Two-Dimensional Semantics – the Basics

‘Two-dimensional semantics’ denotes a family of semantic theories rooted in intensional semantics, held together by shared general ideas, yet divided by deep divergences in semantic aims and philosophical aspiration. 2dtheorists agree that our sentences’ truth-values vary with what the facts are, as well as with what the sentences mean. To model this twofold dependence of truth on fact and meaning, 2d-semantics assign our expressions intensions of more than one kind. The resulting formal framework, common to all 2d-sematics, distinguishes one dimension of actual worlds and primary intensions from a second dimension of counterfactual worlds and secondary intensions. (Hence two-dimensionalism.) These formal similarities often obscure the deep conceptual rifts between different interpretations of the 2dframework. Kaplan interprets it to capture context-dependence, Stalnaker understands it to model meta-semantic facts, and Chalmers construes it to display the epistemic roots of meaning.