Like the Politics, Aristotle's Poetics continues to remain a staple of academic study. At the same time, it also requires context, since the genres of literature have expanded and evolved in so many ways. Aristotle treats the principles of creative writing in general, but his primary focus is on tragedy (it is likely that a parallel treatment of comedy has been lost). While he does consider the epic in some depth, he gives little attention to lyric poetry. Most likely, he believed that this study belonged to the theory of music, though for us the term poetics, as we should expect from the similar cases of physics and psychology, is misleading.

Aristotle establishes early on that with creative writing and perhaps art in general, our concern should be with form rather than purpose. He is not interested in didacticism, but rather poetry as mimesis (a representation). He then goes on to enumerate the characteristics of tragedy, usually referring to Oedipus as his favorite example. Aristotle's approach was decidedly scientific, and to modern readers this might seem incongruous for such a subjective field. He used some form of the scientific method, examining a good number of plays and drawing generalizations from his evidence. His definition of tragedy is perhaps of primary importance: "Tragedy is the representation of an action which is serious, complete in itself, and of a certain limited length; it is expressed in speech beautified in different ways in different parts of the play; it is acted not merely recited; and by exciting pity and fear it produced relief from such emotions." In some senses this definition is very comprehensive, for it explains some of the greatest plays of Aristotle's era. On the other hand, any definition that attempts to be so specific necessarily excludes cases that are traditionally thought to fit the term being defined. Many plays of the period would offer us grounds for protest, not to mention the works of Shakespeare, which often depart from these strict guidelines.

Aristotle continues with his scientific analysis of tragedy, dividing it into the following elements: plot, character, diction, thought, song, and spectacle. Of these six, plot is undoubtedly the most important, as it drives the play–Aristotle believed strongly that character alone was not enough to make a tragedy. He then goes on to separate out the elements of a plot and to demonstrate what constitutes a strong tragedy. Two of the most important are reversals and recognition. A reversal takes place when a key action designed to produce one result actually leads to its opposite. Aristotle's example is when the messenger comes to Oedipus to alleviate his worries, but in the act of revelation actually discloses the information that will lead to Oedipus's downfall. Recognition involves the change from ignorance to understanding, and the ultimate climax of a tragedy comes when recognition and reversal coincide.

As with poetics, Aristotle treats rhetoric as a science, though it is not strictly one. He believes that its study is important for a number of reasons: it can assist in the defense of truth and justice; it can persuade a less intellectual audience that fails to comprehend intellectual demonstration; and it ensures that both sides are considered. Three factors contribute to rhetoric: the personal character of the speaker, the mood that he induces in the audience, and the arguments themselves. His main tools of argumentation are the example and the enthymeme (an argument that could be reduced logically to a syllogism).

Aristotle continues to add divisions, with the application of rhetoric falling into three branches: that of the political assembly, the law courts, and the ceremonial occasion. The remainder of the work consists of further divisions and categories, together with methods of maximizing the effect of one's rhetoric. He also includes a list of nine types of fallacious reasoning, such as generalizing from a single instance, or reversing a premise to reach a false conclusion (e.g., "All young persons are immature. X is a young person. Therefore X is a immature.").

Both Rhetoric and Poetics have had lasting influences. Many still consider his Rhetoric to be helpful as a guideline for speakers, while his Poetics is in many ways a groundwork of literary criticism. While many specific areas have inevitably and long since become dated, many of Aristotle's general principles continue to underlie even modern works.