Mimesis is a rhetorical term for the imitation, reenactment, or re-creation of someone else's words, the manner of speaking, and/or delivery.
As Matthew Potolsky notes in his book Mimesis (Routledge, 2006), "the definition of mimesis is remarkably flexible and changes greatly over time and across cultural contexts" (50). Here are some examples below.
Peacham's Definition of Mimesis
"Mimesis is an imitation of speech whereby the Orator counterfeits not only what one said, but also his utterance, pronunciation, and gesture, imitating everything as it was, which is always well performed, and naturally represented in an apt and skillful actor.
"This form of imitation is commonly abused by flattering jesters and common parasites, who for the pleasure of those whom they flatter, do both deprave and deride other men's sayings and doings. Also this figure may be much blemished, either by excess or defect, which maketh the imitation unlike unto that it ought to be." (Henry Peacham, The Garden of Eloquence, 1593)
Plato's View of Mimesis
"In Plato's Republic (392d),… Socrates criticizes the mimetic forms as tending to corrupt performers whose roles may involve expression of passions or wicked deeds, and he bars such poetry from his ideal state. In Book 10 (595a-608b), he returns to the subject and extends his criticism beyond dramatic imitation to include all poetry and all visual art, on the ground that the arts are only poor, 'third-hand' imitations of true reality existing in the realm of 'ideas.'…
"Aristotle did not accept Plato's theory of the visible world as an imitation of the realm of abstract ideas or forms, and his use of mimesis is closer to the original dramatic meaning." (George A. Kennedy, "Imitation." Encyclopedia of Rhetoric, ed. by Thomas O. Sloane. Oxford University Press, 2001)
Aristotle's View of Mimesis
"Two basic but indispensable requirements for a better appreciation of Aristotle's perspective on mimesis… deserve immediate foregrounding. The first is to grasp the inadequacy of the still prevalent translation of mimesis as 'imitation,' a translation inherited from a period of neoclassicism is which its force had different connotations from those now available… The semantic field of 'imitation' in modern English (and of its equivalents in other languages) has become too narrow and predominately pejorative--typically implying a limited aim of copying, superficial replication, or counterfeiting--to do justice to the sophisticated thinking of Aristotle… The second requirement is to recognize that we are not dealing here with a wholly unified concept, still less with a term that possesses a 'single, literal meaning,' but rather with a rich locus of aesthetic issues relating to the status, significance, and effects of several types of artistic representation." (Stephen Halliwell, The Aesthetics of Mimesis: Ancient Texts and Modern Problems. Princeton University Press, 2002)
Mimesis and Creativity
"Rhetoric in the service of mimesis, rhetoric as imaging power, is far from being imitative in the sense of reflecting a preexistent reality. Mimesis becomes poesis, imitation becomes making, by giving form and pressure to a presumed reality… "
(Geoffrey H. Hartman, "Understanding Criticism," in A Critic's Journey: Literary Reflections, 1958-1998. Yale University Press, 1999)
"The tradition of imitatio anticipates what literary theorists have called intertextuality, the notion that all cultural products are a tissue of narratives and images borrowed from a familiar storehouse. Art absorbs and manipulates these narratives and images rather than creating anything wholly new. From ancient Greece to the beginnings of Romanticism, familiar stories and images circulated throughout Western culture, often anonymously." (Matthew Potolsky, Mimesis. Routledge, 2006)