If-Thenism and Fictionalism

ABSTRACTStandard theories treat A→C and A→D as equivalent when C and D coincide on A. However, Yablo's incremental conditional does not behave in this way. Consider the following: a = b→Fa. a = b→Fb.According to Yablo, the real content of is Fb and the real content of is Fa. In worlds where a = b is true, both and have the same truth-value. However, ‘Fa can come apart truth-value-wise from Fb in worlds where a isn't b.’ In this paper, I argue that this feature of Yablo's incremental conditional makes his if-thenism incompatible with fictionalism.