Shirley Jackson's 'protagonist' in her short story The Possibility of Evil almost certainly does not realize that she has done anything wrong. On the contrary, Adela Strangeworth is, by all indications, a psychopath with no sense of social propriety and no grasp of conventional notions of right and wrong. Jackson's story develops gradually but consistently towards the revelation that her main character is the very evil she (Miss Strangeworth) ostensibly rejects. Her very name -- Strangeworth -- suggests that something about this character is a little bit 'off.' Initially, Miss Strangeworth's main idiosyncrasy appears to be a propensity for judging her neighbors and fellow townsfolk too harshly despite a marked concern for their well-being. Her observations are focused upon the shortcomings of others, as when she considers the failure of the town librarian, Miss Chandler, to brush her hair that morning. As Jackson's narrator notes, "Miss Strangeworth hated sloppiness."

Soon enough, we are presented with the true nature of this character. Returning to her home, Miss Strangeworth prepares to write letters, and in so doing the reader is exposed to another indication that she is less munificent an individual than initially thought:

"Although Miss Strangworth’s desk held trimmed quill pen… and a goldfrosted fountain pen,... Miss Strangeworth always used a dull stub of pencil when she wrote her letters, and she printed them in a childish block print."

The reader is by this point apprised of the somewhat difficult nature of this character, but will only now be introduced to the evil that Miss Strangeworth represents. As she writes her anonymous letters, clearly intended to hurt feelings and create rifts among her fellow citizens, the full extent of her cruelty is revealed. As she continues this pernicious activity, the narrator notes that "Miss Strangeworth liked writing her letters," and that she truly believed that this activity was a justifiable response to the evil she viewed in others:

"She had been writing her letters – sometimes two or three a day, sometimes no more than one in a month – for the past year. She never got any answers, of course, because she never signed her name…. The town where she lived had to be kept clean and sweet, but people everywhere were lustful and evil and degraded, and needed to be watched; the world was so large, and there was only one Strangeworth left in it."

The best evidence that Miss Strangeworth is cognizant of the perniciousness of her conduct is the method she employs in concealing her activities. As Jackson's narration describes this process:

"Although Miss Strangeworth had never given the matter any particular thought, she had always made a point of mailing her letters very secretly; it would, of course, not have been wise to let anyone see her mail them. Consequently, she timed her walk so she could reach the post office just as darkness was starting to dim the outlines of the trees and the shapes of peoples’ faces, although no one could ever mistake Miss Strangeworth, with her dainty walk and her rustling skirts."

This passage is an important indication that Miss Strangeworth is fully aware of the nature of her conduct, which suggests she recognizes the distinction between right and wrong. It is, however, that very distinction that poses the problem. The ability to distinguish between right and wrong is a true indicator of sanity -- at least in the practice of criminal law. This does not, though, lead one to conclude that she views her activities as morally wrong. She justifies her conduct by the acknowledgment that "wickedness was never easily banished," and, consequently, the defeat of evil required extreme measures -- measures that only she was prepared to take. It is in this light that one reads the story's final passage, in which she reads the anonymous note that she receives informing her that her prized rose garden has been destroyed: "She began to cry silently for the wickedness of the world when she red the words: Look out at what used to be your roses." It is this reaction to the destruction of that which she held most dear that illuminates the extent to which she has continued to justify her conduct on the basis of moral righteousness. She does not believe that she has done anything wrong. To her, her failure is in her inability to preserve her anonymity as the purveyor of painful information. To Miss Strangeworth, she only did what needed to be done.

What are Miss Strangeworth's motivations in "The Possibility of Evil" by Shirley Jackson?

Miss Strangeworth is a complex character. She believes it is her civic duty as the town's oldest resident and descendant of the town's founders to act as a sort of guardian of public morality. The truth seems to be that her real motivations are envy and jealousy. It is significant that all the people whose lives she has affected with her anonymous letters were made to feel threatened about their relationship with someone close to them. For example, both Don and Helen Crane are worried about the development of their infant daughter, and Miss Strangeworth intensifies their worries with a number of letters. Her latest one reads:

Didn’t you ever see an idiot child before? Some people just shouldn’t have children, should they?

Miss Strangeworth has never had a baby. She has never been married. She may never have had a boyfriend, or even a date. She is really a pathetic creature, a lonely old woman pretending to be an important member of the community. The recipients of the three letters she writes in this story all have someone they care about. For example, Mrs. Harper, one of Miss Strangeworth's contemporaries, has a husband. The latest poison-pen letter addressed to her reads:

Have you found out yet what they were all laughing about after you left the bridge club on Thursday? Or is the wife really the last one to know?

Old Mrs. Foster has a nephew she cares about, and who presumably cares about her. The letter she receives reads:

You never know about doctors. Remember they’re only human and need money like the rest of us. Suppose the knife slipped accidentally. Would Doctor Burns get his fee and a little extra from that nephew of yours?

The adverse effects of Miss Strangeworth's letters can be seen in other characters who received them in the past. Most notable are young Dave Harris and Linda Stewart, the lovers whose relationship has nearly been destroyed by a letter Miss Strangeworth sent to Linda's parents suggesting that the teenagers were getting inappropriately involved. The kindly little spinster is gratified when she happens to overhear them talking.

“I can’t tell you, Dave,” Linda was saying – so she was talking to the Harris boy, as Miss Strangeworth had supposed – “I just can’t. It’s just nasty.”

In every instance it can be seen that a relationship is imperilled by one of this unhappy woman's poison-pen letters. Dave and Linda might have gotten married. Don and Helen Crane may never dare to have another baby. Old Mrs. Foster may never feel the same about her nephew again. Miss Strangeworth had only taken up the hobby of writing her letters in the past year, and already she can see visible evidence of their effects on townspeople--although she does not understand that they could have any connection with her letters. Or at least she cannot permit herself to understand that her letters are creating chaos in a once-peaceful little town.

Many people seemed disturbed recently, Miss Strangeworth thought.

She has nothing to do with her time. She buys only tiny amounts of groceries each time she visits Mr. Lewis's store, so she has to keep going back nearly every day. Mr. Lewis has been looking worried lately. 

Mr. Lewis would never have imagined for a minute that his grandson might be lifting petty cash from the store register if he had not had one of Miss Strangeworth’s letters.

Evidently, Miss Strangeworth tells herself that her motive for interfering in people's lives is to uphold civic morality, but her real motive appears to be to prevent others from enjoying the human affections she never experienced herself.