Conversational presuppositions: Presupposition as defeasible inference

In this paper, I will try to support the admittedly controversial claim that presuppositions are normally defeasible inferences, taking the lead from Levinson, Stephen C. 1983. Pragmatics. Cambridge: CUP., Simons, Mandy. 2013. On the conversational basis of some presuppositions. In A. Capone, F. Lo Piparo & M. Carapezza (eds), Perspectives on linguistic pragmatics, 329-348. Dordrecht: Springer, Macagno, Fabrizio & Alessandro, Capone. 2016a. Presuppositions as cancellable inferences. In K. Allan, A. Capone, I. Kecskes & Springer Dordrecht (eds.), 45-68; Macagno, Fabrizio & Alessandro. Capone. 2016b. Uncommon ground. Intercultural Pragmatics 13(2). 51-180. In passing, I will justify further some of the claims we made in Macagno, Fabrizio & Alessandro. Capone. 2016a. Presuppositions as cancellable inferences. In K. Allan, A. Capone, I. Kecskes & Springer Dordrecht (eds.), 45-68; Macagno, Fabrizio & Alessandro. Capone. 2016b. Uncommon ground. Intercultural Pragmatics 13(2). 51-180. I will also make a further attempt to explain those notions in a clearer way. Most importantly, I will capitalize on the distinction between potential and actual presuppositions, a distinction which may parallel the one between potential and actual conversational implicatures (see Levinson, Stephen C. 2000. Presumptive meanings. The theory of generalized conversational implicature. Cambridge Mass.: MIT Press; Levinson, Stephen C. 1983. Pragmatics. Cambridge: CUP; Huang, Yan. 1994. The syntax and pragmatics of anaphora. A study with special reference to Chinese. Cambridge: CUP.; Huang, Yan. 2014. Pragmatics. Oxford: OUP.). Levinson, Stephen C. 1983. Pragmatics. Cambridge: CUP. understands this distinction and assumes it is of importance, but, in my opinion, he does not sufficiently capitalize on this, as I want to do in this paper. Also, the terminology he uses is not exactly cast in these terms, but I think it is not unreasonable to borrow the distinction from the theory of generalized conversational implicatures, given that as Atlas, Jay. 2004. Presupposition. In L. R. Horn & G. Ward (eds), The Handbook of Pragmatics. Oxford: Blackwell, and Levinson, Stephen C. 1983. Pragmatics. Cambridge: CUP. say, there are many points of contact between conversational implicatures and conversational presuppositions.