jectives may well
be substituted for the articles; but _not generally_. If the articles were
generally equivalent to adjectives, or even if they were generally _like_
them, they would _be_ adjectives; but, that adjectives may occasionally
supply their places, is no argument at all for confounding the two parts of
speech. Distinctions must be made, where differences exist; and, that _a,
an_, and _the_, do differ considerably from the other words which they most
resemble, is shown even by some who judge "the distinctive name of
_article_ to be useless." See _Crombie's Treatise_, Chap. 2. The articles
therefore must be distinguished, not only from adjectives, but from each
other. For, though both are _articles_, each is an index _sui generis_; the
one definite, the other indefinite. And as the words _that_ and _one_
cannot often be interchanged without a difference of meaning, so the
definite article and the indefinite are seldom, if ever, interchangeable.
To put one for the other, is therefore, in general, to put one _meaning_
for an other: "_A_ daughter of _a_ poor man"--"_The_ daughter of _the_ poor
man"--"_A_ daughter of _the_ poor man"--and, "_The_ daughter of _a_ poor
man," are four phrases which certainly have four different and distinct
significations. This difference between the two articles may be further
illustrated by the following example: "That Jesus was _a_ prophet sent from
God, is one proposition; that Jesus was _the_ prophet, _the_ Messiah, is an
other; and, though he certainly was both _a_ prophet and _the_ prophet, yet
_the_ foundations of _the_ proof of these propositions are separate and
distinct."--_Watson's Apology_, p. 105.

OBS. 4.--Common nouns are, for the most part, names of large classes of
objects; and, though what really constitutes the species must always be
found entire in every individual, the several objects thus arranged under
one general name or idea, are in most instances susceptible of such a
numerical distribution as gives rise to an other form of the noun,
expressive of plurality; as, _horse, horses_. Proper nouns in their
ordinary application, are, for the most part, names of particular
individuals; and as there is no plurality to a particular idea, or to an
individual person or thing as distinguished from all others, so there is in
general none to this class of nouns; and no room for _further restriction
by articles_. But we sometimes divert such nouns from their usual
significati