Literary theory systematically studies the nature of literature and its analysis methods, evolving since the 19th century into an interdisciplinary field influenced by philosophy, semiotics, and cultural studies. While formally established as a profession in the 20th century, its roots span back to ancient Greece with Aristotle's Poetics, ancient India, and Rome, continuing through medieval scholars. Central to this field are fundamental questions like "what is literature?" and "how should we read?", with many theorists acknowledging that texts often hold multiple, non-fixed meanings.
Numerous schools of thought, including New Criticism, Marxism, feminism, and post-structuralism, employ distinct interpretive methods. These approaches often reflect diverse moral and political commitments, leading to significant academic debates, famously dubbed the "theory wars" in the 1980s and 90s, concerning what it means to theorize about literature.