This e-book is concerned with metatheories in Library and Information Science (LIS) and especially with the philosophy of science of LIS. Metatheories are theories about the description, investigation, analysis or criticism of the theories in a domain. They are mostly internal to a domain, and may also be termed “paradigms”, “traditions” or “schools”. This issue is termed “Library and Information Science and the Philosophy of Science” to indicate that the emphasis is on basic approaches developed and generally well known outside of LIS (such as critical realism, empiricism, hermeneutics and pragmatism). Here these general views are interpreted and investigated within the context of LIS. Such approaches deal with how knowledge is understood and acquired and are important in discourses of the foundations of any domain.