The Rhine and the TiberA battle over Holy Communion is brewing between German bishops and the Vatican. In the latest exchange between the Holy See and a German ecumenical study group known by its acronym ÖAK, Cdl. Kurt Koch, the Holy See's chief ecumenist, doubled down in an open letter (Monday) to Tübingen professor Volker Leppin.Leppin had lamented what he called the cardinal's "brusque dismissal" of his ecumenical group's proposal for an intercommunion free-for-all. Leppin is the director of the Protestant section of ÖAK, which the Vatican, last September, blasted for proposing in a study of "reciprocal Eucharistic hospitality" between...