This collection brings together new papers addressing the philosophical challenges that the concept of a Devil presents, bringing philosophical rigor to treatments of the Devil. Contributors approach the idea of the Devil from a variety of philosophical traditions, methodologies, and styles, providing a comprehensive philosophical overview that contemplates the existence, nature, and purpose of the Devil. While some papers take a classical approach to the Devil, drawing on biblical exegesis, other contributors approach the topic of the Devil from epistemological, metaphysical, phenomenological, and ethical perspectives. This volume will be relevant to researchers and scholars interested in philosophical conceptions of the Devil and related areas, such as philosophers of religion, theologians, and scholars working in philosophical theology and demonology.