Plath’s central intention in The Bell Jar seems to be to depict the harrowing reality of a worsening mental condition when the person is beginning to lose contact with the world around her. One impressive technique is the distorted descriptions of everyday life. For example, her new and expensive clothes are hanging “limp as fish” in her closest; German words are “dense, black, barbed-wire letters”; and to describe the clothes of Hilda, a fellow guest-editor, “fashion blurbs, silver and full of nothing, set up their fishy bubbles in my brain.” As Esther returns home after her month in New York City, the phrases indicating distortions give way to distorted descriptions of entire landscapes and incidents.

The theme of appearance versus reality is important in The Bell Jar in several ways. Externally, Esther Greenwood seems to enjoy a very successful life: She is a scholarship recipient at a prestigious school, a published poet, and the winner of a month in New York as the guest-editor of a magazine. Internally, she questions her identity, believes that she cannot continue to be successful, finds herself socially awkward, and feels herself to be sexually unfulfilled. Existentially, she challenges the meaning of the successes that she has attained.

The ironic tone of the narrator is one of the principal literary devices used to create the bifurcated vision of a highly intelligent young writer who sees both the conventional façade and the reality behind it. One example of such duplicity is the luncheon for the guest-editors given by Lady Day magazine. Although the kitchens gleam with spotless stainless steel counters and ranges, the crab meat gives them food poisoning. On another occasion, Esther observes Dr. Gordon, her first psychiatrist, carefully creating a physical and psychic space between himself and his patients. The problem is that this ironic perception creates the divisiveness within Esther. She wishes she could be like fellow guest-editors Betsy and Doreen, who commit themselves totally to the view of life in which they believe.

Some female characters are used as alter egos. Of the young women who are also guest-editors during the summer in New York, Esther believes that two of them represent two divisive parts of herself. Betsy, from Kansas, is like the part of Esther that has conformed almost obsessively with the norms of society. Doreen, on the other hand, is Esther’s shadow side: the urges she has not expressed but would like to. Esther alternates in loyalty from one to the other but feels torn between the two.

Esther’s treatment at the sanatorium is paralleled with that of another student from her college, Joan Gilling. Esther has been unable to find a man who can measure up to her expectations, but she is still shocked to discover that Joan is a lesbian. Just when Joan seems to be recovering and is therefore allowed more periods of time outside the sanatorium, she commits suicide. Attending Joan’s funeral, instead of being drawn to suicide, Esther finds herself opting for life.

Since Plath was a poet, it is not surprising that she used many thematic images in The Bell Jar. Several images continue the theme of depression. The fetus of a dead baby in a jar suggests the unfulfilled life; yet Esther, when she is skiing down a slope for the first time, wants to return to the womb, apparently as a refuge to avoid decision-making. Later, she recalls a dream of a fig tree containing figs that represent all the choices life holds out to her; the only condition, however, is that she must make one choice. Since Esther wants all of them, she is unable to choose, and all the ripe figs turn black and die.

The major symbol is expressed in the title. As Esther feels herself retreating from life, she compares her isolation to being under a glass bell jar: She is unable to make contact with the world around her that she can see through the glass. Although the electroconvulsive therapy that she is given has lifted the bell jar, she sees it as temporarily suspended, ready to drop down and enclose her again.