Aristotle Rhetoric 3.1.3

[3] In the first place, following the natural order, we investigated that which first presented itself—what gives things themselves their persuasiveness; 20 in the second place, their arrangement by style; and in the third place, delivery, which is of the greatest importance but has not yet been treated of by anyone. In fact, it only made its appearance late in tragedy and rhapsody, for at first the poets themselves acted their tragedies. ¹ It is clear, therefore, that there is something of the sort in rhetoric as well as in poetry, and it has been dealt with by Glaucon of Teos among others.