Clearness, precision, accuracy, unity, truth, and necessity--these must be the constant standards by which you test the efficiency of your expositions, and, indeed, that of every explanatory statement. This dictum should be written on your brain in letters most plain. And let this apply not alone to the purposes of exposition but in equal measure to your use of the
Methods of Exposition
The various ways along which a speaker may proceed in exposition are likely to touch each other now and then, and even when they do not meet and actually overlap they run so nearly parallel that the roads are sometimes distinct rather in theory than in any more practical respect.
=Definition=, the primary expository method, is a statement of precise limits.[15] Obviously, here the greatest care must be exercised that the terms of definition should not themselves demand too much definition; that the language should be concise and clear; and that the definition should neither exclude nor include too much. The following is a simple example:
To expound is to set forth the nature, the significance, the characteristics, and the bearing of an idea or a group of ideas.
--ARLO BATES, Talks on Writing English.
=Contrast and Antithesis= are often used effectively to amplify definition, as in this sentence, which immediately follows the above-cited definition:
Exposition therefore differs from Description in that it deals directly with the meaning or intent of its subject instead of with its appearance.
This antithesis forms an expansion of the definition, and as such it might have been still further extended. In fact, this is a frequent practise in public speech, where the minds of the hearers often ask for reiteration and expanded statement to help them grasp a subject in its several aspects. This is the very heart of exposition--to amplify and clarify all the terms by which a matter is defined.
=Example= is another method of amplifying a definition or of expounding an idea more fully. The following sentences immediately succeed Mr. Bates's definition and contrast just quoted:
A good deal which we are accustomed inexactly to call description is really exposition. Suppose that your small boy wishes to know how an engine works, and should say: "Please describe the steam-engine to me." If you insist on taking his words literally--and are willing to run the risk of his indignation at being wilfully misunderstood--you will to the best of your ability picture to him this familiarly wonderful machine. If you explain it to him, you are not describing but expounding it.
The chief value of example is that it makes clear the unknown by referring the mind to the known. Readiness of mind to make illuminating, apt comparisons for the sake of clearness is one of the speaker's chief resources on the platform--it is the greatest of all teaching gifts. It is a gift, moreover, that responds to cultivation. Read the three extracts from Arlo Bates as their author delivered them, as one passage, and see how they melt into one, each part supplementing the other most helpfully.
=Analogy=, which calls attention to similar relationships in objects not otherwise similar, is one of the most useful methods of exposition. The following striking specimen is from Beecher's Liverpool speech:
A savage is a man of one story, and that one story a cellar. When a man begins to be civilized he raises another story. When you christianize and civilize the man, you put story upon story, for you develop faculty after faculty; and you have to supply every story with your productions.
=Discarding= is a less common form of platform explanation. It consists in clearing away associated ideas so that the attention may be centered on the main thought to be discussed. Really, it is a negative factor in exposition though a most important one, for it is fundamental to the consideration of an intricately related matter that subordinate and side questions should be set aside in order to bring out the main issue. Here is an example of the method:
