moral compass

noun3

1. •
   An inner sense that distinguishes right from wrong, functioning as a guide for morally appropriate behavior.

   • To every sane man in all climes and ages the great Creator has given a moral compass to enable him to avoid the wrong and follow the right. This moral compass we call conscience. — 1865
2. •
   A belief system, person, etc., serving as a guide for morally appropriate behavior.

   • [Philip] Hart is one of those rare men whose ego is smaller than his talents; and whose directness and sense of conscience have led others to regard him as the moral compass of the Senate. — 1975
3. •
   (no longer used) The full range of actions, vices, or virtues, which may affect others and which are available as choices to a person, group, or people in general.

   • [W]hile blowing opposite arguments from every point of the moral compass, the adventurous Baron quietly saw himself left to navigate his own vessel his own way, through this storm of his own raising. — 1822