Marital Incompatibility
At the center of "The Lamp at Noon" is the theme of marital incompatibility. The tension beneath Ellen and Paul's superficial communication quickly erupts into an argument over their incompatible visions of the future. Unable to counter Ellen's prediction that the soil will never become fertile, Paul relies on an ad hominem attack of Ellen's privileged upbringing. Paul leaves the dispute unresolved; only when alone does he entertain Ellen's opinion. Though Paul ultimately concludes that Ellen's concern is legitimate, he nonetheless cannot give up his defense of the land. The story ends with her admitting to Paul that he was right about the storm dying down; Paul meanwhile understands that Ellen had been right about everything else, but he is shocked into speechlessness and cannot tell her.
Environmental Degradation
"The Lamp at Noon" is set during the historical period known as the Dust Bowl, and another of the story's thematic preoccupations is the degraded prairie environment in which Paul and Ellen live. Harsh winds create a constant sonic disruption and kick up dust so thick that sunlight is blocked out. This inhospitable environment creeps into the house itself by coating everything in a layer of dust and threatening to dry out the character's throats. Though both Paul and Ellen recognize the desert-like conditions they live in, they disagree about the cause: Paul insists the dry years will end, while Ellen understands that the environment has been degraded by greedy farmers' poor soil management.
Economic Depression
Set during the Great Depression, the theme of economic depression underpins much of the conflict in "The Lamp at Noon." Paul and Ellen maintain their unprofitable homestead through government assistance and by taking on debt. Ellen would like Paul to give up on his delusion that the farm will become prosperous, but Paul knows the only work in town would be as a lowly shop assistant at Ellen's father's store.
Delusion
The theme of delusion arises several times in "The Lamp at Noon." Paul's imagined vision of future prosperity on his farm prevents him from seeing the stark and desolate reality that Ellen asks him to consider. It is not until the dust storm dies down that Paul's delusion is finally laid out before him: the land is a desert and he is a fool to have thought otherwise. Meanwhile, Ellen's delusion sends her running into the storm, as if she could escape harm by putting herself more directly in its way. By juxtaposing how the husband and wife both have the capacity equally for insight and delusion, Ross shows how both characters are in their own way right and in their own way wrong.
