 This tendency has had repercussions for the study of magic, with academics self censoring their research because of the effects on their careers.Randall Styers noted that attempting to define magic represents "an act of demarcation" by which it is juxtaposed against "other social practices and modes of knowledge" such as "religion" and "science".The historian Karen Louise Jolly described magic as "a category of exclusion, used to define an unacceptable way of thinking as either the opposite of religion or of science".