Interrogating Evidential Pluralism
A Critical Comparison of Approaches to Incorporating Mechanisms in Evidence Synthesis
DOI:
https://doi.org/10.5195/pom.2026.316Keywords:
Evidential pluralism, Evidence synthesis, Methodology, Realist review, EBM+Abstract
Different versions of evidential pluralism offer contrasting accounts of how evidence of mechanism should be combined with evidence of association for the purposes of causal inference. This paper explores the philosophical learnings from an empirical application of two approaches—formal Evidential Pluralism (developed relatively recently and associated with Williamson) and traditional evidential pluralism (which has a long history in philosophy of science; its more recent iterations are associated with, among others, Russo and Illari). These approaches are contrasted using a complex and contested empirical case: a heterogeneous body of studies on face mask efficacy, offering evidence of both association and mechanism. The findings raise questions about the adequacy of formal Evidential Pluralism for questions of causal inference in complex healthcare contexts.
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