This piece is characteristic of existentialism, the prevalent school of thought among the era's literature. It also presents Camus' concept of absurdism, as well as many examples of human choices. The dilemmas faced by Daru are often seen as representing the dilemmas faced by Camus regarding the Algerian crisis and there are many similarities between the character of Daru and his creator Camus. Both are French Algerians exiled by the choices they have made. The main themes of "The Guest" are of choice and accountability. Camus emphasizes, characteristically of existentialist philosophy, that there is always a choice, that the only choice unavailable is not to choose. Daru chooses how he will handle Balducci and whether he will turn in the prisoner; the prisoner chooses whether to go to jail or to freedom. More important, however, is the theme of accountability. The essence of Camus's philosophy is that everyone is "condemned" to an eventual, inevitable death, and accepting this allows for a certain freedom; the prisoner, having achieved self-awareness when Daru gave him the choice to flee or go to jail, realizes the futility of fleeing from the inevitable punishment and goes willingly to jail, thus revolting against the inevitable by making the decision of his own accord and holding himself accountable for the murder.
Daru's choice can also be seen as a "damned-if-you-do, damned-if-you-don't" situation. Daru makes his decision based on what he believes to be the right thing to do. The fact that he will be punished for doing the right thing does not make it any less right. The important point is that people must do what they feel is right, without worrying about how others feel, or about possible rewards or punishments.
Yet another theme can be extracted from this short story, however: complete neutrality is unattainable. This is evidenced by Daru's attempt to avoid making a decision; in the end, the Arab makes the decision for him, and he loses his neutrality.