This article explores the relationship between Heidegger's phenomenological ontology and Maurice Leenhardt's ethnographic study of New Caledonia. For Leenhardt, the kamo, or authentic person, was a participatory personage existing in relationship with other humans, with nature and with mythic beings. He used the term mythe vécu (living myth) to argue for an understanding of myth that was grounded in experience, rather than narrative, and to elaborate his understanding of a uniquely Melanesian mode of Being. I argue that, as well as echoing some of Heidegger's insights, Leenhardt's view of mythic consciousness has much in common with Sartre's analysis of emotional consciousness. The 'experience' I refer to in this discussion is that of the Hula, on the south-east coast of Papua New Guinea. Drawing also on some other Melanesian ethnography, I suggest that an existentialist perspective not only extends the relevance of Leenhardt's interpretation of myth but also constitutes an important development in our understanding of Melanesian ontology.