In 1986, Van Rijsbergen suggested a model of an information retrieval system based on logic. We have advocated in earlier work that a logical approach should be based on a theory of information, Situation Theory, which provides a powerful range of concepts, and is useful for modelling documents and queries for the purpose of information retrieval. We also showed that Situation Theory provides a framework to represent different types of information retrieval models, thus allowing speculation on their properties and their characterization language. This paper is an essay to convince the reader that Situation Theory presents many characteristics that are both adequate and appropriate for the modelling and the study of information retrieval.