If an author is writing for other purposes than for conscious
practice, he should choose the form of discourse in which he can best
work, and to which he can best shape his material. Some men tell
stories well; others are debaters; while yet others are wonderfully
gifted with eloquence. Emerson understood life thoroughly. He knew
man's feelings, his motives, his hopes, his strength, his weakness;
yet one cannot imagine Emerson shaping this material into a novel. But
just a little way down the road lived a wizard who could transmute the
commonest events of this workaday world to the most beautiful shapes;
no one wishes that Hawthorne had written essays. The second principle
guiding in the choice of a subject is this: _Select a subject which is
suited to your peculiar ability as an author._

Knowledge of Subject.

The form, then, should suit the matter; and it should be the form in
which the author can work. There is a third principle that should
guide in the choice of a subject. _It should be a subject of which the
author knows something._ Pupils often exclaim, "What can I write
about!" as if they were expected to find something new to write. An
exercise in composition has not for its object the proclaiming of any
new and unheard-of thing; it is an exercise in the expression of
things already known. Even when the subject is known, the treatment
offers difficulties enough. It is not true that what is thoroughly
understood is easily explained. Many excellent scholars have written
very poor text-books because they had not learned the art of
expression. A necessary antecedent of all good composition is a full
and accurate knowledge of the subject; and even when one knows all
about it, the clear expression of the thought will be difficult
enough.

To demand accurate knowledge of the subject before an author begins
work upon it narrows the field from which themes may be drawn.
Burroughs is an authority on all the tenants of our groves;
"Wake-Robin," "Pepacton," and his other books all show a master's
certain hand. So Stedman is an authority in matters relating to
literature. But Burroughs and Stedman alike would find difficulty in
writing an essay on "Electricity in the Treatment of Nervous
Diseases." They do not know about it. A boy in school probably knows
something of fishing; of this he can write. A girl can tell of "The
Last Parlor Concert." Both could write very entertainingly of their
"First Algebra Recitation