AAP 2026 CONFERENCE

Consider the following version of the Direct Argument: 

  a. Either the butler or the gardener did it.
  b. (And it may not be the butler.)
  c. So, if the butler didn’t do it, the gardener did.

According to material conditional interpretation of indicative conditionals, it is easy to explain why this is a great argument: Because it is truth-preserving. However, many, if not most, philosophers deny that the indicative conditional is the material conditional. But if it is not truth-preserving, then why is this a great argument? To answer this question, Boylan & Schultheis (2022) have recently defended the Qualitative Thesis, which has generally been taken to be a fundamental constraint on indicative conditionals. According to this thesis, the Direct Argument is knowledge-preserving.

The Qualitative Thesis: When you leave open A, the indicative conditional A > B is knowable if and only if the material conditional A ⊃ B is knowable (Boylan, 2024).

In this paper, I provide a counterexample to the Qualitative Thesis. But instead of just rejecting the Qualitative Thesis, I defend a qualified version of it that overcomes the problem with the original version by taking into account the ambiguity of conditionals.