Instrumental with and use: modality and implicature

I present an analysis of the instrumental elements with and use, as in Betty cut the cake with a knife. A variety of evidence indicates that with and use do not make the same semantic contribution, casting doubt on the theory that these elements introduce the thematic role Instrument. For use, I adopt the analysis in Rissman (to appear): use expresses modal, goal-related content. For with, a modal reading may be implicated but is not entailed, explaining a variety of contrasts between with and use. The implications of this analysis for a theory of thematic roles is discussed.