Moral compass

A metaphor for one's ethical values, based on the allusion, of course, to a compass that steers one in the morally right direction. First attributed to the British poet and novelist, Anna Maria Porter, in Roche-Blanche or, the Hunters of the Pyrenees, published in 1821. Charles Dickens later used it in Martin Chuzzlewit, chapter 4, in 1843.