Some anthropologists prefer clear-cut depictions of the societies they study, preferring to ignore differences of opinion, failures of belief, and expressions of scepticism and doubt. This tendency is increasingly being challenged, and an emerging literature now explores scepticism. Contributing to this literature, I discuss the scepticism towards witchcraft expressed by my interlocutors in the Papua New Guinea highlands province of Chimbu. I do not juxtapose witchcraft to science, for witchcraft must be taken seriously â€“ especially since accusations often have severe consequences. Expressions of scepticism bring into doubt the absolute certainty of witchcraft as the explanation for misfortunes such as illness and death, and its study provides a more nuanced picture of a society, showing how cultural norms can be transformed and the foundations of violence can be disrupted. This applies to the scepticism I heard expressed, because the challenge it poses to witchcraft accusations may help prevent further violence. An anthropology of scepticism could usefully be applied more broadly to many aspects of culture, since study of scepticism is one way of reaching an understanding of how social change occurs.