Plato said that lexis can be divided into mimesis (imitation properly speaking) and diegesis (simple narrative).
Diegesis and mimesis combined represent the fullest extent of lexis; both forms of speech, narrating and re-enacting.
Within lexis the two areas of differentiation of mimesis (imitation) are diegesis (narrative) and the "direct representation of the actors speaking to the public.
"[3] According to Jose M. Gonzalez, "Aristotle instructs us to view of his psychology, as mediating the rhetorical task and entrusted with turning the orator's subject matter into such opinion of the listeners and gain their pistis.
Gonzalez also points out that, "By invoking phantasia, lexis against the background Aristotle instructs us to view of his psychology, as mediating the rhetorical task and entrusted with turning the orator's subject matter into such opinion of the listeners and gain their pistis."
Although Aristotle at times seems to demean the art of diction or 'voice,' saying that it is not an "elevated subject of inquiry," he does go into quite a bit of detail on its importance and its proper use in rhetorical speech.
The manner of voice in which an idea or speech is conveyed affects not only the emotions of the audience but, also, their ability to understand this concept.
According to Taylor Stoehr, "voice is the pervasive reflection in written or spoken language, of an author's character, the marks by which we recognize his utterance as his.".
[10] However, just as in Aristotle's time set of specific rules or guidelines has yet been laid out for the production or interpretation of voice.
According to Aristotle, lexis, meaning the delivery of words, is the least important area of speech when in comparison to invention, arrangement and style.
Although for Aristotle, lexis graphike is the most accurate delivery of language, which leads to his theory that proves that writing does not need to be questioned because it is already exact.
The delivery of lexis graphike is designed for a careful reading from either the book or paper as opposed to a performance that leaves room for improvisation.