This indifference is evident throughout the novel and one level may be interpreted as cold-heartedness, indifference to the world and even immoral. It may also be viewed as a trope for examining the insignificance of man (and woman) in the light of absurdism. Meursault comes to represent an everyman of sorts, whose apparently honest and recognizable thoughts are both anathema to humanity and realistic in that ultimately we will die and the world will keep turning.
This understanding of indifference is balanced, however, by the murder of an Arab man in French-run Algeria. Meursault is not an Arab and is, therefore, part of the elite in this country. It should be remembered that he never fully acknowledges any regret for his actions and he may also be read as a cipher for the French colonial power’s indifference to the suffering of the native-born Algerians.
The only explanation that Meursault can offer for the murder he commits is that he is affected by the conditions around him. The heat and light of the sun are strong thematic concerns as they are referred to incessantly, but they also act as a metaphor for his status as an outsider.
As a Frenchman in Algeria, the heat of the sun finds him out as the colonial intruder. The sun may be seen to symbolize how this is a foreign country and that he is the alien here despite the rule of the French at the time of writing.