This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book presents the general conception of realism and anti-realism, both local and global. It provides two sorts of anti-realism: object anti-realism, which concerns putative entities of some specific type, and a more general category. The book explores the relationship between various anti-realist accounts of reference and global object anti-realism. Michael Dummett is largely responsible for the trend away from speaking of realism tout court, and toward speaking of realism or anti-realism with respect to this or that specific subject matter. Dummett contends that disputes ranging over a wide variety of subject matters, from the external world to mathematics, exhibit this common structure. The book examines the question of whether anti-realism about linguistic meaning and mental content gives rise to global statemental antirealism.