Your Metaphor or Mine: Belief Ascription and Metaphor Interpretation

Abstract

ViewGen, an algorithm and program for belief ascription, represents the beliefs of agents as explicit, partitioned proposition-sets known as environments. A way of extending View-Gen to the interpretation of metaphor, and in particular to the comprehension of metaphor within the belief spaces of particular agents, has been described elsewhere. The paper reports the further refinement and recent implementation of this approach, as well as summarizing the argument for the claim that ordinary non-metaphorical belief ascription and the transfer of information in metaphors can both be seen as different manifestations of a single environment-amalgamation process, one in which explicitly metaphorical amalgamations are triggered by "preference breaking " in the sentence being processed. This requires a consideration of the scoping of metaphor with respect to belief contexts, analogous to the scoping of quantification and definite descriptions with respect to such contexts. As a topic of ongoing and future work, the issue of mixed metaphor, of two distinct types, is briefly addressed. 1 ViewGen: The Basic Belief Engine A computational model of belief ascription is described in detail elsewhere [Wilks and Bien, 1979, 1983] [Ballim, 1987] [Wilks and Ballim, 1987] [Ballim and Wilks, in press] and is embodied in a prolog program called View-Gen. The basic algorithm of this model uses the notion of default reasoning to ascribe beliefs to other agents unless there is evidence to prevent the ascription. Perrault [1987, 1990] and Cohen and Levesque [1985] have also recently explored a belief and speech act logic based on a single explicit default axiom. As our previous work has shown for some years, the default ascription is basically correct, but the phenomena are more complex than are normally captured by an axiomatic approach. ViewGen also avoids certain counter-intuitive assumptions, such as the non-persistence of ignorance about any given proposition p [Perrault, 1990]. Also such systems