Friedrich Nietzsche claimed to be a psychologist. This claim is substantiated in his criticism of religion. In this book, Jan-Olav Henriksen provides new perspectives on Nietzsche's contribution to such criticism by applying elements from attachment theory and self-psychology. The result is that Nietzsche's insights into the problematic elements in religion point beyond what he was able to articulate based on the psychological resources available to him. Henriksen sheds new light on the psychological dimensions in Nietzsche's individualism, his understanding of God, morality, metaphysics and emotions, and demonstrates how Nietzsche's criticism of religion is rooted in both psychological splitting and a profound loss of the orientational resources religion provided in his childhood.