Abstract
Preventive solutions for the paradoxes lead to the inexpressability of the adequacy conditions for the representation of truth within the system. Davidsonian theories of truth presuppose an understood language (for the background theory) which should permit the expression of the solutional principles for the paradoxes. The suitability of languages for this aim is tested by inferential validity paradoxes. They necessitate the introduction of an inner and an outer truthpredicate. For the paradoxes, two different types of circularity, often wrongly identified, have to be distinguished. For Davidsonian theories of truth, non-two-valuedness, different versions of convention T and "principled openess" of the background theory have to be postulated.