Albert Camus' story, The Stranger, was originally written in French, in the narrative style, in the first person. It is considered a "psychological self-examination," however Camus' work had a twist: the protagonist in the story does not provide a detailed description for the reader, leading him or her to the conclusions that writer has in mind, but rather presents the main character's "action and behavior" and lets the reader make his or her own judgments.
The primary reason for this is that Camus believed:
...psychology is action, not thinking about oneself.
The speaker leaves too many things up in the air because he has not explained everything in the narrative. Rather than "spoon-feeding" the reader with "commentary," Camus describes what the character is "thinking and perceiving," but the only influence the author provides to the reader is writing that reflects the attitude of Meursault—frustrating (to the reader) indifference, almost to the point that one wants to shake either Merusault or Camus or both. These gaps in the story by way of Merusault's behavior (or lack thereof), along with the half-informed opinions of those who testify at the trial, seal Meursault's fate.