It is no exaggeration to say that all Western literary criticism flows from Aristotle. In the Poetics he focuses mainly on drama, especially tragedy, and introduces ideas that are still being debated more than two thousand years later. Among them is the often misunderstood theory of the unities of action, place, and time, as well as such concepts as: art as a form of imitation, and drama as an imitation of human actions; plot as a drama’s central element, and "reversal” and "recognition” as important elements within a plot; and the purging of pity and fear from the audience as the function of tragedy. Rather than offer these ideas merely as abstract theories, Aristotle applies them in cogent analyses of the classic Greek dramas—the tragedies of Aeschylus, Sophocles, and Euripides.
In the Rhetoric, Aristotle turns to the principles of persuasive writing, including argumentation and the logical development of proof, appeals to emotion, and matters of delivery and style. Perhaps most essentially, Aristotle teaches us how to engage in the central civic activities of accusing and defending, recommending policies, and proving and refuting ideas.
These two foundational works are key documents for understanding the culture and politics of Western civilization, and how they continue to evolve today.