 In spite of the ontological assumptions behind the Isagoge and the lesser, extant commentary on the Categories, Porphyry’s very disclaimers, his avoidance of the deep questions about the ontological status of genera and species—whether they exist or depend on thought; and if they exist, whether they are bodies or incorporeal; and if the latter, whether they are sensible items or exist separately from such—no doubt contributed to the ease with which these works were taken into obligatory school readings for centuries. Thus, his non-committal formulations of them helped make these works the most lasting part of his legacy in West.