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

AND THE ARISTOTELIAN SYLLOGISM. 121
We have here three A propositions ;
hence this form
of syllogism is referred to as AAA. As we shall see,
this is the only way in which an A proposition can be
syllogistically proved. We shall denote the syllogism
thus :
MaP,
SaM;
/.SaP.
As already indicated, MaP, SaM, are the premises, and
SaP the conclusion. We shall (apart from an occasional
exceptional case) always use S to denote the subjectterm
of the conclusion (hence also the matter about
which the conclusion is to be proved) ; and, for clear
ness, we shall draw a line between the premises and
the conclusion. The term M, which is common to
the two premises, is called the middle term (TO /j,ecrov,
the mean). For one reason, it is the means by which
the two propositions are connected, or the other two
terms compared. The other two terms, S and P, are
the extremes (a/cpa). Comparing
the extent of the terms S, M, P,
in our given syllogism AAA, we
see that the extent of S is less
than that of M, and the extent
of M less than that of P ;
for the
argument states that S is in M,
and M in P. Hence in the syllo
gism AAA, S is called the minor
term (TO eXarrov, TO eo-^arov},
and P the major term (TO fjuelfrv, TO Trpcorov) ; and we
have another reason for calling M the
"
"
middle term. 1
1 The case, which might occur in the syllogism AAA. of two or
all of the terms S, M, P, being co-extensive, is set aside, for the
purposes of this definition.
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