This introduction presents an overview of the key concepts covered in the subsequent chapters of this book. The book deals with modes of existence of literature and, thus, its main topic might be called ontology of literary works. Each of these modes of existence involves a corresponding method of research. The research associated with the first mode includes neuro-scientific and cognitive approaches to art and literature along with its empirical studies, whose overall concern is to explore how the mental processes associated with everyday cognition are applied to creation and experience of literature. In the typology proposed here, one broad new orientation in literary studies is the tendency toward drawing from the sciences and naturalizing the humanities, which is largely shaped by various modern approaches to the study of the mind and to cognitive science. Aesthetics is either a philosophical exploration of structured pleasurable sensual experiences or a philosophy of art.