Writing is an eclectic phenomenon whose many facets are studied by the young interdisciplinary field of grapholinguistics. Linguistically, writing is a system of graphic marks that relate to language. Under the lens of processing, it is a method of producing and perceiving utterances with our hands, eyes, and brains. And from a communication theoretical and sociolinguistic perspective, it is an utterly personal medium that allows users not only to convey messages to others but also to associate themselves with cultures or ideologies. These perspectives must merge to become the foundation of a functional theory of grapholinguistics that aims not only to describe how writing systems are built but to explain why they are built that way. Starting with a unified framework that allows the description of all types of writing systems with comparative concepts (such as grapheme) and moving towards the incorporation of evidence from disciplines such as psycholinguistics and sociolinguistics to arrive at explanations, this book establishes the cornerstones of such a functional theory of writing. The Nature of Writing is a collection of ideas about writing, a status report about relevant research, a discovery of desiderata, and a new perspective. It is a start, but most importantly, it is an invitation.