Logical Realism—A Tale of Two Theories*

This paper compares two theories of the nature of logic: Maddy’s, (2007, 2014a)—henceforth “Theory 1”—and Sher’s (1991, 2016)—“Theory 2”. The two theories share a significant element: they both diverge from the commonly held view that logic is grounded only in the mind (language, concepts, conventions, etc.). Instead, they argue that logic is crucially grounded in the world. But the two theories differ in significant ways as well. Most distinctly, one is an anti-holist, “austere naturalist” theory while the other is a non-naturalist “foundational holistic” theory. This methodological difference affects their questions, goals, orientations, the scope of their investigations, their logical realism (the way they ground logic in the world), their explanation of the modal force of logic, and their approach to the relation between logic and mathematics.