The occult was a crucial influence on the Renaissance, and it obsessed the popular thinkers of the day. But with the Age of Reason, occultism was sidelined; only charlatans found any use for it. Occult ideas did not disappear, however, but rather went underground. It developed into a fruitful source of inspiration for many important artists. Works of brilliance, sometimes even of genius, were produced under its influence. In A Dark Muse, Lachman discusses...