The thesis introduction identifies the many theoretical approaches to myth, and reveals the need to find a new approach to the study of myth in the works and thought of C. S. Lewis. Most approaches to the study of myth are criticised by Lewis and his literary group of friends, known as the Inklings, as reductive. In contrast, Lewis proposed a more holistic, transcendent power of myth. The first chapter explores the specific importance of myth to Lewis' developing thought, from his early experiences of Norse myth to the development of his views in debate and through his involvement with the Inklings. Tensions and inconsistencies in Lewis' statements about myth are explored and the chapter culminates with Lewis' appreciation of myth in Christian faith, literature, and his realisation of myth as an object of contemplation. Chapter Two explores and contrasts the theories and approaches to myth of Ernst Cassirer with those of Lewis. Both thinkers are compared and areas of similarity and difference are identified, including their reactions to the problem of myth and Nazi ideology. Chapter Three applies the phenomenological traits, characteristics and principles of myth developed by Cassirer to Lewis' science fiction fantasy Perelandra. Mythical consciousness is evoked in this work through mythical images, the inner form of myth, and the type of worldview that threatens to engulf Ransom. We can observe the way that myth involves a sense of unification. Chapter Four identifies the symbolic form of myth in Till We Have Faces. The general characteristics of myth are explored and the inner form, or particular logic, of myth is revealed to actively form the mythical relations that dominate the lives of the characters. The function of myth as a form of thought is explored in the novel. Chapter Five delineates the symbolic form of myth within The Lion, the Witch, and the Wardrobe, with particular emphasis upon Lewis' handling of demonic and divine forces and the mythical concept of sacrifice and rebirth. In conclusion, a more holistic appreciation of myth in Lewis' works and thought is developed through the application of Cassirer's myth principles to Lewis' works. Apparently disparate aspects of myth are revealed to have a cohesive unity in mythical consciousness.