Living Sora hold frequent dialogues with the dead, who speak with them through mediums in trances. The thesis explores the problems of understanding which this presents to the anthropologist. It takes the awareness of mortality as a universal human experience which is however discussed differently in different cultures, according to their underlying metaphysical assumptions. Sora trance is considered as a technique for operating on this experience by means of a postulate (sonum, conventionally translated as 'spirit') which represents the continuing influence of a dead person on the living. The thesis is built on the analysis of extensive tape- recorded dialogues between mourners and the dead. It falls into three parts. Part I outlines the relevant areas of Sora ethnography and metaphysics. After sketching in something of Sora politics and social structure, it discusses their view of the person, of relations between persons and of "subjective" and "objective" reality. This leads to the crucial Sora dichotomy between the Ancestor and Experience aspects of the dead suid the mapping of these on to incompatible areas of the landscape. Part II examines a funeral dialogue in which the deceased is cross-examined to establish the nature of his Ancestor and Experience aspects. The subsequent attempts to transform the terms of this verdict in order to modify his future influence on the survivors leads to a discussion of the grammar of verbs of experience and suffering and thence to a provisional English translation of the word sonum. Part III develops the implications of this translation across time. A series of linked case-studies explores the healing of private emotion, the arguing out of ambiguities in inheritance and in the unfolding of the lineage, and finally the Sora sense of the interplay between transience, permanence and repetition and with this the counterbalancing of grief with joy. A final chapter discusses the inadequency of any translation of sonum by making a comparison with Freud's theory of bereavement.