§40. _Quasi fundamenta_: a trans. probably of θεμελιος or the like; cf. ‛ωσπερ θεμελιος in Sext. _A.M._ V. 50. _Artem_: method, like τεχνη, cf. _M.D.F._ III. 4, Mayor on Iuv. VII. 177. _Vim_: the general character which attaches to all φαντασιαι; _genera_ the different classes of φαντασιαι. _Totidem verbis_: of course with a view to showing that nothing really corresponded to the definition. Carneades largely used the _reductio ad absurdum_ method. _Contineant ... quaestionem_: cf. 22 and _T.D._ IV. 65 _una res videtur causam continere_. _Quae ita_: it is essential throughout this passage to distinguish clearly the _sensation_ (_visum_) from the _thing_ which causes it. Here the _things_ are meant; two _things_ are supposed to cause two _sensations_ so similar that the person who has one of the _sensations_ cannot tell from which of the two _things_ it comes. Under these circumstances the sceptics urge that it is absurd to divide _things_ into those which can be perceived (known with certainty) and those which cannot. _Nihil interesse autem_: the sceptic is not concerned to prove the absolute similarity of the two sensations which come from the two dissimilar things, it is enough if he can show that human faculties are not perfect enough to discern whatever difference may exist, cf. 85. _Alia vera sunt_: Numenius in Euseb. _Pr. Ev._ XIV. 8, 4 says Carneades allowed that truth and falsehood (or reality and unreality) could be affirmed of _things_, though not of _sensations_. If we could only pierce _through_ a sensation and arrive at its source, we should be able to tell whether to believe the sensation or not. As we cannot do this, it is wrong to assume that _sensation_ and _thing_ correspond. Cf. Sext. _P.H._ I. 22 περι μεν του φαισθαι τοιον η τοιον το ‛υποκειμενον (i.e. the thing from which the appearance proceeds) ουδεις ισως αμφισβητει, περι δε του ει τοιουτον εστιν ‛οποιον φαινεται ζητειται. Neither Carneades nor Arcesilas ever denied, as some modern sceptics have done, the actual existence of things which cause sensations, they simply maintained that, granting the existence of the things, our sensations do not give us correct information about them. _Eiusdem modi_: cf. 33 _eodem modo_. _Non posse accidere_: this is a very remarkable, and, as Madv. (_D.F._ I. 30) thinks, impossible, change from _recta oratio to obliqua_. Halm with Manut. reads _potest_. Cf. 101. §41. _Neque enim_: a remark of Lucullus' merely. _Quod sit a vero_: cf. Munio on Lucr. II. 51 _fulgor ab auro_. _Possit_: for the om. of _esse_ cf. n. on I. 29.