The Stranger is a tent-pole of existentialism, a philosophy that stresses the importance of humanity in the face of God's supposed absence. Readers will note that the central character, Meursault, portrays this lonely way of thinking by providing a strange and disquieting narration of the events unfolding before him with startling dispassion. Students will be wary of Meursault's atypical behavior; the novel's opening lines, "Mama died today. Or yesterday maybe, I don't know," perfectly illustrate the backwards, disjointed manner of thinking Meursault possesses.

Scholars and literary critics have debated at length whether Meursault should be considered a hero or a villain for his actions and, more importantly, his reaction to the world around him. Indeed, this argument mirrors the trial towards the second half of the novel, during which a faceless jury and an irate judge accuse Meursault not of murder, but of being an outsider to humanity and for not expressing sorrow or any emotion at all. Students will likely contribute a lot of opinions on this subject: On the one hand, Meursault is responsible for a terrible crime and is very likely a sociopath; but on the other, his prosecutors' inability to try to understand him leads Meursault to joyfully accept death and express contempt for his fellow man.

From his passive refusal to obey common customs to his relatively minimalistic manner of speaking, Meursault perfectly demonstrates the isolation present at the center of our society. The Stranger's central theme deals with the oppressive responsibility of "fitting in," and how a person's inability to conform can lead to his death. Teachers can engage students in multiple discussions about how real this phenomenon actually is and whether it was the author's intent to bring attention to it. Students would be tasked to find ample evidence to support their claims. For example, the sun is a common motif, which could be said to represent the burden of life without justice or absolute truth. The stars and night sky, by contrast, are used to convey the emptiness of space, the indifference Meursault feels toward every aspect of his life, and the irony that one of the only times he expresses any emotion whatsoever is when faced with the certainty of death.