There are several themes running through the novel and many overlap, but the most obvious are the following:
Lady Runcie-Campbell’s conflict between trying to appear Christian and upholding her aristocratic ideals recurs throughout the novel. The theme is also examined through Calum’s childlike innocence contrasting with Duror’s ‘snakes of damnation’ evil mentality and cruel actions.
Calum is extremely close to nature but does not feel close to the human world. He is at home in the natural world:
…it was a good tree…with rests among its topmost branches as comfortable as chairs.
Duror is jealous of Calum’s affinity with nature.
Lady Runcie-Campbell believes she is superior to the lower classes. Duror enjoys the small luxuries he is given because of his higher-status job as a gamekeeper, but Neil hates the class structure:
We’re human beings just like them.
This carries through to the end.
Religious symbolism is suggested in the death of Calum, whose innocence and sacrifice can be compared to Christ’s.
Neil also makes sacrifices for his younger brother Calum. This is evident throughout the novel. He gives up any chance of romance and settling down to have a family in order to look after his disabled brother.
The human sacrifice of those who are losing their lives in the war is reiterated to highlight the cost of liberation.
The theme of war is recurrent throughout and is highlighted through the impact it has made on the estate and on every character and their actions. The background of World War Two suggests that evil is to be found in humans everywhere, showing it is not simply confined to the woods on the estate.
The war means that Lady Runcie-Campbell is left to run the estate, with Duror's poor advice. Her husband, had he not been away at war, would perhaps have made more sensible decisions. The war allows Neil to believe in a future where there is social justice and equality.
Duror seems to support the Nazis’ regime:
the Germans were putting idiots and cripples to death in gas chambers.
Having been rejected from the army, Duror is still part of the Home Guard, so despite appearing to ‘fight’ against Hitler, he shares some Nazi ideals.