the New Academy would put an end
to all processes of reasoning. The fleeting and uncertain can never be
discovered. Rational proof requires that something, once veiled, should
be brought to light (26). Syllogisms are rendered useless, philosophy
too cannot exist unless her dogmas have a sure basis (27). Hence the
Academics have been urged to allow their _dogma_ that perception is
impossible, to be a certain perception of their minds. This, Carneades
said, would be inconsistent, since the very dogma excludes the
supposition that there can be _any_ true perception (28). Antiochus
declared that the Academics could not be held to be philosophers if
they had not even confidence in their one dogma (29).

Sec.19. _Sensibus_: it is important to observe that the word _sensus_ like
[Greek: aisthesis] means two things, (1) one of the _five_ senses, (2) an
individual act of sensation. _Deus_: for the supposed god cf. _T.D._ II.
67. _Non videam_: this strong statement is ridiculed in 80. _De remo
inflexo et de collo columbae_: cf. 79, 82. The [Greek: kope enalos
keklasmene] and [Greek: peristeras trachelos] are frequently mentioned,
along with numerous other instances of the deceptiveness of sense, by Sext.
Emp., e.g. _Pyrrhon. Hypot._ I. 119-121, _Adv. Math._ VII. 244, 414.
Cicero, in his speech of the day before, had probably added other examples,
cf. Aug. _Cont. Ac._ III. 27. _Epicurus hoc viderit_: see 79, 80. Epic.
held all sensation, _per se_, to be infallible. The chief authorities for
this are given in R. and P. 343, 344, Zeller 403, footnote. _Lumen mutari_:
cf. _Brut._ 261. _Intervalla ... diducimus_: for this cf. Sext. _Pyrrh_. I.
118 [Greek: pemptos esti logos] (i.e. the 5th sceptic [Greek: tropos] for
showing sense to be untrustworthy) [Greek: ho para tas theseis] (_situs_)
[Greek: kai ta diastemata] (_intervalla_) [Greek: kai tous topous].
_Multaque facimus usque eo_: Sext. _Adv. Math._ VII. 258 [Greek: panta
poiei mechris an tranen kai plektiken spase phantasian]. _Sui iudicii_: see
for the gen. _M.D.F._ II. 27; there is an extraordinary instance in Plaut.
_Persa_ V. 2, 8, quoted by Goer. _Sui cuiusque_: for this use of _suus
quisque_ as a single word see _M.D.F._ V. 46.

Sec.20. _Ut oculi ... cantibus_: Halm after Dav. treats this as a gloss: on
the other hand I think it appropriate and almost necessary. _Quis est quin
cernat_: read Madvig's strong remarks on Goerenz's note here