Morality Games 297 1990), avoidance of guilt (Cain, Dana, & Newman, 2014; Dana, Cain, & Dawes, 2006; DellaVigna, List, & Malmendier, 2012), anticipation of reputational benefits or reciprocity (as Plato’s Glaucon suggests, when he proffers that even a pious man would do evil if given a ring that makes him invisible; Trivers, 1971). At the extreme, this amounts to asking if saintly individuals such as Gandhi or Mother Teresa were motivated thus, or if they were “authentic” altruists who did good without anticipat- ing any reward and would be altruistic even in the absence of such rewards. Certainly, religions advocate doing good for the “right” reasons. In the Gospel of Matthew, Chapter 6, Jesus advocates, “Be careful not to practice your righteousness in front of others to be seen by them. If you do, you will have no reward from your Father in heaven,” after which he adds, “But when you give to the needy, do not let your left hand know what your right hand is doing, so that your giving may be in secret. Then your Father, who sees what is done in secret, will reward you.” The Envelope Game suggests authentic altruism is indeed possible: By focusing entirely on the benefits to others and ignoring the benefits to themselves, authentic altruists are trusted more, and the benefits from this trust outweigh the risk of, for example, dying a martyr’s death. Moreover, this model helps explain why we think so highly of authentic altruists, as compared to others who do good, but with an ulterior motive (consider, as an example, the mockery Sean Penn has faced for showing up at disaster sites such as Haiti and Katrina with a photographer in tow). Principles. Why do we like people who are “principled” and not those who are “strategic”? For example, we trust candidates for political office whose policies are the result of their convictions and are consistent over time and distrust those whose policies are carefully constructed in consultation with their pollsters and who “flip-