Though his appearance in The Stranger is confined to just two chapters, the timing of the appearances of Thomas Pérez are vital to understanding how the society that judges Meursault perceives him.

Thomas Pérez had been "inseparable" with Madame Meursault and he takes her death "very hard." In fact, the doctor refuses to allow him to attend the vigil, presumably because he is overwrought. Pérez's emotional attachment to Madame Meursault stands in stark contrast to the indifference and even annoyance of Meursault at the death of his mother and the cultural and societal expectations that he attend her vigil and funeral and demonstrate his grief for those in attendance. His inability to produce those emotions attracts attention in a way that will come back to haunt him when he is on trial for the murder of the Arab.

Pérez is limping and unwell, yet he insists on following the funeral procession in the extreme heat because of his devotion to Madame Meursault.

Later, at Meursault's trial, Pérez does not implicate Meursault, but his testimony is manipulated by the prosecutor. He says he was so caught up in his own grief that he did not see whether Meursault was crying. He also did not see whether Meursault was not crying. In any case, the message is that Pérez demonstrated the appropriate societal response at Madame Meursault's funeral while her son did not.

Thomas Pérez is a foil for Meursault. He symbolizes a societal norm regarding the observance of death, while Monsieur Meursault is judged as outside the norm.

Thomas Perez is a foil character. A foil character is used to highlight another character by contrast. Perez is deeply moved by Meursault's mother's death, but Meursault is indifferent and even annoyed at times. Perez's compassion makes Meursault's lack of emotion seem more dramatic by comparison. Perez is symbolic of the socially acceptable way to grieve. By contrast, Meursault's behavior seems unacceptable. Even though he implies that he and his mother were not close, his lack of caring is odd, and in comparison with Perez, it seems absurdly indifferent.

This is a good example of Absurdity in literature. Readers might find Meursault's behavior and thoughts to be absurd because he seems socially indifferent. But as the novel progresses, we learn that Meursault does not care for social rules and roles. So, for Meursault, regardless of his and Perez's respective relationships with his mother, the way Perez grieves seems absurd. In fact, Meursault ignores the human element and pays more attention to Perez's appearance and clothing. He notes the physical movement of Perez's tears and ignores what the tears really symbolize.

Some other memories of the funeral have stuck in my mind. The old boy's face, for instance, when he caught up with us for the last time, just outside the village. His eyes were streaming with tears, of exhaustion or distress, or both together. But because of the wrinkles they couldn't flow down.

In this respect, it seems that Perez cares and Meursault does not. Meursault seems absurd to Perez, and Perez seems absurd to Meursault. In fact, Meursault seems absurd to almost anyone. So, why does Meursault act the way he does? Meursault does not follow many social rules. He is an existentialist in this way: he creates his own persona, ignoring social norms. This makes him come across as rebellious but also cold-hearted. The comparison between the two men highlights their differences. Perez is compassionate, socially acceptable, and humanistic. Meursault is removed, socially abnormal, and inscrutable. Perhaps a question Camus wants to raise is whether Meursault's social rebellion is redeeming or interesting in some way, if it is deplorable, or if it is some combination of these things.