F.R. Leavis and his wife, Q.D. Leavis advocated for what they called the "great tradition" in literature, which meant that "literature" could be understood as the works of those authors who best upheld the tenets of liberal humanism: that is, that literature should be timeless, that its meaning should be accessible without referring to any context other than the work itself, and that a work is best understood by examining the text alone. Leavis believed that the purpose of literature was the promote human values, which meant for him things such as "human nature" and psychological individualism. Q.D. Leavis explicitly saw popular fiction as a corrosive influence on literary culture, and underlying the work of both Leavises is a conservative, moralistic, and elitist view of literature and criticism.
C.S. Lewis opposed Leavis's formulation of literature as an expression of liberal humanism; for Lewis, this meant that literature was always a kind of dead end, in the sense that by definition, "literature" in the Leavis formulation could always only reflect liberal humanist values. Lewis put more value on the use of imagination in literature and in effect inverted the Leavis model of criticism by shifting focus from the work to the reader and examining what makes a "good reader."
The literary criticism by the Leavises in such books as Fiction and the Reading Public (1932) and The Great Tradition (1948) is based on the assumption that there is only one form of great literature, that practised by a restricted literary elite. Leavisite criticism is therefore hostile to popular culture which does not merit the title of literature. Both critics denounced the corrupting effect of popular literature and the expansion of the reading public. This notion of a single culture has been challenged since the introduction of Cultural Studies on the literary scene in the 1960s.
As the author of many children's books such as the seven-volume series The Chronicle of Narnia (1950-56), C. S. Lewis wrote popular literature. To him, popular fiction was a way to communicate Christian teachings to a large audience and, thus, it had an important function. His literary criticism too focused mainly on texts with a religious message, particularly from the Middle Ages. Emotions are therefore considerably more important for Lewis than for the Leavises who argued for a literary criticism that could put together scientific and humanistic thoughts.