itself, and of all the world beside. Sense is an
of the mind through the intervention of the
corporeal sensibilities. Permanent impressions made
ire retained by the faculty of memory.
I ition of remembrances with sensible experi-
nstitutes opinion true opinion when they
se opinion when they arc discordant (Phileb.
p. :;i ; ,. The knowledge of things in
time is uncertain, and amounts only to opinion. The
human mind may be conceived to I"- a tablet of wax,
■ and to retain any impri ssion. This is.
qi r< ly an illustration . ["houghl
i- the communing of the mind with itself.
lible utterance of thought. Words are not knowledge, but only the means and vehicle of knowl- Tkeatet.y. 191,202). Intelligence, or real knowledge, is the action of the mind in the contemplation of the prime Intel* incorporeal types of being. !i is twofold; the first is the perception of the soul, which beheld its appropriate . before descending into 1 1 j « - body; the sec- ond, or natural knowledge, is that which the mind re- bile enveloped in its carnal integument. The latter, or mundane know ledge, is the restored but broken i ,i of what had been known in a pre-existenl stair, and must be distinguished from the acquisitions of memory, being concerned with things intelligible, as the other is with things sensible (Timceus, p. 30 ; Pka- don, p. 71 76; comp. Wordsworth, Odt on Intimations 'ality, etc.). This doctrine of reminiscence is a peculiarly Platonic fancy, and fascinated the later Platonists to such an extent that Synesius declined a bishopric in tin- Christian Church rather than renounce the dream. It is implicated, as cause or consequence,
with the doctri if the Platonic ideal, as both are u 1th
I ic process by which Socrates and Plato si ro\ e ti. dissipate error and to evolve truth from the minds <>f their hearers. The midwifery of the mind which Socrates professed, and which Plato represented him as professing, necessitated the assumption that truth was lOtentially in the mind, and that it only re- quired to he drawn from its latent state by adroit hand- ling. It could not he latent, nor could it be brought forth, unless it lay then- like a chrysalis, and descended from an .anterior condition of being. It was in a super- terrestrial and antemundane existence that souls had acquired
mm sensnm, arqne anrai simplicis ignem;" luit before their demission, or return to earth, they had d in oblivion, el immemores supera ut convexa revisant." The acquisition of genuine knowledge was thus the res- toration of the obliterated memories of supernal real- ities Absurd and extravagant a.- this tenet appears in it- Platonic form, it was a dreamy and ineffectual ve definite expression to the mysterious proc- ess of thought. The doctrine was modified and trans- form, d by St. Augustine so as to deprive it of its wild- nationality. He conceived the human mind I iimied iii perfect harmony with the universe.