s nom. and not
abl. Petrus Valentia (p. 301, ed Orelli) justly remarks that an art is not
to be condemned as useless merely because it is unable to solve every
problem presented to it. He quotes Plato's remarks (in _Rep._ II.) that the
Expert is the man who knows exactly what his art can do and what it cannot.
Very similar arguments to this of Cic. occur in Sext., cf. esp. _P.H._ II.
175 and the words [Greek: eautou estai ekkalyptikon]. For the mode in which
Carneades dealt with Dialectic cf. Zeller 510, 511. The true ground of
attack is that Logic always _assumes_ the truth of phenomena, and cannot
_prove_ it. This was clearly seen by Aristotle alone of the ancients; see
Grote's essay on the Origin of Knowledge, now reprinted in Vol II. of his
_Aristotle_.

Sec.92. _Nata sit_: cf. 28, 59. _Loquendi_: the Stoic [Greek: logike], it must
be remembered, included [Greek: rhetorike]. _Concludendi_: [Greek: tou
symperainein] or [Greek: syllogizesthai]. _Locum_: [Greek: topon] in the
philosophical sense. _Vitiosum_: 49, n. _Num nostra culpa est_: cf. 32.
_Finium_: absolute limits; the fallacy of the _sorites_ and other such
sophisms lies entirely in the treatment of purely _relative_ terms as
though they were _absolute_. _Quatenus_: the same ellipse occurs in
_Orator_ 73. _In acervo tritici_: this is the false _sorites_, which may be
briefly described thus: A asks B whether one grain makes a heap, B answers
"No." A goes on asking whether two, three, four, etc. grains make a heap. B
cannot always reply "No." When he begins to answer "Yes," there will be a
difference of one grain between heap and no heap. One grain therefore
_does_ make a heap. The true _sorites_ or chain inference is still treated
in books on logic, cf. Thomson's _Laws of Thought_, pp 201--203, ed 8.
_Minutatim_: cf. Heindorf's note on [Greek: kata smikron] in _Sophistes_
217 D. _Interrogati_: cf. 104. In 94 we have _interroganti_, which some
edd. read here. _Dives pauper_, etc.: it will be easily seen that the
process of questioning above described can be applied to any relative term
such as these are. For the omission of any connecting particle between the
members of each pair, cf. 29, 125, _T.D._ I. 64, V. 73, 114, Zumpt _Gram._
782. _Quanto addito aut dempto_: after this there is a strange ellipse of
some such words as _id efficiatur, quod interrogatur_. [_Non_] _habemus_: I
bracket _non_ in deference to Halm, Madv. however (_Opusc._ I. 508) treats
it as a s