The duty of the Arguments is to attempt demonstrative proofs.
These proofs must bear directly upon the question in dispute, which must fall under one of four heads. (1) If you maintain that the act was not committed, your main task in court is to prove this. (2) If you maintain that the act did no harm, prove this. If you maintain that (3) the act was less than is alleged, or (4) justified, prove these facts, just as you would prove the act not to have been committed if you were maintaining that.
It should be noted that only where the question in dispute falls under the first of these heads can it be true that one of the two parties is necessarily a rogue. Here ignorance cannot be pleaded, as it might if the dispute were whether the act was justified or not.
This argument must therefore be used in this case only, not in the others.
In ceremonial speeches you will develop your case mainly by arguing that what has been done is, e.g., noble and useful. The facts themselves are to be taken on trust; proof of them is only submitted on those rare occasions when they are not easily credible or when they have been set down to some one else.
In political speeches you may maintain that a proposal is impracticable; or that, though practicable, it is unjust, or will do no good, or is not so important as its proposer thinks. Note any falsehoods about irrelevant matters-they will look like proof that his other statements also are false. Argument by 'example' is highly suitable for political oratory, argument by 'enthymeme' better suits forensic. Political oratory deals with future events, of which it can do no more than quote past events as examples. Forensic oratory deals with what is or is not now true, which can better be demonstrated, because not contingent-there is no contingency in what has now already happened. Do not use a continuous succession of enthymemes: intersperse them with other matter, or they will spoil one another's effect. There are limits to their number-Friend, you have spoken as much as a sensible man would have spoken.
,as much' says Homer, not 'as well'. Nor should you try to make enthymemes on every point; if you do, you will be acting just like some students of philosophy, whose conclusions are more familiar and believable than the premisses from which they draw them. And avoid the enthymeme form when you are trying to rouse feeling; for it will either kill the feeling or will itself fall flat: all simultaneous motions tend to cancel each other either completely or partially.
Nor should you go after the enthymeme form in a passage where you are depicting character-the process of demonstration can express neither moral character nor moral purpose. Maxims should be employed in the Arguments-and in the Narration too-since these do express character: 'I have given him this, though I am quite aware that one should "Trust no man".' Or if you are appealing to the emotions: 'I do not regret it, though I have been wronged; if he has the profit on his side, I have justice on mine.'