Sec.25. Oportet videri:  “ought to be seen.”  For this use cf. 39, 81 and 122 of this book. Videri at the end of this section has the weak sense, “to seem.”  Lucretius often passes rapidly from the one use to the other; cf.  I. 262 with I. 270, and Munro’s n., also M.D.F. II. 52, Em.  Liv. p. 42. Non poterit:  as the Academics allege. Naturae ... alienum:  Cic. uses this adjective with the dat, and also with the ablative preceded by ab; I doubt whether the phrase maiestate alienum (without the preposition) can be right in De Div. II. 102, where the best texts still keep it. Non occurrit ... aget:  occurrit is probably the perfect.  Cf. n. on 127.

Sec.26. Quid quod si:  Goer., outrageously reads quid quod si, si. Tollitur:  the verb tollere occurs as frequently in this sense as [Greek:  anairein] does in Sextus. Lux lumenque:  Bentl. dux The expression dux vitae is of course frequent (cf. N.D. I. 40, T.D. V. 5 and Lucretius), but there is no need to alter. Lux is properly natural light, lumen artificial, cf. Ad Att. XVI. 13, 1. lumina dimiseramus, nec satis lucebat, D.F.  III. 45 solis luce ... lumen lucernae.  There is the same difference between [Greek:  phos] and [Greek:  phengos], the latter is used for the former ([Greek:  phengos heliou]) just as lumen is for lux (si te secundo lumine his offendere—­Ad Att. VII. 26, 1) but not often vice versa.  Trans. “the luminary and the lamp of life,” and cf.  Sext. Adv.  Math. VII. 269 where the [Greek:  phantasia] is called [Greek:  phengos]. Finis:  so in the beginning of the Nicom.  Eth. Aristot. assumes that the actual existence of human exertion is a sufficient proof that there is a [Greek:  telos]. Aperta:  a reminiscence of the frequently recurring Greek terms [Greek:  ekkalyptein, ekkalyptikos] etc., cf.  Sextus passim, and D.F. I. 30. Initium ... exitus = [Greek:  arche ... telos]. Tenetur:  MSS. tenet, the nom. to which Guietus thought to be ratio above. [Greek:  Apodeixis]:  cf. the definition very often given by Sext. e.g. Pyrrh.  Hyp. II. 143 [Greek:  logos di’ homologoumenon lemmaton] (premisses) [Greek:  kata synagogen epiphoran] (conclusion) [Greek:  ekkalypton adelon], also Diog.  VII. 45, [Greek:  logon dia ton mallon katalambanomenon to hetton katalambanomenon perainonta] (if the reading be right).

Sec.27. Notio:  another trans. of [Greek:  ennoia]. Conclusisse:  although the Greeks used [Greek:  symperasma] instead of [Greek:  epiphora] sometimes for the conclusion of the syllogism, they did not use the verb [Greek:  symperainein] which has been supposed to correspond to concludere.  It is more likely to be a trans. of [Greek:  synagein], and conclusum argumentum of [Greek:  synaktikos