he various ways along which a speaker may proceed in exposition are
likely to touch each other now and then, and even when they do not meet
and actually overlap they run so nearly parallel that the roads are
sometimes distinct rather in theory than in any more practical respect.

=Definition=, the primary expository method, is a statement of precise
limits.[15] Obviously, here the greatest care must be exercised that the
terms of definition should not themselves demand too much definition;
that the language should be concise and clear; and that the definition
should neither exclude nor include too much. The following is a simple
example:

To expound is to set forth the nature, the significance, the
characteristics, and the bearing of an idea or a group of ideas.

--ARLO BATES, _Talks on Writing English_.

=Contrast and Antithesis= are often used effectively to amplify
definition, as in this sentence, which immediately follows the
above-cited definition:

Exposition therefore differs from Description in that it deals
directly with the meaning or intent of its subject instead of
with its appearance.

This antithesis forms an expansion of the definition, and as such it
might have been still further extended. In fact, this is a frequent
practise in public speech, where the minds of the hearers often ask for
reiteration and expanded statement to help them grasp a subject in its
several aspects. This is the very heart of exposition--to amplify and
clarify all the terms by which a matter is defined.

=Example= is another method of amplifying a definition or of expounding
an idea more fully. The following sentences immediately succeed Mr.
Bates's definition and contrast just quoted:

A good deal which we are accustomed inexactly to call
description is really exposition. Suppose that your small boy
wishes to know how an engine works, and should say: "Please
describe the steam-engine to me." If you insist on taking his
words literally--and are willing to run the risk of his
indignation at being wilfully misunderstood--you will to the
best of your ability picture to him this familiarly wonderful
machine. If you explain it to him, you are not describing but
expounding it.

The chief value of example is that it makes clear the unknown by
referring the mind to the known. Readiness of mind to make illuminating,
apt comparisons for the sake of clearness is one of th