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

196
CHAPTER VII.
CONDITIONAL ARGUMENTS AND THE VALIDITY OF
THE SYLLOGISM.
i. ALL the syllogisms hitherto examined have consisted
of categorical propositions.
We have seen (ch.
III. i) that, in addition to cate
gorical propositions, there are conditional propositions
in which P is predicated of S under a condition. Of
these there are two kinds :
(a) Hypothetical or conjunctive :
(b) Disjunctive :
If S is P it is Q.
If S is P, Q is R.
S is either P or Q.
Either S is P or Q is R.
In a disjunctive proposition there may, of course, be
more than two alternatives. In a hypothetical proposi
tion the condition is introduced by
phrase
<?..,
"
if,"
or an equivalent
"
"
suppose that," granted or provided that,"
"allowing that," "whenever," "wherever."
The part of the hypothetical proposition which states
the condition or supposition is called the antecedent;
the other (the result of the opposition) is called the
consequent. The proposition is in fact an application