post by Paul Kelleher
Philosophical argumentation is a wonderful thing. It promotes clear thinking about the structure and substance of lines of reasoning, and it helps to locate problematic logical gaps. Sometimes, however, it is not philosophical argument that identifies the gaps, but rather our common sense. Sometimes, we just know there's a mistake somewhere, even if philosophical argument presents itself as ironclad. Consider The Surprise Test Paradox:
A teacher announces that there will be a surprise test next week. A student objects that this is impossible: “The class meets on Monday, Wednesday, and Friday. If the test is given on Friday, then on Thursday I would be able to predict that the test is on Friday. It would not be a surprise. Can the test be given on Wednesday? No, because on Tuesday I would know that the test will not be on Friday (thanks to the previous reasoning) and know that the test was not on Monday (thanks to memory). Therefore, on Tuesday I could foresee that the test will be on Wednesday. A test on Wednesday would not be a surprise. Could the surprise test be on Monday? On Sunday, the previous two eliminations would be available to me. Consequently, I would know that the test must be on Monday. So a Monday test would also fail to be a surprise. Therefore, it is impossible for there to be a surprise test.”
But obviously logic does not make it impossible for the teacher to throw a surprise test. Indeed, do you know what would make a surprise test an absolute certainty? Yep, that's right: if all the students accepted the seemingly ironclad line of reasoning presented above. If they all believe a surprise test is impossible, they will all be in a rude awakening when they don't study for it and then find blue books on their desks on Wednesday.
The lesson here is that one's intellect must always be on guard, even against seemingly airtight philosophical argumentation. Common sense always retains a key role, even while it itself undergoes continuous scrutiny. That's our predicament.
All this leads me to be less sanguine than Bill about a recent paper in Journal of Medical Ethics by Alberto Giubilini and Francesca Minerva that defends infanticide. Bill clearly states that he wishes to "defend Giubilini and Minerva's arguments, while disagreeing strongly with their conclusions." In particular, he says that "G & M are doing what ethicists are supposed to do: pursuing ethical arguments to their conclusions." In G & M's case, that conclusion is this:
[W]e argue that when circumstances occur after birth such that they would have justified abortion, what we call after-birth abortion should be permissible.
However, given the lesson of the Surprise Test Paradox, there is another thing the authors could have concluded. They could've said:
We have constructed a very strong argument for the conclusion that post-birth abortion is permissible. If that conclusion is false, then (1) there must be a problem with one of our premises, or (2) there must be a problem with the logical structure of the argument. We do not find either sort of problem, although it is of course possible one exists. We do not wish to advocate for permitting infanticide (at least not yet). But that seems to be where the argument leads. Evidently, those who oppose this controversial conclusion have some work to do.
Instead, the authors chose to declare--assert--that that infanticide really is permissible. If I sit here and declare that they should have deferred more to common sense, am I thereby claiming that I have a more highly evolved common sense than they do? I guess so. But at least I'll be prepared for Wednesday's surprise exam.
(I'll post Monday on what I do think is a clear substantive flaw in M & G's argument.)