Book excerpt: Understanding the Psychological Soul of Spirituality is a comprehensive exploration of spiritual constructs based on an empirical, evidence-based paradigm for understanding and addressing spirituality. In a field where there is no current consensus on spirituality, this book provides a much-needed psychologically based definition and ontology that assists helping professionals in formulating their professional identities; developing effective and appropriate training models; furthering their understanding of what spirituality is and is not, from a psychological perspective; and more effectively addressing spiritual issues to support clients. The authors provide a review of current issues in the area of spirituality, also called the numinous, and provide perspectives that address these concerns in ways that promote a fully scientific understanding of the construct. Ultimately the book provides a concise definition of the numinous that places it squarely in the social sciences. Chapters outline the clear value of the numinous for psychology and detail its relevance for professionals’ training.