A belief one has is safe if either (i) it could not easily be false or (ii) in any nearby world in which it is false, it is not formed using the method one uses to form one’s actual belief. It seems our mathematical beliefs are safe if mathematical pluralism is true: if, loosely put, almost any consistent mathematical theory is true. It seems, after all, that in any nearby world where one’s mathematical beliefs differ from one’s actual beliefs, one (...) would believe some other true, consistent theory. Focusing on Justin Clarke-Doane’s recent discussion, I argue the thesis that mathematical beliefs are safe given pluralism faces some obstacles. I argue (i) is true of mathematical belief given pluralism only if we deny plausible claims about the interpretation of non-pluralists who many of us could easily be. Unless strong metasemantic theses are true, it is plausible many of us could easily deny or refuse to believe a consistent and true mathematical theory we actually believe. Since philosophical arguments and controversies permeate the methodology of foundational mathematics, I argue we cannot confidently distinguish the methods we use in mathematics between worlds, thus raising doubts about (ii). (shrink)

I offer an interpretation of Carnap and Quine’s views on cognitive significance and insignificance. The basic idea behind their views is as follows: to judge an expression is insignificant is to recommend it not be used in or explicated into languages used to express truth-valued judgments in inquiry; to judge an expression is significant is to recommend it be used in or explicated into such languages. These judgments are pragmatic judgments, made in light of purposes for language use in inquiry. (...) For Carnap at least, these pragmatic judgments are non-cognitive. This basic idea is only a roughly correct statement of their views. This is because the details of the scientific languages they recommend for inquiry are necessary to understand their views and the way they understand their own views. Even so, I offer two reasons to suggest that this basic idea is worthy of our consideration today. First, it provides a conception of significance that captures the natural thought that epistemological concerns can lead us to consider expressions to be insignificant without requiring an objectionable form of verificationism. Second, if we appeal also to Carnap and Quine’s pluralistic attitude toward explication, we can make a pragmatic judgment that an expression is insignificant while judging it to be significant on a distinct explication of significance fit for describing and explaining natural language. (shrink)