 Robert Stalnaker has articulated such an externalist interpretation of the 2D framework in a series of influential papers spanning some thirty years. He was the first to introduce 2D matrices to specify what is communicated in situations where conversational partners are partly ignorant or mistaken about the nature of the objects, kinds or properties their words pick out (1978), and he later extended his 2D framework to characterize the content of certain thoughts and attitude attributions (1981; 1987; 1988). In both cases, the 2D framework is used to define “diagonal” intensions that reflect the subject’s partial understanding of which objects, kinds or properties her words and thoughts represent. These diagonal intensions are not meanings or semantic values, since they do not figure in a compositional semantic theory and they do not reflect conditions for conceptual or linguistic competence. The only meaning of an expression on this account is its ordinary “horizontal” intension. In effect, Stalnaker’s 2D matrices represent different meanings that an expression could have had if it had occurred in different empirical circumstances. This “metasemantic” interpretation of the 2D framework contrasts sharply the “semantic” interpretations favored by G2D theorists like Jackson and Chalmers (Stalnaker 2001, 2004).