they should usually be presented in their chronological order, and there
should be a perceptible and often a rapid movement toward a definite
end. In all artistic narration we find unity, proportion, and
completeness. The following extract from Addison's "Vision of Mirza"
will serve for illustration: "On the fifth day of the moon--which,
according to the custom of my forefathers, I always keep holy--after
having washed myself and offered up my morning devotions, I ascended the
high hills of Bagdat, in order to pass the rest of the day in
meditation and prayer. As I was here airing myself on the tops of the
mountains, I fell into a profound contemplation on the vanity of human
life; and, passing from one thought to another, 'Surely,' said I, 'man
is but a shadow, and life a dream.'"

(3) _Exposition_ explains the nature or meaning of things. The purpose
of description is to form a picture; of narration, to portray an event;
of exposition, to set forth the distinctive nature of an object or
conception. The methods of exposition are various. In the first place,
the distinguishing features of an object may be presented; and in this
case exposition partakes of the nature of description. In the second
place, an object or idea may be explained by pointing out its effects;
and in this case exposition partakes of the character of narration. In
the third place, we may explain or define an object or conception by
indicating its resemblance or its unlikeness to something else that is
known. But whatever method of exposition is adopted, it should be full
and definite enough to impart a clear idea of the thing explained. Every
text-book will furnish examples of exposition; the following is taken
from Hitchcock's "Geology": "A _volcano_ is an opening in the earth from
whence matter has been ejected by heat, in the form of lava, scoria, or
ashes. Usually the opening called the _crater_ is an inverted cone; and
around it there rises a mountain in the form of a cone, with its apex
truncated, produced by the elevation of the earth's crust and the
ejection of lava."

(4) _Argumentation_ is the process of establishing the truth or falsity
of a thing. The means it uses is called proof or evidence, and will be
considered more fully in a subsequent chapter treating of oratory. This
proof or evidence may be derived from principles originating in the
mind, in which case it is called _intuitive_; or it may be found in
external sources, in whic