Horace's phrase 'ut pictura poesis' translates to 'as is painting, so is poetry.' It suggests that poetry should possess the vivid, descriptive qualities of a painting, effectively creating a visual experience for the reader through language. This doctrine influenced centuries of literary criticism regarding the relationship between the visual arts and literature.

Like the foundational work of Plato and Aristotle, who sought to define the nature of truth, ethics, and art, literary theory functions by interrogating the underlying assumptions of literature. It moves beyond simple reading to ask ontological and epistemological questions about how meaning is produced, while simultaneously constructing rigorous, systematic frameworks—such as structuralism or Marxism—that provide scholars with specific methodologies for interpreting and evaluating literary texts within a broader intellectual context.

Peripeteia, or 'reversal of fortune', is a pivotal element in Aristotelian tragedy. It describes the sudden shift in the protagonist's circumstances, typically moving from a state of prosperity or high status to one of misery or downfall. This reversal is often linked to the hero's hamartia (tragic flaw) and is essential for evoking the tragic emotions of pity and fear in the audience.

Derived from Aristotle's Poetics, catharsis describes the emotional purging or cleansing experienced by the audience during a tragedy. It is achieved through the arousal of pity and fear, allowing the spectator to experience a release of these intense emotions by the play's conclusion.

Aristotle identifies ethos as one of the three modes of persuasion, alongside logos and pathos. Ethos refers to the credibility and moral character of the speaker. To be persuasive, the speaker must project an image of wisdom, virtue, and goodwill. By convincing the audience that they are a person of integrity and sound judgment, the speaker gains the audience's trust, which is essential for the effectiveness of their argument.

Logos is one of the three modes of persuasion identified by Aristotle. It functions by appealing to the audience's sense of reason. By utilizing empirical evidence, statistics, historical facts, and logical syllogisms, a writer constructs a rational argument that is intended to be intellectually convincing rather than merely emotionally or ethically persuasive.

Aristotle's 'Poetics' is the definitive text where he outlines the essential elements of tragedy, including the six parts of a play: plot, character, thought, diction, melody, and spectacle. He famously defines the tragic hero's downfall as resulting from 'hamartia' (a fatal flaw) and discusses the emotional effect of tragedy on the audience, known as catharsis.

The term 'katharsis' (or catharsis) is famously central to Aristotle's definition of tragedy in the 'Poetics', yet it appears explicitly only twice in the extant text. Its scarcity has led to centuries of scholarly debate regarding its precise meaning—whether it refers to a medical purgation of emotions or a moral clarification—making it one of the most discussed concepts in classical literary theory.

While Horace wrote the poem as a letter to the Piso family, it was the Roman rhetorician Quintilian who later referred to it as 'Ars Poetica' (The Art of Poetry). This title became the standard designation for the work, which provides essential guidance on the craft of writing, dramatic structure, and the role of the poet.

Aristotle argues in his Poetics that the resolution of a tragedy must be a logical consequence of the preceding events. He explicitly criticizes the use of 'deus ex machina' or external supernatural intervention, insisting that the plot should be internally consistent and resolved through the actions and character choices established within the narrative.