 Among Avicenna’s summae, the most extensive, influential, and, by the author’s own admission, the most dependent upon Aristotelian sources is the Book of the Cure/Healing (Kitāb al-Šifāʾ). The “traditional” character of the work, however, far from preventing originality, allows the reader to observe more keenly the author’s subtle and wide-ranging adaptation of the Aristotelian model and his free disposal of the received material. This applies to metaphysics in an eminent way. The metaphysical section of the Cure/Healing, The Science of Divine Things (Ilāhiyyāt), comes at the end of a massive work consisting in a collection of twenty-two volumes, which is unique among Avicenna’s summae not only with regard to length (more than 5000 pages in the current printing of the Arabic text, one of the longest works ever written in the history of philosophy) but also because it is the only summa that contains both a full-fledged mathematics before metaphysics, and an extensive treatment of practical philosophy as an appendix to metaphysics. In this way, only in The Science of Divine Things, metaphysics figures as a real cornerstone of the entire philosophical curriculum, both with respect to what precedes (logic and the other two parts of theoretical philosophy), and with respect to what follows (practical philosophy).