Semantics is the systematic study of linguistic meaning. The past fifty years have seen an explosion of research into the semantics of natural languages. There are now sophisticated theories of phenomena that were not even known to exist mere decades ago. Much of the early work in natural language semantics was accompanied by extensive reflection on the aims of semantic theory, and the form a theory must take to meet those aims. But this meta-theoretical reflection has not kept pace with recent theoretical innovations. The aim of this volume is to re-address these questions concerning the foundations of natural language semantics in light of the current state-of-the-art in semantic theorizing. The volume addresses a range of foundational questions about formal semantics: what is the best methodology for semantic theorizing, and should experimental techniques play a crucial role? How should we understand the use of formal tools such as model theory, and are there better formal alternatives? How should we think about compositionality? What does semantic theory tell us about the language faculty or linguistic competence? What are the advantages of dynamic semantics? How do formal semantic theories relate to philosophical notions of context, content, interpretation, and propositions?