 His treatise "Introductorium in Astronomiam" ("Kitab al-Mudkhal al-Kabīr") spoke of how '"only by observing the great diversity of planetary motions can we comprehend the unnumbered varieties of change in this world".The "Introductorium" was one of the first books to find its way in translation through Spain and into Europe in the Middle Ages, and was highly influential in the revival of astrology and astronomy there.Persians also combined the disciplines of medicine and astrology by linking the curative properties of herbs with specific zodiac signs and planets.