This introductory chapter outlines the purpose and motivation of the book, offering an overview of the historical evolution of the concept of gratitude and addressing key contemporary debates in its philosophical and psychological investigation. It also briefly introduces the concept of transpersonal gratitude. The chapter provides an overview of the book’s structure, organised around four key areas of inquiry: the currently dominant philosophical perspective on gratitude and some of the challenges presented by the concept of dyadic gratitude; the conceptualisation of transpersonal gratitude as a concept that accounts for a genuine dyadic modality of gratitude; the main phenomenological features of transpersonal gratitude; and the ethical implications and moral import of transpersonal gratitude.