Dr "common" which are to be explained by more specific or individual truths or facts.

In exemplification, thus, a general principle of conduct is explained by the exhibition of a particular act in which it was manifested. The principle of patriotism is exemplified in the self-devotion of a Spartan hero; of justice in the stern decision of a Brutus; of christian heroism in the martyr at the stake.

General truths, also, are exemplified by some particular truth which they comprehend. That virtue is its own reward is exemplified, thus, in the elevated peace and happiness which follow a particular deed of self-denying benevolence. General facts, likewise, are exemplified in some particular instance. The circulation of the sap in vegetation is explained by an exhibition of it in a single plant.

§ 109. Exemplification readily combines with other processes in explanation without involving much liability to a loss of unity.

Perhaps the only liabilities to a violation of unity lie in the possibility of selecting an example which does not prop erly fall within the general truth to be explained; or in the multiplication of examples to such a degree as to hide from view the real truth to be explained.

§ 110. In the selection of examples, such as are most striking, most intelligible, most interesting to the hearer are ever to be preferred; since by such the object of speaking is best accomplished, which is to secure the clear and full understanding of the heme by the hearer.

§ 111. When the example has been selected and the general form in which it may be best introduced

to accomplish the object of the speaker has been determined, the actual exhibition of the example will be effected by some other process of explanation, as of narration, description or analysis. It will accordingly conform to the principles that control those processes.

CHAPTER VI.

OF COMPARISON AND CONTRAST.

§ 112. While in exemplification, a more generic truth or fact is explained by a more specific or an individual truth or fact embraced under it, in COMPARISON AND CONTRAST a truth or fact is explained by another of the same class.

If this process be investigated in its fundamental principles, it will be found that it necessarily rests on the idea of a similarity in things which may furnish a foundation for arranging them into classes. It presupposes, indeed, a class to which the themes compared or contrasted alike belong In comparison these points of resemblance are directly pre sented. In contrast, there must be a resemblance or simi larity in some respect or there can be no ground on which the contrast can rest. We cannot contrast an eruption of Vesuvius with the proposition that the angles of a triangle are equivalent to two right angles, because they cannot be arranged together under any class or any similarity between them of which use can be made in discourse.

This process differs, thus, from exemplification in the circumstance that while in the latter, the relation of the genus to the species or individual is involved, in the former there

is involved the relation of one individual or species to another through the class to which they both belong. The relation in the one case is single; in the other it is double.

Skill in the use of this process will, accordingly, depend chiefly on a clear and firm apprehension of the common class to which the things compared or contrasted alike be‐ long

§ 113. In comparison the theme is represented in the exhibition of those particulars in another of the same class which are common to the two; and the attention is directed to the points of resemblance.

In contrast the two objects of the same class are represented in the light of the opposition which in some respect they bear to each other.

The chief magistracy of a republic may be explained in comparison by an exhibition of the functions, relations and influences of the kingly office in unlimited monarchy, so far as they are common to both. It represents the nation; is the center of unity to them; is first among them; leads them; administers law for them, and the like. It may bɛ explained in contrast by the points of opposition. king in a pure monarchy is the end, and the state the means; the president in a republic is the means, the state the end. The one absorbs the state in himself; the other is absorbed in it. The one uses all the energies of the state for his own pleasure; the other uses his for the state.

The

Thus, also, truth and error may be compared as states of mind, occasioned and determined by similar causes, &c. They may be contrasted in their opposite natures and influ

ences.

§ 114. In comparison and contrast, the resemblance in the one case and the opposition in the other, may

+

lie in the constituent natures or properties of the objects compared or contrasted, or in the relations which they sustain. In the former case the process is denominated DIRECT or SIMPLE COMPARISON CONTRAST; in the latter case, it is denominated ANALOGICAL COMPARISON OF CONTRAST, or generally,

ANALOGY.

or

Virtue and vice are compared or contrasted directly when represented as moral states resembling or differing from each other in respect of their essential character or properties. As virtue, thus, implies intelligence and free choice, so also does vice. But as virtue consists in a regard paid to the principles of rectitude; vice consists in a disregard of them.

They are analogically compared or contrasted when exhibited in their relations to some third thing. Virtue is related to happiness as its appropriate and natural consequence; vice to misery.

§ 115. In the selection of the objects of comparison or of contrast, the same principles apply as in the case of exemplification, § 110. They should be striking, familiar, interesting.

Farther, in comparison, those objects of the same class should be selected which are most unlike the theme to be explained; while in contrast, it is conducive to clearness and effect to select those most resembling it.

The principle in the latter directions of this section is the same in the two cases. The mind, when there are but few points of resemblance, in comparison, or of opposition in contrast, is not disturbed and perplexed by many features crowding on the view.

§ 116. This process readily mingles in the same discourse with the other processes. It is commended by the same advantages generally that attend exemplification. It is sometimes the only convenient process of explanation.

§ 117. The subjects appropriate to this process are either generic or individual. The exhibition of the object with which the theme is compared or contrasted is effected by the processes before described.

CHAPTER VII.

OF THE INTRODUCTION AND PERORATION IN EX

PLANATORY DISCOURSE.

§ 118. THE EXPLANATORY INTRODUCTION § 68, will often be useful in this species of discourse for the purpose of bringing the theme more directly before the mind; or for facilitating the ready apprehension of the discussion itself.

In a history of Greece, it may be necessary in order to exhibit more distinctly to the reader of what people the history is to treat, to describe the country itself geographically, which the people inhabit. Such a geographical description, may, also, help the reader to understand the narrative itself. It may, moreover, explain the mode of constructing the history.

In a description of the virtue of "discretion," an explanatory introduction may usefully indicate the relation of this to other virtues, or exhibit an occasion of its exercise for