The western adaptation of non-western medical systems and traditions is a complex process that takes place at a variety of different levels. In many practical medical contexts, epistemological issues receive little attention. Both patients and practitioners may switch frameworks relatively freely, without much concern about underlying theoretical assumptions. Epistemological issues may be more central elsewhere, for example in regard to the licensing and approval of practitioners and medicinal substances, or in terms of the rethinking of western models of knowledge to include new insights from these non-western sources. I suggest in this paper that the major learned medical traditions of Asia, such as Äyurveda and traditional Chinese medicine and traditional Tibetan medicine, for all their differences from biomedicine and among each other, are in some respects relatively compatible with western biomedical understandings. They can be read in physiological terms, as referring to a vocabulary of bodily processes that underlie health and disease. Such approaches, however, marginalise or exclude elements that disrupt this compatibility (e.g. references to divinatory procedures, spirit attack or flows of subtle 'energies'). Other non-western healing practices, such as those in which spirit attack, 'soul loss' or 'shamanic' procedures are more central, are less easily assimilated to biomedical models, and may simply be dismissed as incompatible with modern scientific understandings. Rather than assenting to physiological reduction in the one case, and dismissal as pre-scientific in the other, we should look for a wider context of understanding within which both kinds of approach can be seen as part of a coherent view of human beings and human existence.