Common Problems of Plausibility and Probabilism

Abstract

In this response to Allen and Pardo’s Relative Plausibility and Its Critics (available at: https://ssrn.com/abstract=3179601), I argue that while relative plausibility presents certain advantages over probabilism, it also fails to avoid several problems that the authors attribute to probabilism. I note that relative plausibility can be understood as probabilism under certain constraints that characterize a typical trial. I then argue that two of Allen and Pardo’s central problems with probabilism—the absence of an objective means for measuring the strength of evidence and the conjunction problem—apply to both probabilism and relative plausibility, although neither problem poses a serious threat to accuracy. I conclude that each theory, despite these problems, is useful for certain purposes—relative plausibility better models how advocates present cases and how jurors process information; probabilism serves as a valuable tool for modeling relevance and prejudice.

Keywords: evidence, proof, epistemology, probability, plausibility, conjunction problem