Innocence verses Ignorance: Reading an Annotated Father Brown

I'm sure I've read almost all of the Father Brown mysteries, but it has been years.  Added an annotated version, and it certainly deserved a reread.
The first Father Brown story written and published was "The Blue Cross."  If you are unfamiliar with this story, Father Brown is able to recognize the famous thief Flambeau who is disguised as a priest.  He does so for a variety of reasons, but my favorite is when Father Brown because he "attacked reason...It's bad theology."  I wonder if Father Brown would be able to snoop out false priests and clergymen now by a similar test.
And this, by the way, is the great flaw in the recent BBC version with Mark Williams.  At first glance, it seemed like a great idea.  Though Mark Williams is too large of a man to really play the unassuming priest, in other ways he seems a perfect fit.  But if Father Brown's theology isn't sound, he isn't a good detective.
But I digress.  
In "The Blue Cross" both the thief Flambeau and the detective Valentin underestimate a simple priest's ability to recognize evil because what could someone who lives a celibate, religious life know of evil?  Father Brown reminds them, "Has it never struck you that a man who does next to nothing but hear men's real sins is not likely to be wholly unaware of human evil?"
The preface of my annotated edition quotes a story Chesterton tells in his autobiography of the idea of Father Brown's knowledge of evil coming from such an innocent source.  Father Brown was based off the real Father O'Connor.  This priest impressed two Cambridge undergrads with his knowledge of "things as Palestrina and Baroque architecture, but when the priest left the room one of them remarked: 
All the same, I don't believe his sort of life is the right one. It's all very well to like religious music and so on, when you're all shut up in a sort of cloister and don't know anything about the real evil in the world. But I don't believe that's the right ideal. I believe in a fellow coming out into the world, and facing the evil that's in it, and knowing something about the dangers and all that. It's a very beautiful thing to be innocent and ignorant; but I think it's a much finer thing not to be afraid of knowledge." 
To me, still almost shivering with the appallingly practical facts of which the priest had warned me, this comment came with such a colossal and crushing irony, that I nearly burst into a loud harsh laugh in the drawing-room. For I knew perfectly well that, as regards all the solid Satanism which the priest knew and warred against with all his life, these two Cambridge gentlemen (luckily for them) knew about as much of real evil as two babies in the same perambulator. 
And there sprang up in my mind the vague idea of making some artistic use of these comic yet tragic cross-purposes; and constructing a comedy in which a priest should appear to know nothing and in fact know more about crime than the criminals. "
Innocence is not the same thing as ignorance.  But how can a man be exposed to so much evil and yet remain innocent?  I wonder how Chesterton or Father Brown would react to the sex abuse scandals in the Catholic church?  I feel they would do so with some compassion for the fragility of men.  After all, Father Brown's primary goal in solving crime was to save the criminal from himself.  It makes sense that constant exposure to evil could corrupt a man's soul.
Interestingly, the Protestant church has plenty examples of the opposite effect.  We Protestants rarely confess our sins.  Often we are shield our children so much from evil that when it comes upon them, they are completely defenseless.  Josh Dugger comes to mind. The Christian musician Audrey Assad gave a testimony about her addiction to pornography.  She said that when she first stumbled on it, she didn't know what it was.  She literally had never even heard the word pornography before.
So, if neither ignorance nor knowledge create innocence, what do we do?  Well, Father Brown, with an eye on sound theology, to lean into the cross.  "The Innocence of Father Brown" is holiness.