The Complete Aristotle (eng.)

censures them for awarding
distinctions to fine athletes but giving no prize for intellectual
ability. Or one may begin with a piece of advice, thus: ‘We ought
to honour good men and so I myself am praising Aristeides’ or ‘We
ought to honour those who are unpopular but not bad men, men whose
good qualities have never been noticed, like Alexander son of
Priam.’ Here the orator gives advice. Or we may begin as speakers
do in the law-courts; that is to say, with appeals to the audience
to excuse us if our speech is about something paradoxical,
difficult, or hackneyed; like Choerilus in the lines—
But now when allotment of all has been made…
    Introductions to speeches of display, then, may be composed of
some piece of praise or censure, of advice to do or not to do
something, or of appeals to the audience; and you must choose
between making these preliminary passages connected or disconnected
with the speech itself.
    Introductions to forensic speeches, it must be observed, have
the same value as the prologues of dramas and the introductions to
epic poems; the dithyrambic prelude resembling the introduction to
a speech of display, as
For thee, and thy gilts, and thy battle-spoils… .
    In prologues, and in epic poetry, a foretaste of the theme is
given, intended to inform the hearers of it in advance instead of
keeping their minds in suspense. Anything vague puzzles them: so
give them a grasp of the beginning, and they can hold fast to it
and follow the argument. So we find—
Sing, O goddess of song, of the Wrath…
Tell me, O Muse, of the hero…
Lead me to tell a new tale, how there came great warfare to
Europe
Out of the Asian land…
    The tragic poets, too, let us know the pivot of their play; if
not at the outset like Euripides, at least somewhere in the preface
to a speech like Sophocles—
Polybus was my father… ;
    and so in Comedy. 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.
    The other kinds of introduction employed are remedial in
purpose, and may be used in any type of speech. They are concerned
with the speaker, the hearer, the subject, or the speaker’s
opponent. Those concerned with the speaker himself or with his
opponent are directed to removing or exciting prejudice. But
whereas the defendant will begin by dealing with this sort of
thing, the prosecutor will take quite another line and deal with
such matters in the closing part of his speech. The reason for this
is not far to seek. The defendant, when he is going to bring
himself on the stage, must clear away any obstacles, and therefore
must begin by removing any prejudice felt against him. But if you
are to excite prejudice, you must do so at the close, so that the
judges may more easily remember what you have said.
    The appeal to the hearer aims at securing his goodwill, or at
arousing his resentment, or sometimes at gaining his serious
attention to the case, or even at distracting it-for gaining it is
not always an advantage, and speakers will often for that reason
try to make him laugh.
    You may use any means you choose to make your hearer receptive;
among others, giving him a good impression of your character, which
always helps to secure his attention. He will be ready to attend to
anything that touches himself and to anything that is important,
surprising, or agreeable; and you should accordingly convey to him
the impression that what you have to say is of this nature. If you
wish to distract his attention, you should imply that the subject
does not affect him, or is trivial or disagreeable. But observe,
all this has nothing to do with the speech itself. It merely has to
do with the weak-minded tendency of the hearer to listen to what is
beside the point. Where this tendency is absent, no introduction
wanted beyond a summary statement of your subject, to put a sort of
head on the main body of your speech. Moreover, calls for
attention, when required, may come equally well in any part of a
speech; in fact, the beginning of it is just where there is least
slackness of interest; it is therefore ridiculous to put this kind
of thing at the beginning, when every one is listening with most
attention. Choose therefore any point in the speech where such an
appeal is needed, and then say ‘Now I beg you to note this point-it
concerns you quite as much as myself’;