The Pit
The pit is consistently compared to a monstrous evil that envelops the miners.
Nature
Nature has a "belly swelled with a black and avenging army of men, germinating slowly in its furrows, growing upwards in readiness for harvests to come." It is the main arbiter of life and death in the novel.
Human Life
The workers are portrayed as highly expendable by the management and owners of the mines. They are reduced to transactional commodities.
Hunger
Physical, carnal hunger also speaks to larger moral, political, and economic hunger. There is an unsatiated, ravenous desire for a better life. This extends beyond comestibles and foodstuffs. The unbearable, harsh realities engage the higher sensibilities of the miners. Not only do they want to satisfy their base desires, but the awareness that Etienne brings about stimulates a critical, reflective faculty that makes them question non-carnal depravities such as equality, justice, and dignity.
Women
Some anthropologists, such as the French structuralist Claude Lévi-Strauss, have argued in favor of alliance theory: that is, the basic architecture of societies across the world is the exchange of women as property. However independent Catherine might be, she is still seen as something to be had. As such she is the chief cause of contention between Chaval and Etienne. Catherine is treated not simply as kin, but also as an item over which there is significant expenditure, expansion, and expression of ego. She is the embodiment - and also reveals the hypocrisy of - conflict between two miners who claim to want liberty, equality, and justice for a wretched populace.