Indefensible Self-Defense Argument

The self-defense argument maintains that, even if a fetus is a person, (pre-viable) abortion on demand is morally permissible on the grounds that the fetus is using his mother’s body in an intimate way, and, in an unwanted pregnancy, without her ongoing consent.  According to the argument, this sort of use justifies lethal self-defense on the part of the mother against her unwanted fetus.  I produce a counterexample to one of the premises of this argument and show that it cannot be successfully revised.  I further show the underlying commitments of the self-defense argument lead to the absurd conclusion that a woman who has consensual sex that results in pregnancy thereby violates the fetus’ right to bodily autonomy and so such an act would be morally impermissible.  We thereby have good reason to abandon the argument.