A. Solution

18. The answer to the other question is plain according to what was said above, d.1 nn.44-47, that created personhood states negation of actual dependence on something else as on the supposit of the nature, and also negation of aptitudinal dependence, which - as far as concerns the thing having the aptitude - would always be actual (as the separated soul would always depend on the body as far as concerns the soul’s natural aptitude); since therefore it is a contradiction for a nature to depend and not depend actually on an extrinsic person, and the nature’s being assumed is its actually depending with this particular dependence, it is a contradiction for it to be assumed and to have at the same time its own created personhood.

19. But those who would posit that created personhood states some positive nature or entity over and above the singular nature, and that for this reason it is repugnant for created personhood to be assumed but not so repugnant for the singular nature - they would have to look for some other cause why a person cannot be assumed [cf. n.8].

20. But what is here supposed [n.19] was rejected in d.1 n.26; and against it well proceeds the reason touched on [n.7] about the division of substance and accident and threefold substance.