Walter Kard. Kasper in Current Problems in Ecumenical Theology:
No Church can speak of several duplicates or branches of the one Church of Jesus Christ all having equal rights, without renouncing the claim of being truthful. Every Church that takes itself seriously, must start from the fact that – for all human weaknesses – the true Church of Jesus Christ is present in it. The Catholic Church takes the other Churches seriously precisely in that she does not even out the differences nor does she consider these differences as being of “equal value”, but she respects the other Churches in the otherness which they claim for themselves. In that sense she speaks with them “par cum pari”, on a parity level, “on an equal footing”.
(aus der Debatte um Geld ohne Gott)