A controversy has existed over the interaction of syntax and semantics in natural language understanding systems. According to theories of integrated parsing, syntactic and semantic processing should take place simultaneously, with the parsing process driven by a single rule base which contains both syntactic and semantic knowledge. This is in sharp contrast to traditional linguistic approaches to language analysis, in which syntactic and semantic processing are performed separately from one another, driven by completely separate sets of syntactic and semantic rules. This paper presents an approach to natural language understanding which is a compromise between these two views. It is an integrated approach, in the sense that syntactic and semantic processing take place at the same time. However, unlike previous integrated systems, the approach described here uses largely separate bodies of syntactic and semantic knowledge, which are combined only at the time of processing.