Acoustics, in like manner — The student will be thus conducted to the highest of all studies — Dialectic: and to the region of pure intelligible Forms.
In like manner (continues Sokrates), Acoustics or Harmonics must be studied, not by the ear, listening to and comparing various sounds, but by the contemplative intellect, applying arithmetical relations and theories.[238]
After going through all these different studies, the student will have his mind elevated so as to perceive the affinity of method[239] and principle which pervades them all. In this state he will be prepared for entering on Dialectic, which is the final consummation of his intellectual career. He will then have ascended from the cave into daylight. He will have learnt to see real objects, and ultimately the Sun itself, instead of the dim and transitory shadows below. He will become qualified to grasp the pure Intelligible Form with his pure Intellect alone, without either aid or disturbance from sense. He will acquire that dialectical discursive power which deals exclusively with these Intelligible Forms, carrying on ratiocination by means of them only, with no reference to sensible objects. He will attain at length the last goal of the Dialectician — the contemplation of Bonum per se (the highest perfection and elevation of the Intelligible)[240] with Intellect per se in its full purity: the best part of his mind will have been raised to the contemplation and knowledge of the best and purest entity.[241]
[238] Plato, Republic, vii. p. 531.
[239] Plato, Republic, vii. p. 531 D.
[240] Plato, Republic, vii. p. 532 A. οὕτω καὶ ὅταν τις τῷ διαλέγεσθαι ἐπιχειρῇ, ἄνευ πασῶν τῶν αἰσθήσεων διὰ τοῦ λόγου ἐπ’ αὐτὸ ὃ ἔστιν ἕκαστον ὁρμᾷ, καὶ μὴ ἀποστῇ πρὶν ἂν αὐτὸ ὃ ἔστιν ἀγαθὸν αὐτῇ τῇ νοήσει λάβῃ, ἐπ’ αὐτῷ γίγνεται τῷ τοῦ νοητοῦ τέλει, &c.
[241] Plato, Republic, vii. p. 532 D.
Question by Glaukon — What is the Dialectic Power? Sokrates declares that he cannot answer with certainty, and that Glaukon could not follow him if he did.
I know not whether I ought to admit your doctrine, Sokrates (observes Glaukon). There are difficulties both in admitting and denying it. However, let us assume it for the present. Your next step must be to tell us what is the characteristic function of this Dialectic power — what are its different varieties and ways of proceeding? I would willingly do so (replies Sokrates), but you would not be able to follow me.[242] I would lay before you not merely an image of the truth but the very truth itself; as it appears to me at least, whether I am correct or not — for I ought not to be sure of my own correctness.
[242] Plato, Republic, vii. p. 533 A.