 For Avicenna (Ibn Sīnā) metaphysics is a science (ʿilm), i.e., a perfectly rationally established discipline that allows human reason to achieve an authentic understanding of the inner structure of the world. Metaphysics is the science of being qua being and therefore the science that explains every being. In his interpretation, Avicenna fuses the Aristotelian tradition, which he intends to renew (Gutas 2014), with the Neo-Platonic idea of emanation, on which he builds his system: metaphysics thus includes theology, cosmology and angelology, and provides a foundation for physics, psychology, prophetology and eschatology. Indeed, metaphysics even demonstrates “the principles of the particular sciences” that investigate “the states of particular existent things” (Ilāhiyyāt, I, 2, 14, 18–15, 7) and are subordinate to it (Bertolacci 2006: Ch. 7). So metaphysics is “first” and “at the head” of all sciences (Ilāhiyyāt, I, 3, 18, 14–17; Houser 1999; Lizzini 2005) and is universal not only because it concerns being qua being (instead of just some aspects of it), but also because it comprehends reality—and the system of knowledge this implies—as a whole (instead of just some portions of it).