فَلِاسْتِحَالَةِ اكْتِسَابِ مَا لَيْسَ قَائِمًا بِمَحَلِّ الْقُدْرَةِ
An effect not subsisting in the locus of capacity cannot be acquired in that same manner.
On this account, human acquisition attaches to an action in the appropriate locus of the servant’s capacity. Treating pain in another person or breakage in an external piece of glass as directly acquired in precisely the same way raises a problem.
Contrast: A person’s hand movement is voluntary; the pain felt in someone else’s body is not that person’s own voluntary movement. This does not erase moral responsibility for causing harm; it clarifies different forms of attribution.