Nietzsche it is. Specifically, it's from Beyond Good and Evil. The first half of this aphorism goes like this: "He who fights with monsters ought to look to it that he himself does not become a monster." When I consider the whole piece (quote and art) they complement one another very well.

well seriously, Your art impress me a lot more than this snob lady I won't be speaking of(fans might be listening) Because as I explained, I cannot say I "see" the soul of an art, but some arts has an aura and some others are not, you got this touch to put this aura I like to see in arts very nice job, I never ever had the chance and material to ink...

O_o i know i'm probably saying weird stuff but doesn't gollum say something like that? in a swamp place ...amyway cool O_o

O.o that is really good!! i love the quote! its a little creepy!

I remember when you did this one. You should get this framed ^.^

Ooooh, I lookied at this earlier. So snazzy...? Okies, maybe not, but iz still good. ^^

interesting verse; you did a good job with the thick and thinness of the line; and the caligraphy is pretty nice too!