moral compass
[mawr-uh l kuhm-puh s, mor‐]
noun
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. 2019