What do we mean by theory in the arts, and what role does it play there? Theory appears as an active, transformative, fluid and communicative element of art practices and research in the arts in particular. Theory is the fluid that perfuses and connects the territory of fine art and design, as well as all other art forms, including music, architecture, creative writing, moving images, dance and theatre. At the heart of this book is this new field of research of theory and the unique way the ArtEZ Theory in the Arts research group investigates its possibilities and extends its boundaries.