In the first two essays of this reference guide, Donald Holland introduces the historical definitions of deviance and Karen M. Harbeck examines the biological and psychological theories of nonconformity. Holland’s historical overview also introduces the deviance theories of Émile Durkheim and Howard Becker. Cynthia Vejar further develops the discussion by examining Durkheim’s theory that criminality, among other deviant behaviors, is both a normal and functional element in the creation of a normative social body. Several essays in this volume approach the subject of criminality following a methodology that owes to Durkheim’s social perspective, where criminality is perceived as being tied to the subject.