Institutio Oratoria

Consequently we must regard partition not as one part of a whole speech, but as a part of each individual question that may be involved. For what question is there in which an orator cannot set forth the order in which he is going to make his points? And this of course is the function of partition. But how ridiculous it is to make each question an aspect of proof, but partition which is an aspect of a question a part of the whole speech.

As for digression (egressio, now more usually styled excessus ), if it lie outside the case, it cannot be part of it, while, if it lie within it, it is merely an accessory or ornament of that portion of the case from which digression is made. For if anything that lies within the case is to be called part of it, why not

On the other hand I disagree with those who, like Aristotle, [*](Rhet. ii. 26. ) would remove refuation from the list on the ground that it forms part of the proof: for the proof is constructive, and the reputation destructive. Aristotle [*](Rhet. iii. 13. ) also introduces another slight novelty in making proposition, not statement of facts, follow the exordium. This however he does because he regards proposition as the genus and statement of facts as the species, with the result that he holds that, whereas the former is always and everywhere necessary, the latter may sometimes be dispensed with.