  One possibility is to deny that attitude verbs designate relations when complemented by that-clauses, and to claim that they rather make a syncategorematic semantic contribution. Under one approach, that-clauses in attitude ascriptions designate propositions which serve to “measure” attitudes conceived of as mental particulars (Matthews 1994). It is not clear that this view will be immune to substitution and objectivization problems. See Moltmann (2003) for further discussion.