With the fourth scene we get another radical twist a story: we now learn the real reason the Duke left the city is to return incognito.
At this point it’s not clear precisely why he wishes to do this. Notice the Duke’s initial statement in this scene dismisses the possibility of a love affair: he did not go to see the Friar to succumb to the burning passions of youth. But why does father Thomas bring up the subject of a love affair? Is it not perhaps an indication that the Duke has snuck off before, perhaps to dabble a little? Must we not ask why the laws related to sexual morality went unenforced? Could it be that the Duke simply didn’t care? That seems unlikely given all the trouble he will go through in this play. Perhaps it’s that he would not enforce the morality he did not ascribe to.