Rudolf Otto’s analysis of religious experience represents one of the most influential developments in modern philosophy of religion, especially through his attempt to explain religion not merely as doctrine, morality, or rational belief, but as a unique type of human experience. His ideas are most fully expressed in his famous work The Idea of the Holy, where he argues that religion is grounded in what he calls the “numinous” experience. Otto’s work can be understood as both a continuation of earlier studies of religious experience and a critique of rationalistic and reductionist interpretations of religion. His ideas are powerful and original, yet they also raise significant philosophical problems. Otto’s central claim is that religious experience is fundamentally non-rational and irreducible. He introduces the concept of the numinous to describe a unique kind of experience characterized by mystery, awe, fascination, and dread. According to Otto, when a person encounters the numinous, they experience what he calls the “mysterium tremendum et fascinans,” meaning a mystery that is both terrifying and attractive. This experience produces feelings of creatureliness, or a sense of dependence before something infinitely greater. Otto insists that this is not simply fear, nor ordinary emotion, but a qualitatively different category of experience. He argues that attempts to reduce religion to ethics, psychology, or social structure fail to capture this essential element. Otto’s work builds upon and reacts to earlier thinkers such as William James, who also emphasized religious experience as central to religion. James studied varieties of personal religious experiences and treated them as psychological realities with practical consequences. However, Otto criticizes purely psychological interpretations, arguing that they fail to acknowledge the objective reality or at least the distinctive quality of the numinous encounter. For Otto, religious experience is not simply a projection of the human mind; rather, it is a response to something wholly other, beyond normal human categories. Otto’s ideas