The Quinean Assumption. The Case for Science as Public Reason

The status of scientific knowledge in political liberalism is controversial. Although Rawls argued that the noncontroversial methods and conclusions of science belong to the kind of reasons that citizens can legitimately call forth in public deliberation, critics have observed that the complexity and elaborateness of scientific arguments drive them away from the spirit of public reason, i.e., that which should reflect judgments that are the product of general beliefs and forms of reasoning found in common sense. In other words, scientific claims remain as inaccessible as esoteric or religious reasons. This paper contends that this objection can be met by introducing a crucial assumption, drawn from W. V. O. Quine and the ‘naturalized epistemology’ tradition: that scientific reasoning and everyday reasoning are not two different epistemic categories but rather form a continuum. The former is just a filtered or refined version of the latter. Accordingly, evidence-based scientific reasoning is common to all citizens, regardless of their actual acceptance of specific scientific claims. Following the Quinean Assumption, political liberals may argue that, unlike religious or esoteric sources of knowledge, scientific reasoning is the expression of a cognitive operation that is fundamentally shared across comprehensive doctrines and politically reasonable individuals.