§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.