 His original works, many listed in the "Fihrist" of Ibn al-Nadim, dealt with contemporary science, medicine, astronomy and philosophy.A Latin translation of his work ‘On the Difference between the Spirit and the Soul’ (De Differentia Spiritus et Animae) was one of the few works not attributed to Aristotle that was included in a list of ‘books to be 'read,' or lectured on, by the Masters of the Faculty of Arts, at Paris in 1254, as part of their study of Natural Philosophy.This translation was made by Joannes Hispalensis, (John of Seville, fl.