"Tragic hero" is not an appropriate term to use in existential literature. It is a classic term, and many conditions must exist before it can be applied, the foremost being a character who "falls from a high place," which certainly can't be said of Meursalt. This novel (The Stranger) is, like all the work by Albert Camus, an example of fictionalizing the existential notion of "existence precedes essence." in other words, Camus is exploring the ramifications of seeing Man as designing himself by his actions, rather than following a divine design. Mersault's actions, unfathomable by so-called "moral laws," define him, If the reader comes at the story with no pre-designed notion about "right-and-wrong" At any rate, to call Mersault a "tragic" anything is to misunderstand Camus' motives for writing the book.