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

OPPOSITION OF PROPOSITIONS. 73
by fig. 4. (b) P may be a narrower class than S, and
fall entirely within it :
" Some Europeans are not
Frenchmen," represented by fig. 5. Although any
actual instance of an O proposition will be of the same
type as one of these examples (a) or (), the mere form
of the O proposition does not exclude fig. 3.
We see, therefore, that the proposition O, like E, tells
something of the whole predicate ;
"
for if some
S
"
falls
wholly outside P, P must fall wholly outside that part
at least of S.
6. A term is said to be distributed, when we know
merely from the form of the proposition in which it
occurs that it is applicable to every individual of the
class. Which terms, then, are known to be distributed
in the four propositional forms ?
(1) In A, the subject is distributed,
as the "all"
tells us. But we do not know whether the predicate is
taken in its whole extent (as in 5, fig. 2), or only in
part
of it
tributed. 1
(fig. i); hence the predicate
is not dis
(2) In E, both subject and predicate are known to
be distributed, for the proposition tells us ( 5, fig. 3)
that the whole of S is outside P, and therefore the
whole of P must be outside S.
(3) In I, the subject is not known to be distributed
as the word "some" tells us; and the predicate is not,
for the proposition does not tell us whether it is taken
in its whole extent (fig. 5) or in part only (fig. 4).
(4) In O the subject is not known to be distributed ;
but the predicate is so, for, as we saw ( 5 ad finem\
the proposition tells us that the whole of P must fall
1 The word "distributed" is always nothing but an abbreviation
of the phrase "known from the form of the proposition to be dis
tributed."