Colloquially known as "the little voice in the head" inner speech is an important and fascinating topic at the intersection of several areas of philosophy, as well as related disciplines, such as psychology, linguistics and cognitive science. Yet until now it has received remarkably little philosophical attention. What exactly is inner speech? Is it a form of language or a form of thought in its own right? Is it distinctive of human cognition, or also shared by non-human animals? In this thorough and clearly-written introduction to inner speech, by a leading authority on the subject, Peter Langland-Hassan examines and assesses the following: inner speech in recent historical context, including the theories of Vygotsky and Noam Chomsky the nature of inner speech, especially the relation between language and mental content and the use of computational frameworks for understanding inner speech the role and function of inner speech, including its integrative role, collecting information from a variety of cognitive modules, and its relation to memory inner speech and consciousness and self-awareness "hearing voices" and inner speech in relation to the disordered mind, including schizophrenia. Additional features, such as chapter summaries, annotated further reading and a glossary make this an excellent resource for students of philosophy of mind and psychology, psychology, and cognitive science.