Comparative Literature emerged as a term in the mid-19th century, originally used to describe comparative analyses of different national literatures. It was first used by Matthew Arnold in 1848 to refer to the comparative survey of poetry between different nations. The term became more popularized in France and was used to establish the field as one focused on the "binary relations" between two or more literatures, distinguished from the more general study of literature. Some key debates around Comparative Literature include its purpose and whether it should include the study of folklore and other non-literary works. Seminal works that helped establish it as a discipline include Wellek and Warren's "Theory of Literature" and works by Harry Levin,