Aristotle, and W. Rhys Roberts. Rhetoric. Mineola, NY: Dover, 2004. Kindle Electronic Edition.
Book III, chapter 14.
Aristotle comments on the similarity of the starts of different works of art (Aristotle III.14, B. 1414b). In a speech of display, the introduction is normally a “piece of praise or censure” (Aristotle III.14, B. 1415a). In a forensic speech, on the other hand, the prologue introduces the theme of the speech, rather than creating suspense (Aristotle III.14, B. 1415a). “This, then, is the most essential function and distinctive property of the introduction, to show what the aim of the speech is; and therefore no introduction ought to be employed where the subject is not long or intricate” (Aristotle III.14, B. 1415a). Aristotle reminds his reader that many different means may be appropriate to secure the agreement of the hearer (Aristotle III.14, B. 1415b). Yet since long introductions are normally used by those with weak cases, he recommends keeping the introduction relatively short (Aristotle III.14, B. 1415b).