This Introduction serves to familiarize the reader with theological determinism, explaining what the view is, why so many past and present authors have found it fascinating, and how the chapters of this volume aim to explore it. It begins with a discussion of the view itself, especially focusing on the presence or absence of divine causation and intention within the definition of theological determinism. It then turns to the issue of motivation, noting that the view has found support from religious texts, a belief in causal determinism, and commitment to certain divine attributes, such as providence, knowledge, or aseity. The view has also had its detractors, of course. Historically, most objections have been rooted in one or both of two objections: that the view would eliminate the possibility of human free will and moral responsibility, and that the view would make God the author of sin. Recent work on this topic, including work in this volume, has expanded the scope of arguments, suggesting new reasons to accept the view, and new reasons to reject it. Finally, this Introduction provides an overview of the chapters of this volume.