No contexto dos problemas do predicado existencial:
Imagine checking off a list of assertions about Bill Clinton, to the effect that he is president, that he smiles a lot, that he is intelligent, that he is imprudent, that he exists. For the first four items your thought is a subject-predicate thought about a certain concrete entity, but when it comes to the fifth item your thinking suddenly goes second-order as you mentally invoke some suitable [property] to pin your existential thought upon.
McGinn C. , Logical Properties. Identity, Existence, Predication, Necessity, Truth, p. 18.