Huh?

So I had just finished chapter six of The Stranger, and before I could even close the book, I felt a looming mass of confusion beating around in my mind jumping and stomping around threatening to burst. Why did Meursault shoot the guy? Why did he both walking towards the guy? Could there possibly be a logical explanation behind his actions? The way I read it, it seemed as if he was suffering from heat hallucination. Sure the Arab guy had pulled out a threatening weapon, but he wouldn't have if Meursault had not walked towards him in the first place. Who is to blame? And why must there be any blame? I mean yes someone died, but for what purpose?

Ironically, just before Meursault decides to take the fateful walk on the beach, a thought flashes through his mind: "to stay or to go, it amounted to the same thing." Such a typical attitude for him, but how drastically he was wrong. There is something deeply bitter about this course of actions. Camus seems to be berating those individuals who do nothing against the wrongness of society. By letting it pass you by, you are helping and therefore implicated in the crime. You may feel indifferent and innocent, but it is your refusal to stop the evil that is the most terrible crime of them all.