And herein is a proof that God has given the art of divination not to the wisdom, but to the foolishness of man. No man, when in his wits, attains prophetic truth and inspiration; but when he receives the inspired word, either his intelligence is enthralled in sleep, or he is demented by some distemper or possession. And he who would understand what he remembers to have been said, whether in a dream or when he was awake, by the prophetic and inspired nature, or would determine by reason the meaning of the apparitions which he has seen, and what indications they afford to this man or that, of past, present or future good and evil, must first recover his wits. But, while he continues demented, he cannot judge of the visions which he sees or the words which he utters; the ancient saying is very true, that "only a man who has his wits can act or judge about himself and his own affairs." And for this reason it is customary to appoint interpreters to be judges of the true inspiration. Some persons call them prophets; they are quite unaware that they are only the expositors of dark sayings and visions, and are not to be called prophets at all, but only interpreters of prophecy.
In the eyes of Luke's Greco-Roman readers this may give Peter a prophetic like role and underscore his authority all the more (what I think is one of the purposes of Peter's first missionary speech in Acts). I wonder what Rick Strelan has to say about this in his book Strange Acts?