Metaphor and Artificial Intelligence: Why They Matter to Each Other

Why is Artificial Intelligence concerned with metaphor, and what special contributions can AI offer to metaphor research? This chapter will indicate why AI needs to study metaphor and will outline what AI has been contributing to the illumination of metaphor, whether it is processed by artefacts or by the human mind. Specific contributions AI research on metaphor that one can already point to, and that will be addressed to varying extents in this chapter, include the following: creation of detailed mechanisms for reasoning within the terms of the source-domain in a metaphor, in order expand the relevance of known source-target mappings; increased emphasis on uncertainty and gradedness in metaphorical reasoning; a richer view of overriding (source-over-target as well as target-over-source); mechanisms for exploiting context; important steps towards integration with metonymy interpretation; some emphasis on disanalogy and a limitation of the role of parallelism between source and target; the usefulness of reversed transfers (transfers from source domain to target domain); the importance of nonassertional metaphor; increased doubt about whether the notion of a “domain” is actually important and well-founded; and clarification of ways in which literal meaning can be involved in metaphor interpretation. The plan of the chapter is as follows. The next section will make some observations about AI, explain why metaphor is important to applications-oriented aspects of AI, and indicate why, in general terms, AI can make distinctive contributions to the study of cognition as a whole, metaphor included. Then a new section will sketch five different, relatively recent AI research works on metaphor. This is to set the scene for the following section, which will discuss specific contributions of AI to metaphor research. The issues will be summarized in a brief concluding section. The chapter does not attempt to survey AI research on metaphor completely or to provide a history of this work, despite the fact that AI has long had an interest in metaphor (cf. e.g. Carbonell, 1980, 1982 ; Norvig, 1989; Russell, 1976, 1985 ; Way, 1991; Weber, 1989; Weiner,