[203] Plato, Republic, vi. p. 510 D-E. τοῖς ὁρωμένοις εἴδεσι προσχρῶνται, καὶ τοὺς λόγους περὶ αὐτῶν ποιοῦνται, οὐ περὶ τούτων διανοούμενοι, ἀλλ’ ἐκείνων πέρι οἷς ταῦτα ἔοικε, τοῦ τετραγώνου αὐτοῦ ἕνεκα τοὺς λόγους ποιούμενοι καὶ διαμέτρον αὐτῆς, ἀλλ’ οὐ ταύτης ἣν γράφουσι, καὶ τἄλλα οὕτως· αὐτὰ μὲν ταῦτα ἃ πλάττουσί τε καὶ γράφουσιν, ὧν καὶ σκιαὶ καὶ ἐν ὕδασιν εἰκόνες εἰσί, τούτοις μὲν ὡς εἰκόσιν αὖ χρώμενοι, ζητοῦντές τε αὐτὰ ἐκεῖνα ἰδεῖν, ἃ οὐκ ἂν ἄλλως ἴδοι τις ἢ τῇ διανοίᾳ.
[204] Plato, Republic, vi. p. 511 A. οὐκ ἐπ’ ἀρχὴν ἰοῦσαν, ὡς οὐ δυναμένην τῶν ὑποθέσεων ἀνωτέρω ἐκβαίνειν, εἰκόσι δὲ χρωμένην αὐτοῖς τοῖς ὑπὸ τῶν κάτω ἀπεικασθεῖσιν, καὶ ἐκείνοις πρὸς ἐκεῖνα ὡς ἐναργέσι δεδοξασμένοις τε καὶ τετιμημένοις.
Dialectic procedure assumes nothing. It departs from the highest Form, and steps gradually down to the lowest, without meddling with any thing except Forms.
From the geometrical procedure thus described, we must now distinguish the other section — the pure Dialectic. Here the Intellect ascends to the absolute Form, and grasps it directly. Particular assumptions or hypotheses are indeed employed, but only as intervening stepping-stones, by which the Intellect is to ascend to the Form: they are afterwards to be discarded: they are not used here for first principles of reasoning, as they are by the Geometer.[205] The Dialectician uses for his first principle the highest absolute Form; he descends from this to the next highest, and so lower and lower through the orderly gradation of Forms, until he comes to the end or lowest: never employing throughout the whole descent any hypothesis or assumption, nor any illustrative aid from sense. He contemplates and reasons upon the pure intelligible essence, directly and immediately: whereas the Geometer can only contemplate it indirectly and mediately, through the intervening aid of particular assumptions.[206]
[205] Plato, Republic, vi. p. 511 B. τὸ ἕτερον τμῆμα τοῦ νοητοῦ … οὖ αὐτὸς ὁ λόγος ἅπτεται τῇ τοῦ διαλέγεσθαι δυνάμει, τὰς ὑποθέσεις ποιούμενος οὐκ ἀρχὰς ἀλλὰ τῷ ὄντι ὑποθέσεις, οἷον ἐπιβάσεις τε καὶ ὁρμάς, ἵνα μέχρι τοῦ ἀνυποθέτου, ἐπὶ τὴν τοῦ παντὸς ἀρχὴν ἰών, ἁψάμενος αὐτῆς, πάλιν αὖ ἐχόμενος τῶν ἐκείνης ἐχομένων, οὕτως ἐπὶ τελευτὴν καταβαίνῃ, αἰσθητῷ παντάπασιν οὐδενὶ προσχρώμενος, ἀλλ’ εἴδεσιν αὐτοῖς δι’ αὐτῶν εἰς αὐτά, καὶ τελευτᾷ εἰς εἴδη.
[206] Plato, Republic, vi. p. 511 C. σαφέστερον εἶναι τὸ ὑπὸ τῆς τοῦ διαλέγεσθαι ἐπιστήμης τοῦ ὄντος τε καὶ νοητοῦ θεωρούμενον ἢ τὸ ὑπὸ τῶν τεχνῶν καλουμένων, αἷς αἱ ὑποθέσεις ἀρχαί, &c.
Two distinct grades of Cognition — Direct or Superior — Noûs — Indirect or Inferior — Dianoia.
The distinction here indicated between the two different sections of the Intelligible Region, and the two different sections of the Region of Sense — we shall mark (continues Sokrates) by appropriate terms. The Dialectician alone has Noûs or Intellect, direct or the highest cognition: he alone grasps and comprehends directly the pure intelligible essence or absolute Form. The Geometer does not ascend to this direct contemplation or intuition of the Form: he knows it only through the medium of particular assumptions, by indirect Cognition or Dianoia; which is a lower faculty than Noûs or Intellect, yet nevertheless higher than Opinion.
Two distinct grades of Opinion also in the Sensible World — Faith or Belief — Conjecture.
As we assign two distinct grades of Cognition to the Intelligible Region, so we also assign two distinct grades of Opinion to the Region of Sense, and its two sections. To the first of these two sections, or to real objects of sense, we assign the highest grade of Opinion, viz.: Faith or Belief. To the second of the two, or to the images of real objects of sense, we assign the lower grade, viz.: Conjecture.