challenge this premise—namely, that every visible object lies in a direction relative to the observer—by arguing that a person sees himself in a mirror, although his own self lies in no direction relative to him other than the direction opposite him. For, since he sees himself, yet his self does not reside in the mirror situated opposite him, he sees himself without his self being in any direction.

This, however, is a fallacy: what he sees is merely his own image. That image lies in a direction relative to him if the image is in the mirror and the mirror lies in a direction.