Book of the Luminaries

The Book of the Luminaries (Sefer ha-me’orot) is a work of medical astrology dealing with the effects that the sun and moon (the “luminaries”) have on the course of a disease. Ibn Ezra composed two versions of Sefer ha-me’orot, the first in Béziers, southern France, in 1148 and the second sometime thereafter, perhaps in northern France or in London. Like many of his other writings, it was translated into Latin. These excerpts describe the sun and the moon, their motion and other characteristics, and the obvious effects they have on the sublunar world, on which, Ibn Ezra points out, astrologers have based their discipline. Unusually for Ibn Ezra’s more technical astrological works, the descriptions weave in biblical language, primarily from the creation story in Genesis. The last excerpt shows Ibn Ezra responding to a typical objection to medical astrology.