Among the philosophical writings of the prolific Maphrian Barhebraeus is the Book of the Pupils of the Eye, which is concerned with logic (or dialectics). In it, Barhebraeus works through several earlier treatments: Porphyry’s Eisagoge and a number of Aristotelian texts. The critical edition given here, based on four Berlin manuscripts (discussed in the introduction), is supplemented by a partial translation into German (the introduction and the part on Porphyry). Finally, the author supplies several lexical observations on certain Syriac words. This volume will be of definite interest to readers who study the later reception of Greek, especially Aristotelian, philosophy, and to students and scholars of later Syriac literature generally.