Meursault is an apathetic man and doesn't even seems to be able to prevail or fail. Seemingly without any passion, he moves on without a care either way. When Marie, "...asked me if I loved her. I told her it didn’t mean anything but that I didn’t think so."
There are very few people or characters who don't care about love. There are very few people who experience little to no emotion at the death of their mother (" Maman died today. Or yesterday maybe, I don’t know. I got a telegram from the home: “Mother deceased. Funeral tomorrow. Faithfully yours.” That doesn’t mean anything. Maybe it was yesterday."). In the beginning of this novel Meursault almost seems like a failure of a person wasting away his life. As the reader we find ourselves frustrated with his character considering his lack of feeling and emotion as a problem rather than a simple characteristic.
But as the plot progresses, and especially by the end, we see how Meursault has truly succeeded in a way very few people have. His passion for the truth and to always tell the truth takes him to his very death. This passion, Camus argues, is one that isn't handled well by society and thus innocence leads to conviction.
The Stranger is a unique and unconventional answer to this question. His passion for the truth never falters which seems to be a recipe for success. Yet society turns it into a failure, death. From a more cynical view point, passion is not enough to yield success; the restrictions of society may inevitably cause some to fall.