John C. Calhoun: Speech on The Force Bill, 1833
The example should be taken from the same phase of life as the proposition it explains. As Calhoun was discussing governmental regulation he supposed an example from majority rule. In the next the topic is copyright, so the illustration is not taken from patents. In introducing your own examples avoid the trite, amateurish expression "take, for instance."
Now, this is the sort of boon which my honorable and learned friend holds out to authors. Considered as a boon to them, it is a mere nullity; but, considered as an impost on the public, it is no nullity, but a very serious and pernicious reality. I will take an example. Dr. Johnson died fifty-six years ago. If the law were what my honorable and learned friend wishes to make it, somebody would now have the monopoly of Dr. Johnson's works. Who that somebody would be it is impossible to say; but we may venture to guess. I guess, then, that it would have been some bookseller, who was the assign of another bookseller, who was the grandson of a third bookseller, who had bought the copyright from Black Frank, the doctor's servant and residuary legatee, in 1785 or 1786. Now, would the knowledge that this copyright would exist in 1841 have been a source of gratification to Johnson? Would it have stimulated his exertions? Would it have once drawn him out of his bed before noon? Would it have once cheered him under a fit of the spleen? Would it have induced him to give us one more allegory, one more life of a poet, one more imitation of Juvenal? I firmly believe not. I firmly believe that a hundred years ago, when he was writing our debates for the Gentleman's Magazine, he would very much rather have had twopence to buy a plate of shin of beef at a cook's shop underground.
Thomas Babington Macaulay: Copyright, 1841
Comparison. Unfamiliar matter may be made plain by showing how it resembles something already clearly understood by the audience. This is comparison. It shows how two things are alike. The old geographies used to state that the earth is an oblate spheroid, then explain that term by comparison with an orange, pointing out the essential flattening at the poles. In any use of comparison the resemblance must be real, not assumed. Many a speaker has been severely criticized for his facts because he asserted in comparison similarities that did not exist.
Contrast. When the differences between two things are carefully enumerated the process is termed contrast. This is often used in combination with comparison, for no two things are exactly alike. They may resemble each other in nearly all respects, so comparison is possible and helpful up to a certain limit. To give an exact idea of the remainder the differences must be pointed out; that requires contrast.
In contrast the opposing balance of details does not have to depend necessarily on a standard familiar to the audience. It may be an arrangement of opposite aspects of the same thing to bring out more vividly the understanding. In his History of the English People, Green explains the character of Queen Elizabeth by showing the contrasted elements she inherited from her mother, Anne Boleyn, and her father, Henry VIII. Such a method results not only in added clearness, but also in emphasis. The plan may call for half a paragraph on one side, the second half on the other; or it may cover two paragraphs or sections; or it may alternate with every detail—an affirmative balanced by a negative, followed at once by another pair of affirmative and negative, or statement and contrast, and so on until the end. The speaker must consider such possibilities of contrast, plan for his own, and indicate it in his brief.
Nearly any speech will provide illustrations of the methods of comparison and contrast. Burke's Conciliation with America has several passages of each.
Cause to Effect. Explanations based on progressions from cause to effect and the reverse are admirably suited to operations, movements, changes, conditions, elections. An exposition of a manufacturing process might move from cause to effect. A legislator trying to secure the passage of a measure might explain its operation by beginning with the law (the cause) and tracing its results (the effect). So, too, a reformer might plead for a changed condition by following the same method. A speaker dealing with history or biography might use this same plan.