On ne se venge jamais si bien que par le mépris.

A French maxim attributed to the 17th-century writer and courtier Roger de Rabutin, comte de Bussy, reflecting aristocratic moral and social codes where reputation and self-control were prized.

The idea is that the most effective response to an insult or injury is not retaliation but refusing to grant it importance; showing contempt (or indifference) denies the offender the satisfaction of provoking you and preserves your dignity.