Strengthening the impairment argument against abortion.

Perry Hendricks' impairment argument for the immorality of abortion is based on two premises: first, impairing a fetus with fetal alcohol syndrome (FAS) is immoral, and second, if impairing an organism to some degree is immoral, then ceteris paribus, impairing it to a higher degree is also immoral. He calls this the impairment principle (TIP). Since abortion impairs a fetus to a higher degree than FAS, it follows from these two premises that abortion is immoral. Critics have focussed on the ceteris paribus clause of TIP, which requires that the relevant details surrounding each impairment be sufficiently similar. In this article, we show that the ceteris paribus clause is superfluous, and by replacing it with a more restrictive condition, the impairment argument is considerably strengthened. © Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.