Viability is not a defining characteristic of personhood. Someone on dialisis or in the ICU on lifesupport is not "viable" on their own (they rely on someone else or something to be able to live) yet we all agree they are still a person while in this dependent and often helpless state. A child in the womb is fully a person at 22 weeks or 24 weeks or any other time it depends on mother.

Viability doesn't on its own determine personhood. Someone on dialsis is not "viable" on their own (they can not survive without assistance) yet we all agree they are still a person. A child in the womb is fully a person at 22weeks or 24 weeks or any other time.