moral compass

[mawr-uh l kuhm-puh s, mor‐]
noun
  1. an internalized set of values and objectives that guide a person with regard to ethical behavior and decision-making: a rebellious teenager without a moral compass.

Origin of moral compass

First recorded in 1840–45
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018