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.
"A speech must be about one single thing. "
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."
"Unity may be damaged by admitting parts not in the direct line of the theme."
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.
This matter of unity must not be misunderstood as prohibiting the inclusion of more than one topic in a speech. A legislator in urging the repeal of a law might have several topics, such as how the law was passed, its first operations, its increasing burdens upon people, the disappearance of the necessity for it, better methods of securing the same or better results, etc., yet all grouped about the motivating theme of securing the repeal of the law. To emphasize the greatness of a man's career a speaker might introduce such topics as his obscure origin, his unmarked youth, the spur that stimulated his ambition, his early reverses, provided that they contribute to the impression intended, to make vivid his real achievements.
"In early attempts at delivering speeches don't be afraid to pause at certain places to consider whether what you are about to say really contributes to the unity or destroys it."
In early attempts at delivering speeches don't be afraid to pause at certain places to consider whether what you are about to say really contributes to the unity or destroys it. Aside from helping you to think upon your feet, this mental exercise will help your speech by making you pause at times—a feature of speaking often entirely disregarded by many persons.