AbstractThe literature has tended to deal with diviners only where they have been seen to play a notable role in the transformation of social relationships. This leads us to overlook their relative social invisibility in many African societies. Yet we may gain insight into the rise of prophets and charismatic healers by looking at the other side of this story in the multitude of very humble practitioners plying their trade. This is the context in which this article explores the role of diviners among the Gisu of Uganda.The privacy of consultation, the search for distant diviners, the way they are approached only at times of crisis and as agents of private counteraction or vengeance, go some way towards explaining why it is difficult for diviners to gain recognition. Added to which are the difficulties of another order which relate to what might here be regarded as divinatory success. For divination may be seen to fail at a number of different levels: in the lack of credibility of a given practitioner, i n a lack of unanimity among those consulted and in the multiplicity of causal agents evoked.An argument put forward here is that scepticism is endemic to the system and, possibly, distinctive to it. We should ask not, as Evans-Pritchard did, how belief i s sustained despite the presence of scepticism but what it is about these beliefs which encourages scepticism. It is not useful to explore this issue in terms of the rationality question or the ‘truth’ of belief systems. If we are to draw a comparison with modern attitudes, of greater significance are the organisation and differentiation of knowledge and its relationship to power. It is suggested that diagnostic systems used by societies such as the Gisu encourage an agnostic attitude in a way i n which those of the modern West do not.In the final part of the article the social role of divination is reconsidered and some of the positive functions proposed for it are questioned. Gisu divination can be seen to have evolved into a very narrow niche whose parameters are bound, on the one hand, by the limits of belief and, on the other, by a system of interpersonal vengeance. We may say that the socially marginal attributes of diviners, exclusively concerned with the negative aspects of social relationships, represent a real social marginality. At best they are agents by which the individual may be reconciled with harshnesses imposed by his own destiny, of ancestral affliction; at worst they are agents of individual vengeance and retribution. This may be taken as more or less disqualifying them from articulating a positive, future-oriented vision on behalf of the community. Clearly it is not impossible but it is a huge jump from these humble practitioners, interpreting the present in terms of the past and trading evil with evil at an individual level, to prophets capable of formulating a positive social vision, a means forward, on behalf of a wider moral or social community.