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

66 THE LOGICAL PROPOSITION.
(a] To have fine feathers
(b] the sign of being a fine bird ;
(c] denied of some instances of the subject.
"To have fine feathers is sometimes not the
Hence SoP,
a fine bird."
sign of being
"
(i i) Some of the English kings have been worthless."
In order to deal with propositions referring to past time,
some logicians propose to turn them into propositions of
" Some English kings are in the class
classification, thus :
constituted by the attribute of worthlessness at the given
time." But it is not necessary to be so very cumbrous. It
is true that "every act of judgment is a present
one and
expresses a present belief." But in a proposition referring
to past or future time, the truth of the proposition lies in its
reference to that point of time ; and we may express the
meaning formally by putting ourselves at that point of time,
and therefore using a proposition whose copula is in the
" Some English kings are worthless." Simi
present tense :
larly, "all had fled" may be expressed, "all are persons
who have fled."
(12)
"
Half of his answers are wrong."
Here, if
"
half" is merely indefinite and means "a good
many," the proposition is obviously SiP. If we take it as
it has to be treated
a numerical statement, strictly definite,
as a compound proposition, and part of the meaning sacri
ficed by analysing it into a pair of I propositions,
( (a) Some of his answers are wrong.
( (b] Some of his answers are not-wrong. 1
But definite numerical statements cannot be fully dealt
with in elementary Logic. Finding the formal expression
of propositions like those given in examples u and 12 is an
unprofitable puzzle, for we do not succeed in expressing all
their meaning.
1
It is worth noting that the phrase "half of his answers" is not
so precise as it looks. It is only abstractly precise.
If it meant
"
this half" it would be really precise, and would be a singular (an
A) proposition.