The real subject of Paul Tillich’s three-volume Systematic Theology is not God but rather the history of Tillich’s personal relationship with God.The religious experiences to which Tillich refers in this,his major work,are his own,although he never admits it.This article attempts to draw parallels between Tillich’s mystical development and that of other mystics.Questions are raised about the possibility of mystical voices,visions,ecstasies,raptures and deliria being symptoms of schizophrenia.