Presupposition-cancellation and metalinguistic negation: a reply to Carston

This is a response to Carston's critique of my account of presupposition-ca ncellation. While accepting her demonstration that (contra 'On Horn's dilem ma') presupposition-cancellation does not involve a linguistically encoded contradiction, I show that this is nevertheless consistent with the account of presupposition proposed in Burton-Roberts I993/7 In fact, Carston's and my accounts of presupposition-cancellation both treat it as involving a pr agmatically derived contradiction. I also reconsider the nature of so-calle d 'metalinguistic negation', arguing against Carston that there is a specia l use of negation (!MN) which involves a use-mention mix and a pragmaticall y derived contradiction, and is non-truth-functional. I show that, although !MN is echoic, not all echoic negations are examples of !MN.