§20. _Ingeniis_: rejected by many (so Halm), but cf. _T.D._ III. 2, and _animis_ below and in _N.D._ II. 58. _In naturam et mores_: for _in ea quae natura et moribus fiunt_. A similar inaccuracy of expression is found in II. 42. The division is practically Aristotle's, who severs αρεται into διανοητικαι and ηθικαι (_Nic. Eth._ I. c. 13, _Magna Mor._ I. c. 5). In _D.F._ V. 38 the διανοητικαι are called _non voluntariae_, the ηθικαι _voluntariae_. _Celeritatem ad discendum et memoriam_: cf. the ευμαθεια, μνημη of Arist. (who adds αγχινοια σοφια φρονησις), and the _docilitas, memoria_ of _D.F._ V. 36. _Quasi consuetudinem_: the _quasi_ marks a translation from the Greek, as frequently, here probably of εθισμος (_Nic. Eth._ II. c. 1). _Partim ratione formabant_: the relation which reason bears to virtue is set forth in _Nic. Eth._ VI. c. 2. _In quibus_: i.e. _in moribus_. All the late schools held that ethics formed the sole ultimate aim of philosophy. _Erat_: note the change from _oratio obliqua_ to _recta_, and cf. the opposite change in II. 40. _Progressio_: this, like the whole of the sentence in which it stands, is intensely Stoic. For the Stoic προκορη, προκοπτειν εις αρετην, cf. _M.D.F._ IV. 64, 66, R. and P. 392, sq., Zeller, _Stoics_ 258, 276. The phrases are sometimes said to be Peripatetic, if so, they must belong only to the late Stoicised Peripateticism of which we find so much in Stobaeus. _Perfectio naturae_: cf. esp. _De Leg._ I. 25. More Stoic still is the definition of virtue as the perfection of the _reason_, cf. II. 26, _D.F._ IV. 35, V. 38, and Madvig's note on _D.F._ II. 88. Faber quotes Galen _De Decr. Hipp. et Plat._ c. 5, ‛η αρετη τελειοτης εστι της ‛εκαστου φυσεος. _Una res optima_: the supremacy of virtue is also asserted by Varro in Aug. XIX. 3, cf. also _D.F._ V. 36, 38.
§21. _Virtutis usum_: so the Stoics speak of their αδιαφορα as the practising ground for virtue (_D.F._ III. 50), cf. _virtutis usum_ in Aug. XIX. 1. _Nam virtus_: most MSS. have _iam_, which is out of place here. _Animi bonis et corporis cernitur et in quibusdam_: MSS. omit _et_ between _cernitur_ and _in_, exc. Halm's G which has _in_ before _animi_ and also before _corporis_. These last insertions are not necessary, as may be seen from _Topica_ 80, _causa certis personis locis temporibus actionibus negotiis cernitur aut_ in _omnibus aut_ in _plerisque_, also _T.D._ V. 22. In Stob. II. 6, 8, the τελος of the Peripatetics is stated to be το κατ' αρετην ζην εν τοις περι σωμα και τοις εξωθεν αγαθοις, here _quibusdam quae_ etc., denote the εξωθεν or εκτος αγαθα, the third class in 19. _Hominem ... societate_: all this is strongly Stoic, though also attributed to the Peripatetics by Stob. II. 6, 7 (κοινη φιλανθρωπια), etc., doubtless the humanitarianism of the Stoics readily united with the φυσει ανθρωπος πολιτικον ζωον theory of Aristotle. For Cic. cf. _D.F._ III. 66, _De Leg._ I. 23, for the Stoics, Zeller 293--296. The repetitions _hominem_, _humani_, _hominibus_, _humana_ are striking. For the last, Bentley (i.e. Davies' anonymous friend) proposed _mundana_ from _T.D._ V. 108, Varro, however, has _humana societas_ in Aug. XIX. 3. _Cetera autem_: what are these _cetera?_ They form portion of the εκτος αγαθα, and although not strictly contained within the _summum bonum_ are necessary to enrich it and preserve it. Of the things enumerated in Stob. II. 6, 8, 13, φιλια, φιλοι would belong to the _quaedam_ of Cicero, while πλουτος αρχη ευτυχια ευγενεια δυναστεια would be included in _cetera_. The same distinction is drawn in Aug. VIII. 8. _Tuendum_: most MSS. _tenendum_, but _tuendum_ corresponds best with the division of αγαθα into ποιητικα and φυλακτικα, Stob. II. 6, 13. For the word _pertinere_ see _M.D.F._ III. 54.