While there are almost countless methods of arrangements—­for any one used in one part of a speech may be combined with any other in some different portion—­the plan should always be determined by three fundamental matters; the material itself, the audience to which it is to be presented, and the effect the speaker wants to produce.

Even during this preliminary planning of the speech the author must be careful that when his arrangement is decided upon it possesses the three qualities necessary to every good composition.  These three are unity, coherence, and emphasis.

Unity.  Unity explains itself.  A speech must be about one single thing.  A good speech produces one result.  It induces action upon one single point.  It allows no turning aside from its main theme.  It does not stray from the straight and narrow road to pick flowers in the adjacent fields, no matter how enticing the temptation to loiter may be.  In plain terms it does not admit as part of its material anything not closely and plainly connected with it.  It does not step aside for everything that crops into the speaker’s mind.  It advances steadily, even when not rapidly.  It does not “back water.”  It goes somewhere.

To preserve unity of impression a speaker must ruthlessly discard all material except that which is closely associated with his central intention.  He must use only that which contributes to his purpose.  The same temptation to keep unrelated material—­if it be good in itself—­will be felt now as when the other unsuitable material was set aside.

This does not prevent variety and relief.  Illustrative and interesting minor sections may be, at times must be, introduced.  But even by their vividness and attractiveness they must help the speech, not hinder it.  The decorations and ornaments must never be allowed to detract from the utility of the composition.

Unity may be damaged by admitting parts not in the direct line of the theme.  It may be violated by letting minor portions become too long.  The illustration may grow so large by the introduction of needless details that it makes the listeners forget the point it was designed to enforce.  Or it may be so far-fetched as to bear no real relation to the thread of development.  Here lies the pitfall of the overworked “funny,” story, introduced by “that reminds me.”  Too often it is not humorous enough to justify repetition; or—­what is worse—­it does not fit into the circumstances.  Another fault of many speakers is over-elaboration of expression, not only for non-essentials, but in the important passages as well.  Involved language demands explanation.  The attempts to clear up what should have been simply said at first may lead a speaker to devote too many words to a single point.