M. Barthélemy St. Hilaire (in the note to his translation, p. 14)
does not lend any additional clearness, when he talks of the
"_conclusion_" from the propositions A and E in the First figure.
Julius Pacius says (p. 134): "Si tamen _conclusio_ dici debet, quæ
non colligitur ex propositionibus," &c. Moreover, M. St. Hilaire (p.
19) slurs over the legitimate foundation, the appeal to experience,
much as Aristotle himself does: "Puis prenant des exemples où la
_conclusion est de toute évidence_, Aristote les applique
successivement à chacune de ces combinaisons; celles qui donnent la
_conclusion fournie d'ailleurs par le bon sens_, sont concluantes ou
syllogistiques, les autres sont asyllogistiques."]
We are now introduced to the Second figure, in which each of the two
premisses has the middle term as Predicate.[29] To give a legitimate
conclusion in this figure, one or other of the premisses must be
negative, and the major premiss must be universal; moreover no
affirmative conclusions can ever be obtained in it--none but negative
conclusions, universal or particular. In this Second figure too,
Aristotle recognizes four valid modes; setting aside the other
possible modes as invalid[30] (in the same way as he had done in the
First figure), because the third proposition or conjunction of the
major term with the minor, might in some cases be a true universal
affirmative, in other cases a true universal negative. As to the
third and fourth of the valid modes, he demonstrates them by assuming
the contradictory of the conclusion, together with the major premiss,
and then showing that these two premisses form a new syllogism, which
leads to a conclusion contradicting the minor premiss. This method,
called _Reductio ad Impossibile_, is here employed for the first
time; and employed without being ushered in or defined, as if it were
familiarly known.[31]
[Footnote 29: Analyt. Prior. I. v. p. 26, b. 34. As Aristotle
enunciates a proposition by putting the predicate before the subject,
he says that in this Second figure the middle term comes [Greek:
prô=ton tê=| the/sei]. In the Third figure, for the same reason, he
calls it [Greek: e)/schaton tê=| the/sei], vi. p. 28, a. 15.]
[Footnote 30: Analyt. Prior. I. v. p. 27, a. 18. In these invalid
modes, Aristotle says there is no _syllogism_; therefore we cannot
properly speak of a _conclusion_, but only of a third proposition,
conjoining the major with the minor.]
[Footnote 31: Ibid. p. 27, a. 15, 26, seq. It is said to involve
[Greek: u(po/thesis], p. 28, a. 7; to be [Greek: e)x u(pothe/seôs]
xxiii. p. 41, a. 25; to be [Greek: tou= e)x u(pothe/seôs], as opposed
to [Greek: deiktiko/s], xxiii. p. 40, b. 25.
M. B. St. Hilaire remarks justly, that Aristotle might be expected to
define or explain what it is, on first mentioning it (note, p. 22).]