Reasoning with Generics Based on Truth-Conditional Semantics

Abstract

Generics have been analyzed in two main trends. In this paper, they are analyzed in the truth-conditional semantics. One major problem with previous truth-conditional analyses is that they did not make correct predictions on reasonable inferences, especially on inferences related to so-called graded normality. And so far negations of generics, which I call weak generics, have not been seriously handled In this paper, I propose a truth-conditional analysis which considers weak generics as well as strong generics and allows us to account for nonmonotonicity in reasoning with generics, and in doing this, I introduce the notion of minimal world/frame and constrain a frame with regard to each generic sentence including weak generics. It will be shown that weak generics may make a frame inconsistent, but they have significant effect only when they are exceptions to other generic sentences.