Battle not with monsters lest ye become a monster and if you gaze into the abyss the abyss gazes into you.

Whoever battles with monsters had better see that it does not turn him into a monster. And if you gaze long into an abyss, the abyss will gaze back into you.

Battle not with monsters lest you become one.

Whoever fights monsters should see to it that in the process he does not become a monster. And if you gaze long enough into an abyss, the abyss will gaze back into you.

He who fights too long against dragons becomes a dragon himself; and if you gaze too long into the abyss, the abyss will gaze into you.

Whoever fights monsters should see to it that in the process he doesn't become a monster