If the dead do not know what the living are doing, how is it that the martyrs can provide aid to those that pray, and thus show that they take an interest in the affairs of men? For it is certain that, when the barbarians were attacking Nola, the confessor Felix (whom you piously love as he rests among you) appeared not only through what resulted from his aid, but that he was actually seen by men.
This is interesting because he's asking a timeless question, but then he's very much putting it into the modern context of a recent encounter with a martyr.