Plato sees the artist as an imitator of the physical world around him, which, according to him, is already an imitation of the idea people have of this world. So basically he claims that a writer imitates the imitations and represents imagination and emotion much more than reason and reality. For this reason, according to Plato, mimesis affects the readers negatively by misleading them.
Aristotle disagrees with Plato in the sense that for him to imitate the physical world is not just to copy it but rather to adapt it. According to Aristotle's reception of the mimetic theory, imitation is needed to complete this incomplete physical world people live in. But imitation, as he sees it, is rather a complex creation, a skill that needs to go hand-in-hand with talent and imaginative power. Lodovico Castelvetro and John Dryden support Aristotle's opinion and they view the art of drama as a clear imitation of life.
Horace and Longinus
Horace and Longinus see mimetic theory working only when it is deliberate and an imitation of the ancient works of great artists and writers. Imitation here is the means towards pleasing and entertaining the readers, and this purpose is considered more important than someone trying to be original or copying the world around them. For these philosophers, writers should imitate other people's actions and works instead of physical objects and ideas.
Plotinus agrees with Plato on his theory that art imitates life, but he takes it a step further when he says that this imitation is not without reason or detached from reality. Rather, everything has the ultimate purpose of going back where it came from, and writers imitate the world around them in their struggle to find their way back to their original nature.