Problems in logical form

Most current theories of natural-language processing propose that the assimilation of an utterance involves producing an expression or structure that in some sense represents the literal meaning of the utterance. It is often maintained that understanding what an utterance literally means consists in being able to recover such a representation. In philosophy and linguistics this sort of representation is usually said to display the "logical form" of an utterance. This paper surveys some of the key problems that arise in defining a system of representation for the logical forms of English sentences and suggests possible approaches to their solution. The author first looks at some general issues relating to the notion of logical form, explaining why it makes sense to define such a notion only for sentences in context, not in isolation, and then discusses the relationship between research on logical form and work on knowledge representation in artificial intelligence. The rest of the paper is devoted to examining specific problems in logical form. These include the following: quantifiers; events, actions and processes; time and space; collective entities and substances; propositional attitudes and modalities; and questions and imperatives.