By Bruce P. Blackshaw

When Perry Hendricks’ impairment argument was first published in 2018, I was impressed that someone had come up with what seemed to be a novel argument for the immorality of abortion. Importantly, it wasn’t based on the moral status of the fetus. Instead, it used an uncontroversial moral claim—that deliberately inflicting fetal alcohol syndrome was wrong—and extrapolated this to abortion. The argument says, roughly, that since it is immoral to non-lethally impair a fetus (by giving it fetal alcohol syndrome), it must also be immoral to lethally impair a fetus, since lethal impairment is more severe than non-lethal impairment.

I was, however, skeptical of what is called the ‘ceteris paribus’ clause in Perry’s impairment principle, which stated that impairing by abortion was also wrong only if all other things were equal. I didn’t think all other things were equal, and wrote two replies explaining why. Perry replied to my criticism, but I wasn’t convinced.

I kept thinking it over for a few weeks, and while working on a paper that referenced Don Marquis well-known ‘future-like-ours’ argument against abortion, I realised that this could be used to strengthen the impairment argument. The future-like-ours argument claims that killing us is wrong because we have a future containing valuable things that we would be deprived of. Similarly, Marquis argues abortion is wrong for exactly the same reason—the fetus also has a future containing things of value, a future just like our own. It seemed that the ‘ceteris paribus’ clause could be dropped and replaced with a much narrower condition that could appropriate Marquis’ reasoning. Once the clause is dropped, most objections to the impairment argument dissolve, thereby strengthening the impairment argument.

I thought it would be a good idea to contact Perry and explain my thoughts, with the idea of perhaps writing a joint paper if he agreed on the approach. Perry very kindly considered my proposal, and agreed to cooperate to develop the idea further. We are pleased with the result. In our view, the elimination of the ‘ceteris paribus’ clause strengthens the impairment argument considerably. There have been several responses criticising the argument, all focusing on this clause, and so the revised impairment argument is able to deal with them. It will be interesting to see how these critics respond.

Paper title: Strengthening the Impairment Argument Against Abortion

Author(s): Bruce P. Blackshaw, Perry Hendricks

Affiliations: University of Birmingham, United Kingdom. Purdue University.

Competing interests: None