The SIA Can't Just Go with the FLO

Hendricks (2018) has defended an argument that abortion is (usually) immoral, which he calls the impairment argument. This argument purports to apply regardless of the moral status of the fetus. It has recently been bolstered by several amendments from Blackshaw and Hendricks (2021a; 2021b). In this paper, three problems are presented for their Strengthened Impairment Argument (SIA). In the first, it is observed that even with the new modifications the argument, contrary to their insistence, does seem to depend on Marquis' argument. In order for it not to do so, they would need to provide some other plausible reason why impairing a fetus is wrong that persists in cases of abortion. Because of the restrictions regarding what reasons can be used, they are not entitled to stipulate that some plausible reason can be found. In the second section, the use of an over-ridingness caveat - the most recent modification - is scrutinised. This is shown to either beg the question about the permissibility of abortion by assuming that opposing reasons are insufficient in most cases, or require an entirely separate argument to establish that such reasons are insufficient. Thirdly, I observe that the principle utilised in the latest version of the argument fails to account for undercutting reason, which suggest that the principle, in its current form, is false.