Ekphrasis, a species of vivid description, has no formal rules and no stable technical definition. Originally a device in oratory, its development as a poetic figure has somewhat confused its taxonomy, but broadly speaking it is one of a spectrum of figures and other devices falling under the rubric of enargeia (‘vividness’). The term ekphrasis appears only belatedly in classical rhetorical theory. Discussing representation in his Rhetoric, Aristotle approves the ‘enlivening of inanimate things’ with vivid description, the ‘do[ing of] something to the life’ as a kind of imitation, in metaphors which ‘set things before the eye’. Quintilian regards vividness as a pragmatic virtue of forensic oratory: ‘“representation” is more than mere perspicuity, since instead of being merely transparent it somehow shows itself off … in a way that it seems to be actually seen. A speech does not adequately fulfil its purpose … if it goes no further than the ears … without … being … displayed to the mind's eye.’ The rhetor Dionysius of Halicarnassus (fl. 30–7 Bc) makes the first surviving use of the term ekphrasis, but it was during the Second Sophistic (1st–4th c. AD), when earlier Greek rhetoric became the model for Latin practice, that the term was given firm definition and purpose.