The bell jar
symbolizes mental illness and gives the novel its title. It is Esther
’s own metaphor for describing what she feels like while suffering her nervous breakdown: no matter what she is doing or where she is, she sits alienated “under the same glass bell jar, stewing in my own sour air.” Though she can see through the transparent glass to the world beyond, the glass jar distorts the image of that world, leaving the suffering viewer with a warped understanding of reality. After undergoing electric shock therapy and analysis at the mental asylum, Esther feels the bell jar lifted. However, even as she welcomes health, she fears a future re-descent of the bell jar and wonders whether other bell jars also imprison the seemingly sane people around her.