"When you stare into the abyss, the abyss stares back at you."

I took it to mean that people tend to be effected by what they focus on. Such as cops who spend all their time investigating criminals and then becoming desensitized to crime and eventually engaging in it themselves. Or soldiers that end up committing war crimes to stop the enemy from committing war crimes. Stuff like that.

But certainly your interpretation also seems true.

 

I don't know what he meant by it, but I'll take a crack at it. If you focus too much on the meaninglessness of everything, then in your eyes, you're only observed by the meaningless. As social beings, that would give us no meaningful method of validation, and that is (or can be, at times) depressing.

 

I think it means that if you look deep enough into yourself you find Nothing. And this realization can drive you mad.

Compare: "Nothing is true. Everything is permitted." -- Old Man of the Mountain.

 

that, too.

 

I know the quote, and Nietzche has grown on me (I love The Birth of Tragedy), but I don't actually know the philosophical significance of the quote. I'd love to hear people's thoughts, though.

 

I'd actually argue that he was one of the most anti-Nihilist philosophers in the West. And he explicitly rejected sinking into depths of depression.