In 1584 Reginald Scot published the Discoverie of Witches. Scot was daringly sceptical as to the reality of witchcraft and opposed the persecution of witches, referring to witch hunters as “witchmongers”. This was a courageous position to take in 1584 and copies of his book were burnt when James ascended the English throne at the beginning of the 17th Century, the king himself having authored an anti-witchcraft book in response to Discoverie of Witches. Yet despite the witchcraft trials, as the century progressed Scot’s book was increasingly sought out not for his skeptical viewpoint but as a source for demonic and angelic lore by those who desired to practice magic. “Conjuration and an Excellent Discourse of the Nature and Substance of Devils and Spirits” appeared as appendices to the third edition of Scot’s Discoverie issued in 1665. This can be seen in the context of a number of significant publications with the first issues of English translations of Paracelsus, Agrippa, numerous alchemical works and the popularization of astrology and astrological herbalism. The book is in two parts. The first part details rites of necromancy, the conjuration of infernal spirits, a ritual for the invocation of the magician of his own Genius or Good Angel into a skrying crystal, and a ritual for the obtaining of a familiar. It includes detailed descriptions of ritual regalia and the performance of the rituals. The second part of this volume is a treatise on the nature of spirits.