 Ibn Sīnā (980–1037)—the Avicenna of Latin fame—is arguably the most important representative of falsafa, the Graeco-Arabic philosophical tradition beginning with Plato and Aristotle, extending through the Neoplatonic commentary tradition and continuing among philosophers and scientists in the medieval Arabic world. Avicenna’s fame in many ways is a result of his ability to synthesize and to extend the many intellectual trends of his time. These trends included not only the aforementioned Greek traditions, but also the Islamic theological tradition, Kalām, which was emerging at the same time that the Greek scientific and philosophical texts were being translated into Arabic. Avicenna’s own unique system survives in no fewer than three philosophical encyclopedias—Cure (or The Healing), The Salvation and Pointers and Reminders. Each provides a comprehensive worldview ranging from logic to psychology, from metaphysics to ethics (although admittedly, ethics is treated only scantly). At the middle of this Avicennan worldview is natural philosophy or physics (ʿilm ṭabīʿī). The significance of natural philosophy, and Avicenna’s physics in particular, is twofold. First, it represents Avicenna’s best attempt to explain the sensible world in which we live and to provide the principles for many of the other special sciences. Second, Avicenna’s natural philosophy lays the foundations for a full understanding of his advancements in other fields. Examples of this second point include, but are certainly not limited to, the ramifications of logical distinctions for the sciences, the physical basis of psychology (as well as the limitation of physicalism for a philosophy of mind) and the introduction of key problems that would become the focal points of metaphysical inquiry. In all cases, Avicenna assumes his readers know their physics. 