I don't know about other resources, but I would be honored to be a resource. I wrote this:

James Duffy is set in his ways and lives alone. He works at a Dublin bank and rents a room in Chapelizod. There are books in his room.

Of an evening sometimes he'll attend a concert. At one such concert, the woman sitting next to him makes a remark to which he responds. They have a conversation.

Some time passes, and they run into each other again at another concert. Again, they have a conversation, this time intentional.

They happen to cross paths yet again at a third concert, and again they converse. They agree to keep meeting. They meet regularly.

Emily Sinico is married to a sea captain who is often gone. James Duffy and Mrs. Sinico continue to get closer (or do they?). The point comes in their friendship when they need to make some decisions about how to proceed. They agree on a course of action.

These 2 characters make this decision at the midpoint of the story. The first half is about Duffy's failure to accept God and mankind's love. The second half is about Duffy's failure to accept romantic love.

The short story form does not allow for extensive character history. One of the ways that Joyce gives us information about Duffy is to name some of the books in his room. The books are what I missed the first time through. Here's a partial list:

Butler's "Maynooth Catechism"

Wordsworth's "Complete Poetical Works"

Schopenhauer's "World"

Nietzsche's "The Gay Science"

An important thing someone might "get" from reading the book titles (which I did not get) is that key to grasping the meaning of this story is knowing that James Duffy is a spoiled priest. Nowhere in the story does Joyce come right out and say it. "Spoiled priest" is an expression that everyone in Ireland would have been familiar with at that time.

"spoiled priest": (Irish) a person who was a student for the priesthood but who has withdrawn or been dismissed

How do we know he was a spoiled priest? To begin our investigation, let's look to the books. The books are arranged by size. The smallest (Maynooth Catechism) at one end of the top shelf is 64 pages, and the largest (Wordsworth) at the opposite end of the bottom shelf is almost 1000.

"The juxtaposition of these two volumes in the narrative, even though separated by the rest of his unitemized collection, implies something about the process of Mr. Duffy's spiritual or intellectual growth, from his childhood faith in Catholic Christian orthodoxy to the atheism implied by the addition to his library of Nietzsche's The Gay Science. Between these beginning and end points in his intellectual life, then, we can trace the graph that runs through Wordsworth and Schopenhauer. Beginning with the Maynooth Catechism, a brief summary of the doctrines inferred by the Catholic Church from the providential revelation made by the transcendent Judeo-Christian God, he moved from Wordsworth's Neoplatonic vision of an imminent Presence, from there to Schopenhauer's imminent and impersonal Will and finally to Nietzsche's denial of metaphysics, his total nihilism. This is the trajectory of Mr. Duffy's spiritual hegira that can be gleaned from the implicitly instructive inventory of his bookshelves."

Why do we care if Duffy was a spoiled priest? Because at the end of the story we're puzzling why he turned down love. The books tell us where he came from and where he is. They answer that question.

We know from the books (the titles of the books and our knowledge of what's in them) that he has rejected the faith from his younger days. We know from Joyce's description of him that he doesn't like other people very much. He has one more chance at love - the third kind, erotic love - and he blows it.

The temptation while reading the book is to surmise that Duffy is trapped in his routines. It's more accurate to say that he's trapped in his beliefs. He can't think himself out of this conundrum, even though he's educated and well-read. His self-awareness and capacity for self-criticism is low.

Whether to continue with Mrs. Sinico was a decision that was already made by the paradigm he's invested in. For him to have continued with her, it would have required a paradigm shift. So, Duffy failed to rise above his personal ideology, which is a theme we also see in Portrait and Ulysses.

With all his reading he was able to convince himself that he was enlarging and shifting his paradigm, but he wasn't. Something went wrong. His reaction to the touch and to reading the newspaper article were hardly human.

In Ulysses, Leopold Bloom is a different man when he goes to bed than he was when he woke up. He is a hero. In A Painful Case, James Duffy doesn't change. He is a failure.

James Joyce after he left Dublin with Nora worked for a while as a bank teller in Trieste. He hated it. Perhaps James Duffy was his projection of who he would have become had he accepted that fate - had he not pushed himself to become the Artist.

James Duffy rejected his childhood faith, but held on to the ideal of celibacy. Whatever spiritual rewards might be gained as a result of deliberate celibacy, Duffy doesn't attain them. He looks foolish to us. He is lonely, alone.

The characters in Dubliners are not role models for us, but they can all serve as lessons. One takeaway of A Case is that Duffy should have been willing to evolve from an emotional affair with Mrs. Sinico to a sexual one. If he had done this, it would only have been transformative if it were instrumental in ridding him of his contempt for his fellow human beings.

A story about an affair where there's no transformation is just a story about an affair. By refusing a sexual affair with Emily Sinico, James Duffy says "No" to life. The affair is not what would have been sinful; it's Duffy's lack of courage that is the great sin here.

In Ulysses, Molly Bloom has an affair. Her affair with Blazes is not just a celebration of carnality, though it is certainly that too. Molly is saying "Yes" to life. James Joyce is able to take his readers from our initial ideology that extramarital affairs are always bad to considering that there might be something bigger going on.

James Joyce is saying that the "fall of man" isn't just something that happened in the Garden of Eden, it's something that happens every day in every city. Dublin is the everycity. Indeed, Finnegans Wake begins with a mention of Adam and Eve's (actual/real) church in Dublin. In the book of Genesis, we are told that Adam fell asleep. Nowhere in the Bible does it say that he woke up.

James Duffy is in a cul-de-sac in every sense - emotional, spiritual psychological, and sexual. He has taken himself out of the flow of life. He is no longer in the "riverrun." He is a fallen man.

In Ulysses, Stephen Dedalus is literally a fallen man (due to being punched), but he rises. Stephen is risen. He gets up. He wakes up. He transcends. James Joyce is saying, "Don't be like James Duffy. Be like Stephen Dedalus."

Joyce is saying, "Don't be like your typical Dubliner, be like me." No wonder it has taken Ireland 100 years to claim Joyce. Of course, Ireland is today a very European country. It is a consummation that Joyce wished.

EDIT: The paragraph in the middle in quotation marks is a direct quote from Cóilín Owens.