The Vatican sought on Wednesday to downplay a document claiming the Roman Catholic Church was the "one true Church of Christ" after it provoked outrage among other Christian faiths.
Pope Benedict XVI restated on Tuesday what he said were the "defects" of Christian faiths other than Roman Catholicism.
The document focused largely on the Vatican definition of what constitutes a church, which it defined as being traceable through its bishops to Christ's original apostles. Thus, it said, the world's Orthodox Christians make up a church because of shared history, if "separated" from the "proper" Catholic tradition; Protestants, who split from Catholicism during the Reformation, are considered only "Christian communities."
The document reiterated church teaching that the Roman Catholic Church alone is the mediator of salvation, though other beliefs can be its "instrument."
It also repeated many of the contentious claims of a document called Dominus Iesus issued in 2000 by the Vatican office on orthodoxy, which Cardinal Joseph Ratzinger headed for more than two decades before being elected pope in 2005.
The 2000 version also drew angry reactions from other faiths, which accused the Vatican, and Ratzinger specifically, of being unnecessarily divisive.
The Vatican said the new document was aimed at clearing up "confusion and doubt" about the Catholic Church's relationship with other faiths. But it provoked a wave of condemnation from other churches.
A spokesman for Egypt's Coptic Church, the largest Christian community in the Middle East, warned on Wednesday that comments such as those expressed in the document "fan tensions and arouse negative emotions".
The World Council of Churches, which represents 340 churches including Orthodox and Protestants, insisted that "each Church is the Church catholic," using catholic in the sense of universal. The World Alliance of Reformed Churches -- which represents more than 200 Protestant churches -- said the document "goes against the spirit of our Christian calling towards oneness in Christ."
However, Cardinal Walter Kasper, who is responsible for the Church's relations with other denominations, said the declaration "does not say that Protestant Churches are not Churches, but that they are not Churches in the proper sense, that is they are not Churches in the way the Catholic Church understands the word Church."
Protestant Churches "do not want to be Churches in the sense of the Catholic Church", because they have different ideas of what the Church and its ministers should be, he said.
He added that setting out the remaining differences between the Christian faiths "should stimulate us and not be viewed as a catastrophe."