How is Pitty Sing (the cat) instrumental to the whole plot of "A Good Man Is Hard To Find"?
Pitty Sing's mishap provides the last comic note in the story before events turn dark and macabre. The Grandmother, not a respected person in the family, knows her son, Bailey, won't allow a cat to stay with them in the motel room. Therefore, as they head out on vacation, she hides Pitty Sing (which sounds like "pity sings") in a basket under her big black valise. In what will turn out to be a highly ironic train of thought, the Grandmother rationalizes:
She didn’t intend for the cat to be left alone in the house for three days because he would miss her too much and she was afraid he might brush against one of her gas burners and accidentally asphyxiate himself.
We don't hear about the cat again until The Grandmother manipulates Bailey into turning down a deserted dirt road in search of an old plantation. She become deeply embarrassed as she suddenly remembers the plantation is in Tennessee, not Georgia, the state they happen to be in. Because of her embarrassment, her "feet jumped up," upsetting the valise and freeing Pitty Sing to leap from the basket onto Bailey's shoulder. He is so startled he flips the car over into a ditch. We learn that:
Bailey remained in the driver’s seat with the cat gray-striped with a broad white face and an orange nose clinging to his neck like a caterpillar.
Once the car flips, that's the end for the family, because The Grandmother foolishly identifies The Misfit.
Had the Grandmother not been so worried, ironically, about her cat asphyxiating himself, she and her entire family might not have been murdered.
In O'Connor's short story, " A Good Man Is Hard to Find," Pitty Sing, the cat, is instrumental to the plot and the grandmother's characterization. First of all, the grandmother hides the cat in the car even though her son, Bailey, does not want the cat on the trip. The grandmother shows little respect for her son's wishes, which illustrates deception and discord within the family, as well as the grandmother's obstinate nature. This foreshadows the accident that occurs later in the story.
The cat is the root cause of the accident that brings the doomed family in contact with the Misfit. When the grandmother insists on finding the plantation she thought she remembered along the dirt road, the luggage knocks into Pitty Sing's basket, causing the cat to spring out and attach itself to Bailey's shoulder. Bailey loses control of the car, and it turns over. That is the beginning of the end for the family.
Interestingly enough, as the family is shot one by one, ironically, the cat befriends their killers. The Misfit picked up "the cat that was rubbing itself against his leg" as he orders the grandmother to be shot. The cat is the only survivor.
The cat in O'Connor's "A Good Man is Hard to Find" causes the accident that leaves the family stranded in the vicinity of The Misfit and his partners in crime.
In this O'Connor story, the grandmother must come into contact with The Misfit. The spiritually fallen woman must interact with the twisted, grotesque force that shows her the error of her ways, so to speak. The cat enables O'Connor to steer the grandmother toward the meeting. This leads to the woman understanding, perhaps and at least in part, the truth of her beliefs and behaviors. It also allows The Misfit to reveal the truth that he speaks of when he declares that she would have been a good woman if someone had held a shotgun to her head everyday of her life.
O'Connor believed that this was the only means of salvation for spiritually hardened or lackadaisical Christians.
Incidentally, the cat's presence in the car reveals characterization of the grandmother as well as adding to the plot: it provides still another example of her disrespect for others and her haughty nature.