Orthogonality and Presuppositions. A Bayesian Perspective

Résumé En

This work focuses on the reasons why the projection prop- erties of presuppositional elements are not uniform. Presupposition pro- jection designates the fact that operators that suspend the truth of a proposition have no effect on the presupposition it is associated with. For instance, with Paul did not stop smoking, the main content (that Paul does not smoke) is canceled by the negation whereas the presupposition that Paul has been smoking is left untouched. It has been observed that projection is not uniform across the different expressions that convey a presupposition (its triggers), and a distinction between weak and strong triggers has emerged. It seems that this distinction correlates with an intuition of (non-)orthogonality, that is, of (non-)independence between the main content and the presupposition. I argue that this intuition is correct to some extent but has to be clarified. To this aim, I propose a Bayesian approach, which provides a more precise rendering of orthogonality.