Soon after his election, Pope Benedict declared restoration of the Vatican's ties with Beijing one of his priorities, along with reunification of the church on the mainland and the estimated 10 million Catholics there. His open letter to China's Catholics at the weekend is the Vatican's most serious overture to Beijing yet. It has gone to a lot of trouble to ensure the letter is widely circulated and understood, translating it into five languages including traditional and simplified Putonghua, and providing unusual notes explaining the main points. The letter does nothing to bridge the gulf over the Vatican's insistence on the Pope's prerogative to appoint bishops. But its conciliatory tone and gestures symbolic of wiping the slate clean break new ground. Hopefully it will help answer the Pope's prayers for more productive dialogue. The foreign ministry has reacted by reiterating Beijing's well-established position on Sino-Vatican relations. A leader of the official church on the mainland has said the Pope's letter is well intentioned. It will now be interesting to see whether Beijing responds with any action. The Vatican's scrapping of a regulation that discouraged members of the underground church loyal to the Pope from contact with clergy of the officially approved church is unprecedented. But it recognises the reality that the two have been moving closer together. The Pope's call for those who have suffered for refusing to join the official church to forgive and reconcile for the sake of unity should add momentum. Forgiveness and reconciliation, however, will test the charity of those who suffered the most from past repression. It is to be hoped that Hong Kong's Cardinal Joseph Zen Ze-kiun is right when he says the letter is a common starting point for dialogue. The sticking point remains the Vatican's insistence that the Pope's right to appoint bishops is fundamental to religious freedom and Beijing's view that this is tantamount to meddling in domestic affairs. In expressing trust that an agreement can be reached, the Vatican has in mind the arrangement in communist Vietnam, where it proposes a few names and the government chooses. Resolution of the dispute would be a victory for religious freedom on the mainland. It would do China's image no harm either.