On the other side of the path lies the abyss of tediously explaining too much. That offends because it impresses the hearers that you either do not respect their intelligence or are trying to blow a breeze into a tornado. Carefully estimate the probable knowledge of your audience, both in general and of the particular point you are explaining. In trying to simplify, it is fatal to "sillify." To explain more than is needed for the purposes of your argument or appeal is to waste energy all around. In your efforts to be explicit do not press exposition to the extent of dulness—the confines are not far distant and you may arrive before you know it.
Some Purposes of Exposition
From what has been said it ought to be clear that, primarily, exposition weaves a cord of understanding between you and your audience. It lays, furthermore, a foundation of fact on which to build later statements, arguments, and appeals. In scientific and purely "information" speeches exposition may exist by itself and for itself, as in a lecture on biology, or on psychology; but in the vast majority of cases it is used to accompany and prepare the way for the other forms of discourse.
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: