A System of Logic, Ratiocinative and Inductive — John Stuart Mill — John Shaqi
A System of Logic, Ratiocinative and Inductive
John Stuart Mill · en
When the name which is the subject of the proposition is a general name,
we may intend to affirm or deny the predicate, either of all the things
that the subject denotes, or only of some. When the predicate is affirmed
or denied of all and each of the things denoted by the subject, the
proposition is universal; when of some undefined portion of them only, it
is particular. Thus, All men are mortal; Every man is mortal; are
universal propositions. No man is immortal, is also a universal
proposition, since the predicate, immortal, is denied of each and every
individual denoted by the term man; the negative proposition being exactly
equivalent to the following, Every man is not-immortal. But “some men are
wise,” “some men are not wise,” are particular propositions; the predicate
_wise_ being in the one case affirmed and in the other denied not of each
and every individual denoted by the term man, but only of each and every
one of some portion of those individuals, without specifying what portion;
for if this were specified, the proposition would be changed either into a
singular proposition, or into a universal proposition with a different
subject; as, for instance, “all _properly instructed_ men are wise.” There
are other forms of particular propositions; as, “_Most_ men are
imperfectly educated:” it being immaterial how large a portion of the
subject the predicate is asserted of, as long as it is left uncertain how
that portion is to be distinguished from the rest.(27)
When the form of the expression does not clearly show whether the general
name which is the subject of the proposition is meant to stand for all the
individuals denoted by it, or only for some of them, the proposition is,
by some logicians, called Indefinite; but this, as Archbishop Whately
observes, is a solecism, of the same nature as that committed by some
grammarians when in their list of genders they enumerate the _doubtful_
gender. The speaker must mean to assert the proposition either as a
universal or as a particular proposition, though he has failed to declare
which: and it often happens that though the words do not show which of the
two he intends, the context, or the custom of speech, supplies the
deficiency. Thus, when it is affirmed that “Man is mortal,” nobody doubts
that the assertion is intended of all human beings; and the word
indicative of universality is commonly omitted, only because the meaning
is evident without it. In the proposition, “Wine is good,” it is
understood with equal readiness, though for somewhat different reasons,
that the assertion is not intended to be universal, but particular.(28) As
is observed by Professor Bain,(29) the chief examples of Indefinite
propositions occur “with names of material, which are the subjects
sometimes of universal, and at other times of particular predication.
‘Food is chemically constituted by carbon, oxygen, etc.,’ is a proposition
of universal quantity; the meaning is all food—all kinds of food. ‘Food is