Alice ter Meulen is Professor of Philosophy and of Linguistics at Indiana University, Bloomington. Her research interest is in the interface of logic, language and metaphysics, and has been concerned with mass and amount terms in Montague grammar, and the semantics of tense and aspect in a dynamic system and its interaction with pronominal reference. Address: Indiana University, Department of Philosophy, Sycamore Hall 026, Bloomington, IN 47405, USA. E-mail: atm@phil.indiana.edu