Academics tend to look on 'esoteric', 'occult' or 'magical' beliefs with contempt, but are usually ignorant about the religious and philosophical traditions to which these terms refer, or their relevance to intellectual history. Wouter Hanegraaff tells the neglected story of how intellectuals since the Renaissance have tried to come to terms with a cluster of 'pagan' ideas from late antiquity that challenged the foundations of biblical religion and Greek rationality. Expelled from the academy on the basis of Protestant and Enlightenment polemics, these traditions have come to be perceived as...