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.