Reduction Within a 2-D Framework

David Chalmers attempt to model core features of Fregean senses within a two-dimensional framework provides the resources to mimic at least some of the features presented above, so that a similar explication in terms of the 2-D framework can be given. On this view, what has here been called a conceptual difference, turns out to be an epistemological difference - a difference in epistemicaUy defined primary intensions of expressions. Let me, first, introduce the core ideas of Chalmers theory, then apply it to the case of reduction and finally hint to two problems that seem to occur within the framework. The summary to follow draws heavily 

can we decide between the two The proposal offered above is less committal in the sense that it does not commit one to a particular notion of Fregean senses, like Chalmer s 2-D framework does. If sparse commitment translates into quality, the framework proposed above is advantageous, especially since everyone who endorses 2-D semantics is free to endorse it, or a 2-D version of it, as well. (I guess that similar arguments work for algorithm-based, or procedural semantic theories of Fregean senses.) 

But there is more to be said primary intensions are described in purely epistemic vocabulary. This feature is, in the context of explicating a notion of reduction, highly problematic, because it blocks a way to explain the cognitive or epistemic differences between reduced and reducing item. Since pragmatic and alternative cognitive accounts suffer from a structurally similar problem, I will turn to these first and then close with a critical note on this point. 

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