Karttunen observes that a presupposition triggered inside an attitude ascription, can be filtered out by a seemingly inaccessible antecedent under the scope of a preceding belief ascription. This poses a major challenge for presupposition theory and the semantics of attitude ascriptions. I solve the problem by enriching the semantics of attitude ascriptions with some independently argued assumptions on the structure and interpretation of mental states. In particular, I propose a DRT-based representation of mental states with a global belief-layer and a (...) variety of labeled attitude compartments embedded within it. Hence, desires and other non-doxastic attitudes are asymmetrically dependent on beliefs. I integrate these mental state representations into a general semantic account of attitude ascriptions which relies on the parasitic nature of non-doxastic attitudes to solve Karttunen’s puzzle. (shrink)