Implicit arguments in situation semantics

.Most theories of grammar draw a fundamental distinction between arguments and adjuncts. The former are phrases selected by some predicate; the latter are phrases which are unselected, and which functions as "modifiers". Although the adjunct-argument distinction is a sharp one conceptually, it is well-known that certain classes of phrases do not pattern clearly with respect to it. This is so for phrases of source, path and goal, like those in (1), and for phrases of instrumentality and agency, like those in (2) and (3): (1)a. b. 12. (2)a. b. (3)a. b. John ran (from the house) (to the store) (along the river) Every boy (from Impanema) A trip (from the house) (to the store) (along the river) John cut the salami (with a knife) The destruction of the city (with rockets) John was seen (by Felix) The letter (by Felix) Such expressions appear to share properties of adjuncts and arguments alike, and have been referred to in the literature as optional or "implicit" arguments (Roeper (1983)). In this paper I present an analysis of implicit arguments within the framework of Situation Semantics (Barwise and Perry (1981a,b; 1983)) according to which these elements are neither arguments nor adjuncts in the usual sense. Rather they are phrases licensed by a form of extragrammatical "inference" involving knowledge about events and the relationships holding among them. In Situation Semantics, sentences or, more properly, utterances U- are taken to describe events e: