Descriptively, theory of literature is therefore modern: it assumes the existence of literary studies, inaugurated in the nineteenth century and emerging from Romanticism.
It is not unrelated to the philosophy of literature as a branch of aesthetics, which reflects on the nature and function of art, on the definition of beauty and value.
Theory of literature, as in Wellek and Warren's manual, which bears this phrase as its title--Theory of Literature (1949)--is generally understood as a branch of general and comparative literature: it designates reflection on the conditions of literature, of literary criticism and literary history; it is the criticism of criticism, or metacriticism.
In contrast to the literature of the earliest ages, which is characterized by collective artistic activity, that of later ages shows the effects of political, economic, and cultural changes as the peninsula increased in wealth and widened its contacts with other areas.
In contrast to that of Koguryo, the literature of Paekche and Silla tended to be lyrical, perhaps because of the milder climate and easier life in the south.
As a literature of the privileged class, the popularity of the akchang was always limited, and it was soon eclipsed by the most important forms of the Yi dynasty--sijo and kasa.