Female identity
When speaking to the female characters in Trifles, Henderson and the other men make a key mistake in their assumption that the women derive their identity solely from their relationship to men, the dominant gender. For example, Henderson tells Mrs. Peters that because she is married to the sheriff, she is married to the law and therefore is a reliable follower of the law. Mrs. Peters' response is "Not--just that way," suggesting that over the course of the play, she has rediscovered a different aspect of her identity that ties more closely to her experience as a woman than to her marriage to Henry Peters. As Mrs. Hale concludes, women "all go through the same things--it's all just a different kind of the same thing." For Mrs. Hale, Minnie Wright's murder of her husband is the ultimate rejection of her husband's imposed identity in favor of the memory of the person Minnie Foster used to be.
Law, duty, and justice
Because Trifles is a murder mystery in which the sleuths decide to hide the evidence of the crime and thus end by aiding the murderer, the play leaves open the question of the meaning of duty and justice. For men such as George Henderson and Henry Peters, the concept of law and order is intricately linked with duty and justice, and at first, Mrs. Peters ascribes to the same interpretation. Consequently, whenever Mrs. Hale criticizes the men for their heavy-handed methods of investigation, Mrs. Peters, who is also the sheriff's wife, apologizes for the men because she sees them as performing their duty. However, Mrs. Hale convinces her that true justice would involve punishing everyone who had neglected and isolated Minnie Wright, and that Mrs. Wright was perhaps justified in her retaliation against her husband. Appropriately, the name of the short story adapted from Trifles is "A Jury of Her Peers," indicating that Mrs. Hale and Mrs. Peters have served as an impromptu jury and have chosen to dismiss the charges in the name of justice and their duty as women.
Patriarchal dominance
In Trifles, the men believe that they grant female identity by virtue of the women's relation to men rather than through their inherent qualities as females. Except for the absent Minnie Wright, the women have no first name and take their husband's last names, despite being the protagonists of the story instead of the named male characters. This institutionalized male superiority is so pervasive that the men feel comfortable in disparaging Mrs. Peters and Mrs. Hale's interest in "trifles," with the clear implication that the women are too flighty and small-minded to worry about important issues such as the investigation at hand. In addition, when the men observe the troublesome state of the kitchen, they immediately conclude that the woman must be at fault in her homemaking abilities because they all know John Wright as a good, dutiful man and in consequence form a unified front protecting John Wright's reputation. Because of this male solidarity, Mrs. Peters and Mrs. Hale can only aid Mrs. Wright if they ally with their own gender.
Revenge
After Mrs. Peters and Mrs. Hale discover the dead canary in Mrs. Wright's sewing basket, they realize that her murder of her husband did not result solely from her unhappiness in her marriage but from an enforced return to solitude by the killing of her pet bird. Mrs. Wright killed her spouse because she could think of no more fitting revenge than to inflict damage in kind to the perpetrator. This realization catalyzes Mrs. Peters' sense of empathy, as she recalls having had similar feelings many years ago when a boy killed her kitten. For these women, the pain that results from the death of a loved one is so great that it deserves any punishment necessary. Nevertheless, the play leaves open the question of whether Mrs. Wright will still be convicted without the evidence, and similarly we must decide for ourselves if revenge is a sufficient motive for murder.
Domesticity
When Henderson observes the Wright kitchen, he concludes that Mrs. Wright must not have "the homemaking instinct," which Mrs. Hale interprets as an attack on Mrs. Wright's worth. Her countering of his statement with the suggestion that Mr. Wright did not have the homemaking instinct establishes two alternate interpretations of the meaning of domesticity. According to one definition, domesticity is the ability to keep a home in the purely physical sense, with a clean kitchen and well-sewn quilts. In her final moments prior to the murder of her husband, Minnie Wright rebels against these standards of domestic prowess because in her eyes, her husband has failed to meet the second definition of domesticity, which depends upon one's ability to make a home warm and comforting emotionally. Henderson fails to comprehend that the latter form of domesticity is as important as the first type, as shown by his disregard for signs of a troubled marital life in the Wright household.
Loneliness
While the need for revenge is the immediate impetus for Minnie Wright's strangling of her husband John, her isolation is the ultimate causes of her unhappiness in their marriage. As Mrs. Peters and Mrs. Hale note, John Wright was a hard man and did not provide the companionship needed, while Mrs. Hale blames herself for never having visited to offer Mrs. Wright a respite from her loneliness. Both women suspect that the canary had been a substitute for Mrs. Wright's lack of children and other friends, and Mrs. Peters' account of her solitude while homesteading in Dakota suggests that loneliness is an important element of the female and human condition. Mrs. Hale realizes that woman have all experienced loneliness in part because they do not realize their commonality and thus have not learned to unify and support each other. In the end, loneliness connects the women and brings them closer to each other.
Empathy and protection
At the beginning of Trifles, Mrs. Wright is an unknown quantity whose behavior in Lewis Hale's account is puzzling and bizarre. By the conclusion of the play, however, the substance of her personality and life has been revealed through Mrs. Hale's memories and through a few small details contained on the first floor of her house, and her character becomes the subject of sympathy and finally of empathy. Because Mrs. Peters and Mrs. Hale come to realize the similarities between the murderer and themselves, they decide that Minnie Wright is worthy of their protection, which has several meanings for the women. Most obviously, they unify with her against the law, as represented by the men of the play, but they also protect her by not telling her the truth about her ruined preserves. In addition, Mrs. Hale regrets not having protected Minnie from isolation and solitude, and she resolves to atone for her inability to protect Minnie earlier by helping her now.
