 (I use the word ‘reference’ here roughly the way Frege used ‘Bedeutung’ after 1892. But it could also be taken the way Lewis uses ‘extension’. The differences are significant, but they do not matter for present purposes.) To avoid confusion, we should call this the principle of compositionality of reference, and  (C)  the principle of compositionality of meaning; when I speak of compositionality unqualified, what is meant is always the latter. Since the arguments in favor of compositionality tend to be based on general considerations about linguistic understanding—which, I shall suppose amounts to nothing more or less than understanding what linguistic expressions  mean[4]—proponents  of (C\(_{\textit{ref}}\)) have a choice to make. They can advocate (C\(_{\textit{ref}}\)) on different grounds or they can claim that an appropriate theory of the sort that assigns (relative to a variety of contextually determined  factors[5])  references to expressions can serve as a theory of meaning.