Third, by Details. Third, a common way of explaining a proposition is to go into particulars about it. Enough particulars should be given to furnish a reasonable explanation of the proposition. Macaulay, writing of the “muster-rolls of names” which Milton uses, goes into details. He says:—
“They are charmed names. Every one of them is the first link in a long chain of associated ideas. Like the dwelling place of our infancy revisited in manhood, like the song of our country heard in a strange land, they produce upon us an effect wholly independent of their intrinsic value. One transports us back to a remote period of history. Another places us among the novel scenes and manners of a distant region. A third evokes all the dear classical recollections of [97] childhood,—the schoolroom, the dog-eared Virgil, the holiday, and the prize. A fourth brings before us the splendid phantoms of chivalrous romance, the trophied lists, the embroidered housings, the quaint devices, the haunted forests, the enchanted gardens, the achievements of enamoured knights, and the smiles of rescued princesses.”[16]
Fourth, by Illustrations. Fourth, a proposition may be explained by the use of a single example or illustration. The value of this method depends on the choice of the example. It must in no essential way differ from the general case it is intended to illustrate. Supposing this proposition were advanced by some woman-hater: “All women are, by nature, liars,” and it should be followed by this sentence, “For example, take this lady of fashion.” Such an illustration is worthless. The individual chosen does not fairly represent the class. If, on the other hand, a teacher in physics should announce that “all bodies fall at the same rate in a vacuum,” and should illustrate by saying, “If I place a bullet and a feather in a tube from which the air has been exhausted, they will be found to fall equally fast,” his example would be a fair one, as the two objects differ in no manner essential to the experiment from “all bodies.”
Here should be included anecdotes used as illustrations. They are of value if they are of the same type as the general class they are intended to explain. They may be of little value, however. It could safely be said that half the stories told in campaign speeches are not instances in point at all, but are told only to amuse and deceive. Specific instances must be chosen with care if they are to serve a useful purpose in exposition.
This example is from Newman:—
“To know is one thing, to do is another; the two things [98] are altogether distinct. A man knows that he should get up in the morning,—he lies abed; he knows that he should not lose his temper, yet he cannot keep it. A laboring man knows that he should not go to the ale-house, and his wife knows that she should not filch when she goes out charing, but, nevertheless, in these cases, the consciousness of a duty is not all one with the performance of it. There are, then, large families of instances, to say the least, in which men may become wiser, without becoming better.”[17]
Fifth, by Comparisons. Last, a thing may be explained by telling what it is like, or what it is not like. This method of comparison is very frequently employed. To liken a thing to something already known is a vivid way of explaining. Moreover in many cases it is easier than the method of repetition or that of details. By this method Macaulay explains his proposition that “it is the character of such revolutions that we always see the worst of them first.” He says:—
“A newly liberated people may be compared to a northern army encamped on the Rhine or the Xeres. It is said that when soldiers in such a situation first find themselves able to indulge without restraint in such a rare and expensive luxury, nothing is to be seen but intoxication. Soon, however, plenty teaches discretion, and, after wine has been for a few months their daily fare, they become more temperate than they had ever been in their own country. In the same manner, the final and permanent fruits of liberty are wisdom, moderation, and mercy. Its immediate effects are often atrocious crimes, conflicting errors, skepticism on points the most clear, dogmatism on points the most mysterious.”[18]
The comparison may be a simile or a metaphor, as when Huxley writes, explaining “the physical basis of life:”—
“Protoplasm, simple or nucleated, is the formal basis of all life. It is the clay of the potter: which, bake it and [99] paint it as he will, remains clay, separated by artifice, and not by nature, from the commonest brick or sun-dried clod.”[19]