the Vienna Circle and C. L. Stevenson, though first defended by Axel Hägerström in the early 1900s, suggests that ethical sentences are primarily emotional expressions of one's own attitudes and are intended to influence the actions of the listener. Under this view, "Killing is wrong" is translated as "Killing, boo!" or "I disapprove of killing."

A close cousin of emotivism, developed by R. M. Hare,