Who said "The good is no longer good when one's neighbor mouths it."?

This quote is attributed to Zarathustra.

The good is no longer good when one's neighbor mouths it. - Zarathustra

"The good is no longer good when one's neighbor mouths it."

Zarathustra

Character in Thus Spoke Zarathustra

"I teach you the Übermensch. Man is something that shall be overcome."

"One must have chaos within oneself to give birth to a dancing star."

"The snake that cannot shed its skin perishes."

"I love those who do not first look behind into the past before they look down at the abyss."