Accumulatio

Accumulatio (Latin 'a heaping up') is the figure of summary intensification. Having made a series of points in the course of an argument, the speaker gathers them at the end into a compressed list, often in a single sentence, so that the audience feels their combined weight. It is a device of perorations: the moment before the conclusion, when the speaker wants the accumulated evidence to be present all at once.

The figure differs from mere summary. A summary re-states the points at their original length; accumulatio compresses them, often to a word or a phrase apiece, and lets the rhythm of the enumeration do work that a full re-statement could not. Cicero's speeches close on accumulatio again and again, and the closing paragraphs of Lincoln's Second Inaugural read as an accumulatio of the whole speech's themes.

It is closely allied to congeries (a pile-up of near-synonymous terms) and to enumeratio (a laid-out list of parts). The distinguishing note of accumulatio is that its list is retrospective: every item in it has already been argued for. The audience does not have to accept the items on the speaker's word, because the speaker has already made the case for each one.

Common mistake: producing an accumulatio for material the speaker has not in fact established. The figure has real emotional force, and a rhetor can be tempted to use that force to smuggle claims that were never argued. Audiences trained to hear accumulatio hear the smuggle; the figure loses its power when it is used dishonestly.