In a much-discussed article, Gillian Russell claimed that “logic isn’t normative”: according to her, the usual bridge principles for logic are just derived from general principles for truth and falsity, such as “believe the truth” or “avoid falsity.” For example, we ought to believe tautologies just because we ought to believe the truth. Russell argues that this rejection of logical normativity can avoid the collapse objection for logical pluralism, which typically presupposes the normativity. In the last part of his new (...) book Logical Pluralism and Logical Consequence, Erik Stei responds that even if logic is normative in this weak derivative sense, the collapse objection re-emerges. His main point is that the collapse argument can still work even if the bridge principles are derivative (they just need to be true). In this paper I will argue against Stei’s point. I will show that there is a possible strategy which maintains the derivative normativity of logic and provides a non-trivial logical pluralism. The key to my approach is the possibility of having different normative sources for different logics. I will argue that the distinction between classical and relevant logic can be understood in this way. (shrink)

In this paper, I critically examine the monist interpretation of the logic-as-model view that Erik Stei puts forth in Logical Pluralism and Logical Consequence. I will argue that, in addition to the three dimensions presented in the book, there is a fourth dimension on which pluralism in logic could arise, namely epistemological pluralism. An example of such a form of pluralism is model pluralism, being the idea that we need multiple models to fully account for the subject matter of logic. (...) Such a form of pluralism is well-recognized and widely acknowledged in (model-based) science. I argue that if we endorse the logic-as-model view, then we should also recognize such a form of model pluralism in logic. While model pluralism is consistent with metaphysical monism — the idea that there is ultimately only one extra-systemic logical consequence relation — it does put pressure on the idea that there is one uniquely best model that fully captures that phenomenon. (shrink)