Although revered in his own time, John Dee (1527-1608) was until recently regarded as an isolated crank on the margins of Tudor history. This anthology of Dee's writings illustrates his diverse interests and his central position in the history of Renaissance thought and the development of Western Magic. Dee's celebrated Preface to Euclid is included along with selections from his Spiritual Diaries and letters to other mystics and royals. In addition to Hermetic and Cabalistic philosophy, mathematics, astronomy, astrology, and navigation are also covered.