The Book of Definitions and Descriptions

The Book of Definitions and Descriptions (Kitāb al-ḥudūd wa-’l-rusūm) is a collection of fifty-six definitions of philosophical terms, mostly drawn from the Abbasid philosopher al-Kindī (d. ca. 870), clarifying disagreements among “the ancients” regarding philosophical terminology. As elsewhere, al-Isrā’īlī’s views are thoroughly Neoplatonic, though some of his views in this work cannot be reconciled with his other writings. This work, written in Arabic, was translated at least twice into Latin, where it found a warm reception among Christian scholastics, and twice into Hebrew. The excerpts here are definitions: of humans, of philosophy itself, and of the “final cause” (one of the four Aristotelian causes, the other three being material, efficient, and formal, which constituted a full explanation of a thing).