"If something uncharitable is said about someone in your presence, either speak in favor of the absent or withdraw, or if possible stop the conversation."

Saint Jean-Marie Vianney, On love for one's neighbor.

Attend to this fact: in such a situation, either we act to stop the sin or we become a party to it. This is an example of how Christian courage (contrary to a worldly or Nietzschean evaluation of Christian virtue) is vigorous and demanding.

Also, when he says "love of neighbor" here, he does not mean only the absent person whose good name is being attacked. Love of neighbor here means also love of those who are entering into this sin. By acting to stop it or to contradict it by speaking in favor of the absent, we love also the neighbor who is speaking without justice and charity toward another.

- Fr. D.B. Thompson