In "Good Country People," why is it significant that Mrs. Hopewell's daughter has two names?
Flannery O'Connor's writing is full of meaning and symbolism that is "hidden in plain sight" as it is woven into a seamless narrative. One of O'Connor's favorite character types is the intellectual or the pseudo-intellectual who believes that she can control her life and control others. Such a character is Joy/Ulga. In her nihilism, she rejects the name of Joy as frivolous, and takes the unappealing name of Ulga because she has lost the joy of spiritualism and replaced it with vain intellectualism. She also chooses the name Ulga as a rejection of her mother and the platitudes she recites daily.
Believing herself superior to the "good country people" pointed out by her mother, Mrs. Hopewell, and the woman who works for her, Mrs. Freeman, Ulga sets out to prove her superiority by controlling Manley Pointer (pointed out as "good country people"), an itinerant Bible salesman. One evening she plans a meeting with him in the barn, and they climb to the loft where Manley with eyes "like two steel spikes" steals her leg after convincing her to remove it. Without her leg, Ulga feels vulnerable and hopeless because she lacks any faith. She shouts at Manley,
"You're a fine Christian! You're just like them all--say one thing and do another."
He replies to her, "...you ain't so smart. I been believing in nothing ever since I was born!"
With his violent act of stealing her leg, Manley provides Ulga the chance to accept grace and spirituality now and benefit from this humiliation; then she can truly become Joy.
The two names represent separate identities residing in the one person. Joy is no longer joyful, having had her life ruined by an accident that caused permanent disability. As far as she's concerned, her life is as good as over. In her mind, "Joy" is as much a cruel, vicious lie as "Hopewell." There is no joy; there is no hope; so Joy has to go.
It's fair to say that Hulga's not the most elegant of names. But it certainly seems to suit Joy in her present condition of hatred and bitterness towards the world. There is a sense, however, in which Joy has made a conscious choice to act towards others the way she does. She had no control over what happened to her, but she does have the ability to choose how to respond. And she's made that choice: a choice of a whole new persona, one that reflects who and what she thinks she now is. For good or ill, Joy/Hulga has changed her stance towards the world. Changing her name simply sets the seal on an existential decision she made long ago in response to a chronic disability.
Mrs. Hopewell's daughter was given the name Joy, but it doesn't seem to fit her. At age 10, she lost a leg in a hunting accident, and, when she was 21, she legally changed her name to Hulga. Mrs. Hopewell refuses to call her daughter Hulga, as the name makes Mrs. Hopewell think "of the broad blank hull of a battleship." Her daughter replies in a mechanical fashion to her mother, who still calls her "Joy."
These two names symbolize the hopes that Mrs. Hopewell (whose name is symbolic) harbors for Joy to lead a good life and the hatred and bitterness that Joy/Hulga feels about the way in which her life has turned out. Mrs. Hopewell's daughter has decided to revel in the grotesqueness of her leg, and she even stomps around on it. Calling herself Hulga accentuates this grotesqueness, and it allows herself to express herself by choosing the ugliest name she can possibly dream up. In using this name, she is rejecting her mother's wishes for her and delighting in this rejection.