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

IMPORT OF PROPOSITIONS AND JUDGMENTS. 105
The term which is larger
in extension is smaller in
comprehension, and vice versa ; hence the copula is has
"
two meanings. For instance, the proposition Man is
fallible," read in extension, means that the class man is
included in the class fallible beings ; read in compre
hension, it means that the complex concept man in
cludes as part of itself the attribute of fallibility. The
former of the two interpretations is of course the class
view with which we are familiar. The latter, known
as the
"
"
comprehensive
view of the proposition, re
quires careful consideration.
We have found it necessary to assume that the in
tension of any term is relatively fixed (ch. II. 7) ;
expressed in the Definition of the term, giving
analytic proposition (ch.
it is
us an
III. 2). The "compre
hensive view," if taken strictly and without qualification,
applies only to propositions where the predicate states
the meaning or part of the meaning of the subject-term.
In any proposition which gives us information about a
subject, the idea of the predicate is not simply con
tained in the idea of the subject. 1
Hamilton s doctrine of the Quantification of the
Predicate is a development of the class view of the
proposition, but it is an inconsistent development.
He adopts the four forms A, E, I, O, which depend
on the predicative view, and then doubles them by
attaching "some" and "all" to the predicate. This
is to abandon the predicative view and treat the
predicate as a class ; and if we do this (see 2) we
do not get eight forms of the proposition but only
1 Nevertheless the point which Hamilton raises is a very import
ant one ; further consideration of its philosophical aspects will be
found in ch. XI. 8 i.