Lives of Eminent Philosophers 7.42 — Diogenes Laërtius on the Stoics

Diogenes Laërtius, Lives of Eminent Philosophers 7.42

Reported speech · Diogenes Laërtius on the Stoics

Now the part which deals with canons or criteria they admit as a means for the discovery of truth, since in the course of it they explain the different kinds of perceptions that we have. And similarly the part about definitions is accepted as a means of recognizing truth, inasmuch as things are apprehended by means of general notions. Further, by rhetoric they understand the science of speaking well on matters set forth by plain narrative, and by dialectic that of correctly discussing subjects by question and answer; hence their alternative definition of it as the science of statements true, false, and neither true nor false. Rhetoric itself, they say, has three divisions: deliberative, forensic, and panegyric. Rhetoric according to them may be divided into invention of arguments, their expression in words, their arrangement, and delivery; and a rhetorical speech into introduction, narrative, replies to opponents, and peroration.