Abstract

Categorisation models of metaphor interpretation are based on the premiss that categorisation statements and comparison statements are fundamentally different types of assertion. Against this assumption, we argue that the difference is merely a quantitative one: ‘x is a y’ unilaterally entails ‘x is like a y’, and therefore the latter is merely weaker than the former. Moreover, if ‘x is like a y’ licenses the inference that x is not a y, then that inference is a scalar implicature. We defend these claims partly on theoretical grounds and partly on the basis of experimental evidence. A suite of experiments indicates both that ‘x is a y’ unilaterally entails that x is like a y, and that in several respects the non-y inference behaves exactly as one should expect from a scalar implicature. We discuss the implications of our view of categorisation and comparison statements for categorisation models of metaphor interpretation.