A Solution to the Toxin Puzzle and to Sorensen's "Strengthened Prediction Paradox"

Ken Levy
Rutgers University

Roy Sorensen once offered an epistemological solution to the "Surprise Exam Paradox" or "Prediction Paradox" (henceforth, "PP"). Later, however, Sorensen and retracted his epistemological solution to PP. He did so because he claimed to have realized that we can make PP immune to an epistemological solution simply by eliminating from it a certain epistemological assumption that, it turns out, is really not essential to it. Because PP-minus-this-epistemological-assumption is no longer subject to an epistemological solution, Sorensen argues that PP-minus-this-epistemological-assumption is really a stronger version of the very same paradox embodied by PP. Sorensen naturally refers to this stronger version of PP simply as the "Strengthened Prediction Paradox" (henceforth "SPP"). It remains Sorensen's current position that even if the weaker version of PP (i.e., PP with the epistemological assumption) is subject to an epistemological solution, the philosopher's task is not over. SPP (i.e., PP without the epistemological assumption) still demands a solution.

Whether or not SPP is stronger than PP and whether or not SPP is a stronger version of the same paradox embodied by PP are both interesting questions. I shall not, however, discuss either of these in my paper. Rather, I shall (merely) perform the task of solving SPP. And I shall do this by solving the fundamental problem upon which Sorensen predicates SPP--namely, Gregory Kavka's "Toxin Puzzle".