Plato Republic 7.526

ed. John Burnet

Republic. Plato. ed. John Burnet. Oxford. 1905.

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Πολιτεία (Greek) (Platonis Opera Tomus IV: Tetralogia VIII. Burnet, John, editor. Oxford: Clarendon Press, 1905.)

Translations (1)
Republic Perseus (Plato in Twelve Volumes, Vol. 5-6. Shorey, Paul, translator. Cambridge, MA, Harvard University Press; London, William Heinemann Ltd. 1935-37 (printing).) — 7.526 focus

Commentary

Commentary on Plato, Republic (Plato. The Republic, Vol 1-2. Adam, James, editor. Cambridge: Cambridge University Press, 1902-1903.) focus

περὶ ποίων κτλ. On the derisive ποῖος see 522 D n. Mathematical units are in every case ( ἕκαστον) equal each to each ( πᾶν παντί), and destitute of parts; whereas sensible units (e.g. one horse, one cow etc.) are not equal to each other, and are divisible. In πᾶν παντί Plato copies the formal language of mathematics: cf. ἑκατέραν ἑκατέρᾳ and the like in Euclid passim. For the sense see Phil. 56 C ff., where these two kinds of number are made the basis of a distinction between philosophical or scientific and popular or unscientific ἀριθμητική. It should be carefully noted that a plurality of mathematical units is expressly recognised both here ( ἴσον τε ἕκαστον πᾶν παντί κτλ.) and in Phil. l. c. ( μονάδα μονάδος ἑκάστης τῶν μυρίων μηδεμίαν ἄλλην ἄλλης διαφέρουσαν). This entirely confirms what Aristotle tells us, viz. that Plato placed μαφηματικά between αἰσθητά and εἴδη, τῷ τὰ μὲν πόλλ’ ἄττα ὅμοια εἶναι, τὸ δὲ εἶδος αὐτὸ ἓν ἕκαστον μόνον ( Met. A 6. 987^{b} 14 ff.). There are therefore three kinds of μονάδες in Plato's scheme—the Ideal μονάς, of which only one exists, the Mathematical and the Sensible, of each of which there are many. See on VI 510 D and App. I, where I have quoted further evidence on this subject, and endeavoured to explain the philosophical truth which is contained in the Platonic doctrine of mathematical numbers, magnitudes etc. as intermediates between the Ideas and sensibles.

ὧν κτλ. ὧν is for περὶ ὧν rather than <*> (as J. and C. hold): cf. VI 510 D οὐ περὶ τούτων διανοούμενοι, and (for the grammatical construction) III 402 A note διανοηθῆναι should be understood in the technical sense of VI 511 E.

τῷ ὄντι ἀναγκαῖον . Perhaps with a play on προσαναγκάζον (J. and C.): see on τῷ ὄντι VI 511 B.

ὀξεῖς κτλ. Plato was very emphatic on this point: see Laws 747 B and 819 C φύονται was restored by Schneider from the best MSS. Earlier editions read φαίνονται on inferior authority.

ἂν ‐‐ γυμνάσωνται κτλ. Even Isocrates admits this, although his self-styled ‘Philosophy’ was something very different from Plato's: see Antid. 265—266, especially γυμνασίαν μέντοι τῆς ψυχῆς καὶ παρασκευὴν φιλοσοφίας καλῶ τὴν διατριβὴν τὴν τοιαύτην (mathematical studies).

ἅ γε μείζω κτλ. is an important principle with Plato, who does not believe in any royal road to learning: cf. 530 C and VI 503 E. In antiquity, while algebra was still unknown, ἀριθμητική must have taxed the powers of thought far more than now, and been, from the Platonic point of view, all the more valuable on that account as an educative discipline. The treatment of numbers by Euclid Books VII—X will illustrate Plato's observation: see Gow Gk Math. pp. 74—85, with De Morgan's remarks there quoted.

ὡς τοῦτο . ὡς=‘quam’ instead of ἤ is found sporadically in Greek literature after comparatives: see my note on Ap. 30 B , 36 D. To say that in all such cases the comparative is equivalent to οὕτω with the positive is only to shelve the difficulty; and it is better to recognise the usage as exceptional than summarily to dismiss it as a barbarism (with Thompson on Gorg. 492 E ). J. and C. after οὐδὲ πολλά supply ἃ πόνον οὕτω μέγαν παρέχεται, but the ellipse is too difficult, especially as οὐδὲ πολλά is only a kind of afterthought to or elaboration of οὐ ῥᾳδίως.

τὸ ἐχόμενον τούτου . If γεωμετρία i.e. ἡ τοῦ ἐπιπέδου (plane surfaces) πραγματεία (528 D) concerns itself with δευτέρα αὔξη, and Stereometry with τρίτη αὔξη, we may infer that ἀριθμητική deals with the πρώτη αὔξη, i.e. presumably the line, which, according to the Pythagoreans, is a collection of points (cf. Laws 894 A and Rothlauf l.c. p. 51). And in point of fact the line represented number among the Pythagoreans exactly as the point is the geometrical symbol for the unit: cf. IX 587 D note Hence ἐχόμενον τούτου: we take the δευτέρα αὔξη after the first. See also App. II to this Book, and App. I to Book VIII Part I § 2.

ἢ γεωμετρίαν κτλ. The sequence —Geometry after ἀριθμητική—was probably a usual one with teachers, even in Plato's time: see Grasberger Erziehung u. Unterricht II p. 340 and cf. App. II.

ὅσον μὲν κτλ. is exactly the attitude of the historical Socrates, as Krohn ( Pl. St. p. 376) and others have pointed out, comparing Xen. Mem. IV 7. 2 ff. Practical necessities of this kind probably originated the science (Gow Gk Math. pp. 134 ff.) and gave it its name γεωμετρία. The name μαθήματα (or μαθηματικά) in the special sense of Mathematics owes its origin, no doubt, to the position occupied by mathematical studies in Plato's μαθήματα: but the usage itself is not found till Aristotle (Rothlauf l.c. p. 18), although it is clear from [ Epin.] 990 D, that some Platonists resented the γελοῖον ὄνομα γεωμετρίαν. Glauco represents the practical point of view throughout: cf. 527 D.

καὶ πορείαις . “Scriptum vellem καὶ ἐν πορείαις” (Stallbaum). The idiom is common enough: see KühnerBlass Gr. Gr. II 1, p. 548.

τὸ εὐδαιμονέστατον τοῦ ὄντος is cited by Stumpf (l.c. p. 95 note 3) in support of his identification of the Idea of Good with God: see on VI 505 A.

γένεσιν . 519 A note