"The Hammer of God" is a familiar story to me, both because I've read it in The Innocence of Father Brown and because I've seen another adaptation of it in the 1974 series with Kenneth More. While the new series has higher production values and is more entertaining, this episode (in my estimation) missed the main point of the story in its adaptation.
But first, what the new series gets right: Father Brown. Mark Williams (or Sir John Middleton from the new Sense & Sensibility, for those of you who watch Masterpiece) is nearly perfect in translating the character of Father Brown from the page to the screen. He is believable both as the buffoon and as the brain. He is believable as a priest. And, as I said, the production values for this show are much better than the earlier series. It's hard to tell from just one episode (which happens to be the first one) what all will happen, but it appears that the series' creators are working to situate Brown in a village context with recurring characters, at least more than Chesterton does. (This, to me, is one place where the Father Brown stories lack. There are some recurring characters, but they're business associates--ones he meets and has dealings with through crime-solving.) There is also an interesting choice to make Valentine the village inspector, suggesting that the relationship between Father Brown and the inspector, which was unexpectedly cut short in Chesterton's originals, might be allowed to develop onscreen. (Although I will say that it's baffling to begin the series with "The Hammer of God" and not "The Blue Cross," which is a later episode in the series.)
Before I get to what I think the episode got wrong, there's an important point to be made about Chesterton's Father Brown stories. It's that the stories are not that interesting as mystery stories. They're clever, to be sure, and they're entertaining, but they're not mysterious. There's a formula, and it works almost without fail: the person with the bad idea does the bad thing. Why? Because Chesterton wasn't really writing mystery stories: he was writing theological reflections on the human heart in the guise of detective stories. Where do bad ideas take us if we allow them to lead us anywhere? (This notion that ideas are powerful is described in detail in another of Chesterton's fictions, The Man Who Was Thursday. One of the policeman in the story says, "The work of the philosophical policeman . . . is at once bolder and more subtle than that of the ordinary detective. The ordinary detective goes to pot-houses to arrest thieves; we go to artistic tea-parties to detect pessimists. The ordinary detective discovers from a ledger or a diary that a crime has been committed. We discover from a book of sonnets that a crime will be committed. We have to trace the origin of those dreadful thoughts that drive men on at last to intellectual fanaticism and intellectual crime.") Find the bad idea, you've found the criminal, at least in a theological sense. And in Father Brown, the theological sense is embodied literally, physically.
Okay, so where did "The Hammer of God" go wrong? It made it too simple for viewers to distance themselves from the perpetrator. (Spoilers ahoy!) The murderer in both stories is the Anglican vicar, who from the view of his high place at the church, sees his brother and hurls a hammer from above. The motive, however, is very different, and the character is much less sympathetic on the screen. In the story, the vicar moves to blame the person with a mental disability because he can't feel the pain of the noose, should he be hanged for the crime. (Admittedly, this is problematic in its own right, but perhaps not out of line with beliefs of the time.) In the TV episode, the vicar seeks to blame the godless blacksmith, and not just because the hammer was his, and not just because he curses the vicar's church, and not just because he doesn't like him, but because the vicar loves the blacksmith's wife. So we add two more commandments broken to the "Thou shalt not murder" broken by the hammerstroke. But perhaps most puzzling is the real motive given for the murder (one could contend that blaming the blacksmith and claiming his wife was a convenience afforded by the circumstances he created accidentally, not premeditated). The real motive given is intolerance. The vicar says something like, "I could forgive my brother anything--drunkenness, lust, greed--but not that," referring to the homosexual act he witnessed from above. Aside from needlessly perpetuating stereotypes (and going off script from the source material), this motive derails the purpose for the story, which is a lens for introspection. Rather than a meditation on pride, it is a condemnation of something that, in the eyes of the viewer, is already deemed condemned. It's preaching to the choir.
The Father Brown stories usually do two things: they present us with a winsome character dispensing the sacraments of the Church (usually forgiveness, which is why the police are seldom involved in apprehending the criminal--Father Brown in many cases leaves the criminal to God because he's in the business of saving souls, not solving crimes), but they also present us with the reality that we have often been in the place of the criminal. The titular Secret of Father Brown (a later story collection) is that he can get to the heart of solving crimes because his own heart is so debased that he understands what it's like to be the criminal. (In other words, the root of his secret is original sin.) This is illustrated in "The Hammer of God." When Brown confronts the vicar, he gives a very strange detail:
He [the man who committed the crime] thought it was given to him to judge the world and strike down the sinner. He would never have had such a thought if he had been kneeling with other men upon a floor. But he saw all men walking about like insects. He saw one especially strutting just below him, insolent and evident by a bright green hat—a poisonous insect.After just a bit more revelation, the vicar realizes "thou art the man." The vicar asks, "How did you know that his hat looked like a green beetle?" The secret that is in the other collection made so explicit is on full display here: Father Brown is able to discuss the green beetle hat because he has thought the same.
The vicar in "The Hammer of God" is not a model for the reader or the viewer, but as I said, he's much less sympathetic in the show. It's too easy to pass judgment on the bad clergyman and leave it at that. "A bad man gets what he had coming to him. Delicious! What's for dessert?" But that exempts us from the much harder work of saying, "In what ways have I gone to my high place and looked upon the beetle? In what ways is Father Brown's secret my secret?" In this way I think "The Hammer of God" episode missed an opportunity to converse with the viewer in the way the source material converses with the reader.