In the opening story "The Sisters" from The Dubliners, you might find the answer to the question in the italicized words: gnomon, paralysis, and simony. These form the heart of what plagues the characters in these short stories.
Paralysis is the most pervasive cause of the individual characters' tragedies. The characters are trapped by their poverty, routine, religion or sense of duty, or the past. In "Araby," the narrator longs to escape the drudgery of his surroundings and sees Mangan's sister as a key to that escape. Going to the bazaar to find her a gift gives him a sense of purpose, a mission that blinds him to the drabness of his surroundings. Bitter and disillusioned at the end of the story, the narrator finds that there is no Araby in Dublin. Eveline is another character whose tragedy is her inability to escape; she is paralyzed by her sense of duty, her obligations to her family, her fear of the unknown, and at the end of the story she cannot go to Buenos Aires with Frank and becomes a "helpless creature."
But the other two words are also keys to the tragedies that face the characters in these stories. Religious corruption or blindly following religious routines is the heart of "The Sisters." Many stories have the symbol of a dead priest or empty chalice to show the inability of the church to provide true inspiration to its members.
The gnomon is a parallelogram with a smaller parallelogram taken out. The idea of a missing piece or obscured truth is prominent in many of the stories, but most specifically in "The Dead," when Gabriel realizes that he did not know his wife at all (a missing piece) and that he cannot compete with a ghost from his wife's past.