[16], 1221, [49] pp. Engraved architectural title page (4to) 21x17.5 cm (8¼x7"), later marbled paper-covered boards lettered in gilt on morocco spine label. Later edition.

Historians have traditionally regarded the Disquisitionum Magicarum as a receptacle of the ideas of the Malleus Maleficarum ("Hammer of the Witches", 1486). Delrio was credited with importing the beliefs of the Malleus into the Low Countries. Hugh Trevor Roper, for instance, described the book as the "new Catholic Malleus" and claimed that "[i]t was the Catholic reconquest which introduced witch-burning into Flanders, and the Jesuit del Rio who would keep it up", holding the Jesuit directly responsible for the burnings.

Historians have also believed that the work was based on practical experience. Wolfgang Behringer argued that Delrio drew on his experience as a young magistrate, which made him in effect "a colleague of Nicolas Remy". However, it is now recognized that Delrio's personal experience with witchcraft was really rather limited and that he may never have met an alleged witch.