Literary theory, the systematic study of literature, has broadened in the last century into an interdisciplinary study. It now can involve history, politics, culture, psychology, aesthetics, philosophy, economics and feminism. The list goes on. Most of these are social sciences, but physical science also a part at times. Psychology involves neurology and cognitive functions, economics involves history and trade, and feminism involves social and gender interaction. This is all part of the idea that our social lives inform how we think about the world and subsequently what we write about. So, literary theory is not just about literature anymore. It’s also about us.
The study of literature used to be limited to the “great works” of the literary canon. In the 19th century, more critics and theorists, literary and cultural, noticed how this reflected the general social exclusion of women and minorities. The canon began to expand. Literary criticism still primarily praised “great works” and “literariness,” but the concept of literature also began to diversify socially. Then it would expand and differentiate.
Today, there are literary theorists who study poetry, prose, fiction and non-fiction. But some also study advertising, film, television and political discourse. Some theorists even interpret cultural and historical events as texts. Let’s say you are a literary theorist who specializes in New Historicism, Political Science, Psychology and Anthropology. You could interpret recent events in Egypt just as you could interpret a recent Egyptian novel.
Overall, the point is that literary theory has become broader and intersciplinary. New Historicism, Feminism and Marxism look at the ways history, gender politics and economics shape our social lives and how our social lives shape how and what we write. This is an artistic and scientific endeavor.
At the same time that literary theory was branching out in these ways, you can also trace the development of Formalism (New Criticism) and, to some extent, Structuralism. This was the development of the increasingly scientific study of the textuality of literature. By textuality, I mean what makes literature different from ordinary speech or something like advertising. The Formalists attempted to identify the parts, archetypes, metaphors, tropes, prosody, style, themes, etc. of all literature. They were attempting a very systematic study of what literature is made of. This was very popular at the time and very effective for determining “literature” from other kinds of writing. But it was limiting in its scope and some view it as socially irresponsible. Thankfully, the expansion of literary theory I described above followed quickly and broadened the scientific study to include social sciences with that textual study.
Literature will never be completely scientific. Today, literary theory uses scientific approaches in conjunction with artistic approaches.