  The argument from predicate to property dualism moves in two steps, both controversial. The first claims that the irreducible special sciences, which are the sources of irreducible predicates, are not wholly objective in the way that physics is, but depend for their subject matter upon interest-relative perspectives on the world. This means that they, and the predicates special to them, depend on the existence of minds and mental states, for only minds have interest-relative perspectives. The second claim is that  psychology – the science of the mental – is itself an irreducible special science, and so it, too, presupposes the existence of the mental. Mental predicates therefore presuppose the mentality that creates them: mentality cannot consist simply in the applicability of the predicates themselves.