"Known to the West as Averroes, Abu al-Walid Muhammad ibn Ahmad ibn Muhammad ibn Rushd (1126-1198) was the greatest Aristotelian of the Islamic philosophical tradition, composing some thirty-eight book-length commentaries on the "First Teacher's" corpus. The De anima (On the Soul) of Aristotle received particular attention from Averroes, being one of only five works that he treated fully three separate times in works commonly referred to as the Short, Middle, and Long Commentaries." "Written by Averroes at the request of the Caliph Abu Ya qub Yusuf, the Middle Commentary on De anima represents what is arguably Averroes' most sophisticated and politically discreet treatment of a particularly perplexing Aristotelian text. As Alfred Ivry's scholarly notes make clear, there is strong internal evidence to suggest that the Middle Commentary on De anima was actually composed (though not necessarily published) after the Long Commentary. Thus, it may be argued, the Middle Commentary on De anima represents Averroes' final statement on such matters as the material intellect and conjunction - matters upon which he is known to have held different opinions at different times. Dr. Ivry's introduction and notes to the translation situate the Middle Commentary in relation both to Averroes' own other two commentaries on De anima, as well as to Averroes' Greek antecedents, particularly the great Hellenistic commentator Themistius." Averroes' work was important for the transmission and development of the Aristotelian tradition in Europe. His direct influence can be seen in the writings of Thomas Aquinas and in the development of Aristotelianism at the nascent universities of Oxford and Paris. Because he wrote his Middle Commentary on De anima for a lay, if regal, audience, Averroes presents his subject in as uncomplicated a manner as possible, offering modern readers an accessible historical window on Aristotle's work as it was interpreted and transmitted in the medieval period.