Various theories have been put forward to account for the existence of witch beliefs. Among those advanced to account for their occurrence in early modern Europe is that of Margaret Murray, a British Egyptologist, who considered the witches of western Europe to be the lingering adherents of a once general pagan religion displaced by Christianity. Most contemporary scholars in witchcraft reject this theory as unfounded historically. A more recent theory relating to the so-called European witch mania lasting from the mid-15th to the mid-18th century is that of the British historian Hugh R. Trevor-Roper. He views witchcraft as an outgrowth of the systematic "demonology" that the medieval church constructed out of the scattered folklore of peasant superstitions and that acquired a momentum of its own in the centuries of political and religious strife that transformed Europe from the so-called Dark Ages to the modern period.

Theories of more general applicability include the diffusionist, psychological, and sociological theories of various anthropologists and historians. Diffusionist theories are concerned with accounting for the distribution, either at present or in historical times, of beliefs and practices relating to witchcraft; e.g., viewing Pueblo witch beliefs as an amalgam of Spanish and Indian influences. Psychological theories stem ultimately from Freud's doctrine of the displacement of affect (that emotions repressed in one situation find an outlet in another), as exemplified in the theory of Malinowski, who regarded magic (including sorcery) as institutionalized "substitute activity" resorted to when urges for survival or for revenge are blocked by the inadequacies of technology or (following Clyde K.M. Kluckhohn's development of the theory) are limited by the closeness of social relationships that can be ended only with great difficulty.

Sociological theories of witchcraft stem from Evans-Pritchard's work among the Azande and illuminate two fields, the sociology of knowledge (the social conditions of knowledge and explanation) and the study of the micropolitical processes, already noted above. Although Evans-Pritchard's book was a study in the sociology of knowledge in a particular society, it contained several acute insights into the links between social structure and belief that led other investigators to consider applying them in their studies of other societies. As a result there has emerged a body of theory that takes the relative frequency of accusations or supposed instances of witchcraft or sorcery to be social strain gauges that reveal which roles and relationships in a social system are especially subject to tensions--tensions for which articulation and periodic discharge must be provided if the structure is to survive.