Book excerpt: This is the first English translation of one of the most important, interesting and comprehensive discussions of the occult sciences ever published. Investigations into magic deals not only with magic in all its forms, from the manipulation of angelic and demonic powers to straightforward conjuring and illusion, but also with witchcraft, alchemy, astrology, divination, prophecy, and possession by evil spirits. In addition, Del Rio gives judges and confessors practical advice on the most effective ways of dealing with people who are accused of practising magic, and enlivens his whole discussion with anecdotes drawn from a remarkable range of sources, including his own experience. Nothing so panoramic had ever appeared before, and for the next one hundred and fifty years Investigations into magic was the indispensable reference work on the subject.