Institutio Oratoria

Tile term enthymeme [*](For this chapter see note prefixed to Index.) is applied not merely to the actual argument, that is to say, the matter adduced to prove something else, but also to its expression, the nature of which, as I have already pointed out, is twofold. [*](cp. v. x. 2. ) It may be drawn from denial of consequents, when it will consist of a proposition immediately followed by a proof, as in the following passage from the pro Ligario; [*]( vi. 19. The cause helped by heaven is that of Caesar. cp. Lucan's victrix causa deis placuit, sed victa Catoni. )

At that point the justice of the cause was doubtful, since there was something to be said on both sides. But now we can only regard that cause as superior, which even the gods supported.

Here we have a proposition and a reason, but no formal conclusion: it is therefore tile incomplete syllogism known as an enthymeme.

It may on the other hand be drawn from incompatibles, in which case the proof will be much stronger; indeed some restrict the title of enthymeme [*](cp. v. x. 2. ) to this form of argument. The following passage from the pro Milone [*](xxix. 79. The death is that of Clodius.) of Cicero will provide a parallel:

You are then sitting there to avenge the death of a man whom you would refuse to restore to life, even if you thought it within your power to do so.

This form of argument may even at times consist of a number of clauses, as in the following passage from the same speech [*](xvi. 41.) :

Was he resolved then to kill to the dissatisfaction of some a man whom he refused to kill to the satisfaction of all? Are we to believe that he did not hesitate, in defiance of the law and

v4-6 p.351

despite the unfavourable circumstances both of time and place and the risk involved to his own life, to kill one whom he did not venture to kill when he might have done so legally, at his own time and place and without the least danger to himself?

The most effective kind of enthymeme seems however to be that in which a reason is subjoined to a dissimilar or contrary proposition as in the following passage from Demosthenes [*](in Androt. § 7; in Aristocr. § 99. ) :

For if at any time an act has been committed contrary to law and you have imitated it, it does not therefore follow that you should go scot free; on the contrary it is an additional reason why you should be condemned. For if any of those who transgressed the law had been condemned, you would not have proposed this, and further, if you are condemned, no one else will propose anything of the kind.