Near the beginning of Flannery O'Connor's comic story "Good Country People," she narrates:
And she said such strange things! To her own mother she had said without warning, without excuse, standing up in the middle of a meal with her face purple and her mouth half full Woman! Do you ever look inside? Do you ever look inside and see what you are not? God! she had cried sinking down again and staring at her plate, Malebranche was right: we are not our own light. We are not our own light! Mrs. Hopewell had no idea to this day what brought that on. She had only made the remark, hoping Joy would take it in, that a smile never hurt anyone.
Malebranche was a 17th Century French philosopher who said, in Dialogues in Metaphysics, that:
'I am not my own light to myself'
and that, according to Enotes:
1) If we see all things in God in the sense that He puts the ideas into our minds we can have no direct knowledge of the external world. We can appeal to clear and distinct ideas as a criterion for the veridicality of judgements about physical things, but it is God who is ultimately responsible for our ideas.
(2) If all things are under the direct control of God — subject to His will, what of human freedom? Malebranche's view that we have freedom to choose but only in relation to finite goods is not convincing, denying as it does the possibility of resistance of movement towards God as the universal good.
So, Joy/Hulga is a Malebranchean: she's a kind of Christian nihilist that says we have no real freedom, that we cannot see God's handiwork in nature, that there is no revelation of God in the natural world.
Miss O'Connor says that man does not have unadulterated free will. She says he has "many wills conflicted" inside himself: his will, God's will, other's wills. Miss O'Connor characterizes a split in Joy/Hulga that makes room for a duality. I see it as a split between material individuality and spiritual personality: Hulga, like Christ, is both carnal and spirtual. According to personalism, the spiritual aspect of personality is a creative unity, free and independent, and it animates the flesh. Although we can distinguish each from the other, Malebranchean says we cannot separate individuality from personality. They combine, like body and soul, to form a unified human being: "the material pole, which is but the 'shadow of personality,' tends to draw things to itself. The spiritual pole, contrariwise, which concerns true personality, is what Aquinas has in mind when he speaks of a source of generosity and bountifulness." Thus, Miss O'Connor achieves both duality and unity.
All this to say that Miss O'Connor's art creates a dialgogic between artist and reader and between hero and God whereby man--through suffering, sin, and blasphemy--casts off a part of himself, his material individuality, which interrupts his communication with God and others.