A finished oration is a work of art. Ancient rhetoricians distinguished six parts, which may still be found in some elaborate specimens of pulpit or forensic eloquence. These six parts were (1) the exordium or introduction, (2) the division of the subject, (3) the statement of what is to be established, (4) the argumentation, (5) the appeal to the feelings, and (6) the peroration or conclusion.
It is evident that this scheme for an oration is, as a rule, much too artificial and elaborate for use at the present day. Modern intelligence and modern intensity of life demand greater brevity and directness. An audience of the present time rarely has patience with a discourse of more than an hour, and it generally prefers one of half that length. In a modern discourse we may generally recognize a threefold division:
(1) The introduction, which points out the relation of the subject to the occasion, or otherwise prepares the audience better to appreciate the discussion that is to follow. It should be natural, and not so lengthy as to be out of keeping with the main body of the discourse.
(2) The discussion of the subject in hand. This consists of a statement of the theme and the various facts, arguments, and illustrations that are designed to throw light upon it and establish its truth. This is the main part of the discourse, and great care should be exercised in the statement of facts and the arrangement of arguments. Personal conviction should be back of what is said, for without this tone of sincerity the most brilliant rhetoric and eloquent declamation will be in vain.
(3) The conclusion, in which the results of the discussion are presented. It should be clear and claim no more than has been fairly established in the preceding discussion. On the basis of the truth previously presented it may contain an appeal to the feelings and the will, urging the course of action that has been shown to be advisable, wise, or obligatory.
Argumentation may seek to establish the truth of a proposition in four different ways:
(1) There may be the introduction of testimony. By testimony is meant the statements of actual observers or witnesses. It rests on experience, and may be given orally or in writing; hence we have oral and written testimony.
(2) A proposition may be supported or established by analogy. Reasoning from analogy is that process by which we infer that when two objects resemble each other in several known particulars they will also resemble each other in a certain unknown particular. The planet Mars, for example, resembles the earth in shape, motion, atmosphere, change of seasons, and relation to the sun; and from the resemblance in these known particulars some persons have inferred that, like the earth, it is also inhabited.
Analogical reasoning has a prominent place in our mental operations. Analogy lies at the basis of simile, metaphor, and personification, which are often used in argumentation. We frequently use analogical processes in the practical affairs of life, inferring, for example, that there will be rain to-day because the temperature, appearance of the clouds, and the condition of the atmosphere resemble those of a rainy day last week.