And If You Gaze Long Enough

The second half of Aphorism 146 in Beyond Good and Evil (1886), Chapter IV ("Maxims and Interludes"). In the original German: "Und wenn du lange in einen Abgrund blickst, blickt der Abgrund auch in dich hinein." It follows immediately from Nietzsche's warning about fighting monsters, together forming a single aphorism about the corrupting effects of sustained engagement with darkness. The "abyss" connects to Nietzsche's broader project in the book: the collapse of traditional metaphysics and morality leaves a void — nihilism — that can swallow the observer who stares into it without the creative will to generate new values.