uage may be acquired; nor are they
the only means by which the acquisition of such knowledge may be aided. To
exhibit or point out _things_ and tell their names, constitutes a large
part of that instruction by which the meaning of words is conveyed to the
young mind; and, in many cases, a mere change or apposition of terms may
sufficiently explain our idea. But when we would guard against the
possibility of misapprehension, and show precisely what is meant by a word,
we must fairly define it. There are, however, in every language, many words
which do not admit of a formal definition. The import of all definitive and
connecting particles must be learned from usage, translation, or
derivation; and nature reserves to herself the power of explaining the
objects of our simple original perceptions. "All words standing for complex
ideas are definable; but those by which we denote simple ideas, are not.
For the perceptions of this latter class, having no other entrance into the
mind, than by sensation or reflection, can be acquired only by
experience."--_Duncan's Logic_, p. 63. "And thus we see, that as our simple
ideas are the materials and foundation of knowledge, so the names of simple
ideas may be considered as the elementary parts of language, beyond which
we cannot trace the meaning and signification of words. When we come to
them, we suppose the ideas for which they stand to be already known; or, if
they are not, experience alone must be consulted, and not definitions or
explications."--_Ibid._, p. 69.

19. But this is no apology for the defectiveness of any definition which
might be made correct, or for the effectiveness of our English grammars, in
the frequent omission of all explanation, and the more frequent adoption of
some indirect form of expression. It is often much easier to make some
loose observation upon what is meant by a given word or term in science,
than to frame a faultless definition of the thing; because it is easier to
refer to some of the relations, qualities, offices, or attributes of
things, than to discern wherein their essence consists, so as to be able to
tell directly and clearly what they are. The improvement of our grammatical
code in this respect, was one of the principal objects which I thought it
needful to attempt, when I first took up the pen as a grammarian. I cannot
pretend to have seen, of course, every definition and rule which has been
published on this subject; but, if I do not misju