Plath was so concerned about the closeness of her novel to her life that she published it under a pseudonym, Victoria Lucas (just as in the novel Esther plans to publish a novel of her life under a different name). It only appeared under Plath's real name in 1966, three years after she committed suicide.
The story relates a year in the life of Esther Greenwood, who seems to have a rosy future in front of her. Having won a competition to guest edit a magazine, she travels to New York. But, she worries about the fact that she is still a virgin; her encounters with men in New York go badly awry. Esther's time in New York heralds the start of a slow mental breakdown; she slowly loses interest in all the hopes and dreams.
Dropping out of college and staying listlessly at home, her parents decide that something is wrong and take her to a psychiatrist, who refers her to a unit that specialises in shock therapy. Esther's condition spirals even further downwards due to this inhumane treatment, and she finally decides to commit suicide. Her attempt misfires however, and a rich older lady whose support Esther had gained through her writing agrees to pay for treatment in a center that does not believe in shock therapy as a method for treating the ill.
Esther slowly starts her road to recovery, but a friend she has made at the hospital isn't so lucky. Joan--a gay woman who had, unbeknownst to Esther, fallen in love with her--appeared to be cured of her illness, but she commits suicide when she leaves the hospital. Esther decides to take control of her life and is once more determined to go to college. However, she knows that the dangerous illness that put her life at risk could strike again at any time.
Perhaps the single greatest achievement of Plath's novel is its outright commitment to truthfulness. Despite the fact that the novel has all the power and control of Plath's best poetry, it does not skew or transform her experiences in order to make her illness more or less dramatic. The Bell Jar takes the reader inside the experience of madness like very few books before or since.
When Esther considers suicide, she looks into the mirror and manages to see herself as a completely separate person--from herself and from the world. Being trapped inside the "bell jar"--the symbol Plath uses to explain this strange feeling of alienation--is precisely what stops her from functioning on a human level (at one point she even refuses to wash herself). But, the "bell jar" also steals away her happiness.
Plath is very careful not to see her illness as the manifestation of outside events. If anything, her dissatisfaction with her life is a manifestation of her illness. Equally, the end of the novel does not pose any easy answers. Esther understands that she is not cured; in fact, she realizes that she might never be cured, and that she must always be vigilant against the danger that lies within her own mind.
This danger made itself felt to the books author, Sylvia Plath, not very long after The Bell Jar was published. Plath committed suicide in her home in England.
The Bell Jar does not quite reach the poetic heights of Sylvia Plath's poetry (particularly her supreme collection Ariel, in which she investigates similar themes to those that can be found in The Bell Jar), but the novel should be judged on its own merits. Plath managed to instill a sense of powerful truthfulness and brevity of expression in the novel--which anchors it to real life.
When she chooses literary images to express her themes she cements these images in everyday life. For example, the book opens with an image of the Rosenbergs who were executed by electrocution, an image that is repeated when Esther receives electro-shock treatment. Really, The Bell Jar is stunning portrayal of a particular time in a person's life and a brave attempt by Sylvia Plath to face her own demons. The novel will be read for generations to come.