Abstract

The theories that form the heterogeneous family of two‐dimensional or 2D semantics are rooted in the tradition of possible‐worlds semantics made popular by Saul Kripke and David Lewis. Advocates of 2D semantics agree that recognizing a dependence of truth on fact is not enough. Advocates of two‐dimensional semantics share a second trademark idea. They agree that the familiar apparatus of worlds‐cum‐intensions can be modified so as to capture both the dependencies they see. The commitments of all 2D theories can basically be captured by one and the same formal framework of worlds‐cum‐intensions. David Kaplan's semantics aims to cover pure indexicals such as 'today' alongside impure indexicals such as 'you' and demonstratives such as 'this'. Kaplan starts off with two 'obvious principles': The referent of an indexical systematically depends on the respective context; and Indexicals are directly referential.