An introductory text-book of logic - Mellone, Sydney - Rare Books at ...

164
MEDIATE INFERENCE.
NOTE.
When we know whether the Subject and the Predicate of
a proposition are distributed or undistributed, we know both
the quantity and quality of the proposition (ch. III. 6).
Hence if we indicate a distributed term by the mark - and
an undistributed term by the mark w the four forms of the
proposition may be expressed thus :
universal affirmative S P
ii negative S P
particular
affirmative S P
ii negative S P
Hence all the moods of the syllogism may be expressed
without using any other symbols than those indicating the
distribution or non-distribution of the terms :
Barbara
Festino J
SM ISM
SP SP
Darapti -[ _ Disarms |
MS IMS
SP SP
This notation has the advantage of showing at a glance the
validity (or invalidity) of the syllogism according to the
rules regarding the distribution of terms (ch. V. 3), and
of showing whether the mood is formally "strengthened"
or not (ch. V. 8), as is Darapti when compared with
Disamis.