According to two-dimensional semantics, the meaning of an expression involves two different "dimensions": one dimension involves reference and truth-conditions of a familiar sort, while the other dimension involves the way that reference and truth-conditions depend on the external world (for example, reference and truth-conditions might be held to depend on which individuals and substances are present in the world, or on which linguistic conventions are in place). A number of different two-dimensional frameworks have been developed, and these have been applied to a number of fundamental problems in philosophy: the nature of communication, the relation between the necessary and the a priori, the role of context in assertion, Frege’s distinction between sense and reference, the contents of thought, and the mind-body problem. Manuel Garcia-Carpintero and Josep Macia present a selection of new essays by an outstanding international team, shedding fresh light both on foundational issues regarding two-dimensional semantics and on its specific applications. The volume will be the starting-point for future work on this approach to issues in philosophy of language, epistemology, and metaphysics.