Those who allow two parts to constitute a body appeal to the comparative ajsam (“more bodily” or larger). If one part is added to a composite and the result is called more bodily, they argue, the earlier composite must already possess bodyhood.
This reasoning infers the presence of a quality from an increase in its degree. Calling one object brighter than another ordinarily presupposes some brightness in both.
The reply asks whether ajsam compares technical bodyhood at all, or instead compares the size and bulk of things already considered bodies.