Fusing medicine and astrology together, the astrological physician is one of the strangest works of the 17th century. A precursor to later, more lasting attempts at mixing the spiritual and the scientific, a rudimentary observation of stars and planets is all that is needed, according to this work, to diagnose and treat illness. Using the theory of the humors, it also proclaims the ability to determine whether a malady is caused by demons or witches.