Hans Küng (born 19 March 1928) is a Swiss Catholic priest, theologian, and author. Since 1995 he has been president of the Foundation for a Global Ethic (Stiftung Weltethos). He is notable for his rejection of the doctrine of papal infallibility. Although Küng is not officially allowed to teach Catholic theology, his priestly faculties have not been revoked. In 1979, he had to leave the Catholic faculty, but remained at the University of Tübingen as a professor of ecumenical theology, serving as an emeritus professor since 1996.