John Dee was born in London during the reign of Henry VIII and somehow managed to survive five years into the reign of James I even though he was a scientist and mathematician in a time when everyone knew that “mathematics” was just another word for conjuring. In Tudor/Stuart England, magic was a serious business, if a secretive one. Dee was Elizabeth I’s court astrologer, and alchemists and astrologers like him made incredible discoveries that would inform the future scientific fields of chemistry and astronomy in a time when a change in religious opinion at court could be deadly, and England changed monarchs and state religions with astonishing speed.

Dee denied publicly that he practiced magic, but he secretly believed that “when God created the Universe…he let loose a divine force that causes the planets to turn, the sun to rise, the moon to wax and wane. Magic…is the human ability to tap this force. The better our understanding of the way it drives the universe, the more powerful the magic. In other words, magic is technology.”

Dee’s interest swung freely between what we would see as pure science (such as when a new star appeared in the night sky, and Dee was so obsessed with studying it that he quit the Tudor equivalent of a startup that probably would have paid out a thousand acres of land in Maine, if he hadn’t given up his share) and pure magic (such as his attempts to summon angels).

It’s tempting to see Dee as a misunderstood scientist stumbling through a fog of magic toward the light of pure science. And sure, there are instances when better “magic” would have made Dee a better scientist. When King Edward was dying, for instance, John Dee ran the king’s horoscope before calling for a medical doctor, and the results of the reading informed the decision to essentially put the king into hospice. (Fortunately, Edward had tuberculosis and probably would have died, anyway.) More often than not, magic and science were essential parts of the same process. When he engaged in court-sponsored cryptography research he was also on a quest for the language God used to create the universe, and his interest in code and desire for mystical knowledge fueled each other and inspired him to do better work.