Chapter 12 argues that nothing in creation exists for itself alone. Human beings, their senses, and even their embodied design are oriented toward the partner rather than completed within the isolated self.
That makes individualism more than a social mistake. It becomes a false reading of reality. The self is real, but it is not self-sufficient.
This also gives a theological base for why radical autonomy feels spiritually thin. We were not made to become more ourselves by sealing ourselves off, but by finding the relationships our design is pointed toward.