A hundred and fifteen men have descended on Rome to choose a new pope. For the Catholic Church's adversaries, as well as its anxious or disgruntled followers, there is hope for reform and renewal in the Church. Or maybe at the end of this conclave, there will just be a new pope.
Dr Hans Küng has long argued that profound reform is essential to the Church's survival, and his critiques of the Church and the papacy carry more weight than most.
Küng is the last surviving theological advisor to the Second Vatican Council of 50 years ago. He is still officially "a Catholic priest in good standing," but the Vatican stripped him of his authority to teach Catholic theology, following his critique of the doctrine of Papal Infallibility in the 1970s.
Nevertheless, he remains one of the world's most respected and widely read theologians. Küng is the author of about 30 books, including Infallible? An Inquiry, Freud and the Problem of God, Does God Exist?, Dying with Dignity, and Why I Am Still a Christian.
It's a list of titles that reflects his wide-ranging interest and grasp of the intersections of theology, philosophy, ethics and contemporary life.
Today, Küng is the president of the ecumenical organization, the Foundation for a Global Ethic and the emeritus professor of ecumenical theology at the University of Tübingen in Germany.
In his wide-ranging and frank interview with Michael Enright, Küng talks about the need for renewal, including an end to celibacy and a greater role for women in the Catholic Church.
He also emphasizes the problems inherent in the former Pope Benedict continuing on as a "shadow Pope", and talks about why he remains a Christian and a Catholic, despite his fundamental disagreements with the Vatican. Küng wrote about these issues in a recent op-ed piece in the New York Times.
To hear the radio interview: Hans Küng on the need for a 'Vatican Spring'