"Criticism talks a good deal of nonsense, but even its nonsense is a useful force. It keeps the question of art before the world, insists upon its importance, and makes it always in order."

-Henry James

In the Western tradition, literary criticism begins (and in some sense ends) with Aristotle's Poetics, written in the 4th century BCE. That treatise lays out his theories on drama and the principles of literary composition. Aristotle examines the elements of tragedy and defines the three unities of time, place, and action. His ideas on character development, plot, and language continue to influence literary criticism to this day.

In a nutshell, literary criticism is the analysis and evaluation of literature, including poetry, fiction, drama, and nonfiction. It involves examining the literary work's themes, characters, language, and other elements to better understand its meaning, cultural context, and aesthetic qualities.

In the Renaissance, literary criticism took on a new importance, as scholars sought to revive classical ideals of literature and language. Italian humanist and poet Petrarch and English writer Sir Philip Sidney wrote influential treatises on poetry and drama, emphasizing the importance of moral values and aesthetics in literary works.

In the 18th century, the rise of the novel as a popular literary form led to new forms of criticism. The great Samuel Johnson's literary periodicals The Rambler and The Idler both heavily featured criticism, and Johnson's Lives of the Poets remains a classic work of literary biography and critical analysis.

In the 19th century, the Romantic movement challenged traditional literary criticism, emphasizing the emotional power of literature over its formal structure. This led to a new focus on the individual author and the biographical context of their work. Critics such as Matthew Arnold and Walter Pater emphasized the importance of aesthetic values in literature.

In the 20th century, literary criticism became increasingly diverse and interdisciplinary, drawing on fields such as psychology, sociology, and feminism. Notable literary critics of the modern era include T.S. Eliot, Northrop Frye, Harold Bloom, and Roland Barthes.