Taking a unique approach which combines sociolinguistics with theoretical linguistics, this book presents a view of language and grammar as simultaneously a cognitive and socio-cultural phenomena. Showing how language development can act back on central areas of grammar and language, this book explores the notion that different branches of linguistics can complement each other and are not mutually exclusive. Beginning with Bakhtin's concepts of conceptual grammar and lexico-grammar, this book encompasses a broad philosophical range, dealing with key figures such as Bergson, Chomsky, Derrida and Wittgenstein. Drawing on the ideas of these philosophers, David Evans explores how language progresses from an inner reflection of the rational mind to develop social and ideological aspects as it interacts with culture. In such a progression, this book shows how identity is unitary and rational at the linguistic core whilst at the same time multiple social identities are shaped by linguistic differences at the cultural peripheries. Encompassing theoretical linguistics, cognitive linguistics, discourse analysis, multilingualism, sociolinguistics and semiotics, Rationality and Interpretation demonstrates how language development has socio-cultural influences, while at the same time these influences impact language development.