a single name, not through mere equivocation, but in virtue of a single meaning, such as the name “human being.” For neither of you doubts that its application to Zayd and Amr conveys a single meaning that exists. That existing meaning must either be accessible to sense perception or not. If it lies beyond the reach of the senses, then investigation has brought forth from sense-perceptible things something that is not sense-perceptible—and this is all the more remarkable.

If, however, it is sense-perceptible, then it necessarily has a position, a location, a definite magnitude, and a definite quality. It cannot be perceived—or even imagined—otherwise. For everything perceived by the senses and everything imagined necessarily has some determinate attribute of this kind. If that is so, it cannot correspond to anything not sharing that attribute, and therefore cannot be predicated of many individuals who differ in that respect. Thus, the human being, considered as one in reality—or rather, in terms of his fundamental essence, which does not vary across the many—is not perceptible to the senses, but is purely intelligible. The same holds for every universal.”

He said: “Perhaps one of them might say, ‘A human being is a human being only insofar as he has bodily parts—a hand, a foot, an eye, and an eyebrow—and insofar as he is such, he is perceptible to the senses.’ We would then draw his attention to this and say, ‘The same holds for every