Epiplexis
A reproachful rhetorical question asked not to learn but to shame or rebuke.
Epiplexis is the figure of speech in which the speaker asks a question whose purpose is to reproach the listener rather than to receive information. From Greek epi- ('upon') and plexis ('a striking'), the word carries its function in its etymology: the question strikes at the audience. 'How could you?' is epiplexis in its plainest modern form.
The figure is distinct from ordinary rhetorical questions (erotema), which invite the audience to reach the obvious answer as if it were their own thought. Epiplexis is heavier: the speaker knows the answer and is displeased with it, and the question is the vehicle for the displeasure. It appears constantly in prophetic denunciation, in courtroom cross-examination, and in family arguments.
The craft is in placement. A single line of epiplexis in the middle of an otherwise steady argument lands with force; a paragraph of it becomes a harangue and forfeits the moral advantage the figure requires. The reproach must feel earned by the case just made, not asserted in advance of one.
Common mistake: using epiplexis where the audience has not yet been shown the fault. Reproach without evidence sounds like temper. The order is: establish the failure in plain sentences, then let the question do the striking.
“O generation of vipers, who hath warned you to flee from the wrath to come?”
Keep reading the glossary
The classical name for a rhetorical question — one asked for effect, not for information.
A question asked for effect rather than to elicit an answer.
A rhetorical expression of genuine or feigned doubt about how to proceed — the speaker stops to wonder aloud.
A rhetorical figure in which the speaker asks a question and immediately answers it.