Heinrich Cornelius Agrippa (1486-1535) was a German polymath, physician, legal scholar, soldier, theologian, and occult writer. He is considered one of the most influential occultists of the early modern period. Eric Purdue is a practitioner of medieval astrology and an active santero/olorisha. He has studied metaphysics and magic for over 30 years, with a particular focus on practical planetary and folk magic. He lives in Seattle, Washington.