This is the question posed by today’s Vatican document. This declaration by Cardinal William Levada, head of the Vatican’s doctrinal office, may well occasion some controversy in the next few days, so it’s important to understand what it is really saying, and what it intends to accomplish. Ever since the reforms of Vatican II in the 1960s, and the ecumenical opening of Catholicism to other forms of Christianity, there has been something of a crisis in the Catholic esprit de corps. Before the Sixties, Catholics were generally forbidden even to attend, e.g., Protestant services; now the Pope himself was hosting Lutherans and Methodists. If it’s suddenly OK to be Protestant or Eastern Orthodox, why—many asked—be Catholic? What difference does it make? Today’s Vatican document is intended to clarify, especially for Catholics, the truth claim that continues to be made by Catholicism: that it constitutes the most faithful existing realization of what Christ intended when he founded a Church. This means, according to Catholic doctrine, that Protestant churches are not really the Church. Today’s Vatican document says: “These Communities [i.e., Protestant churches] do not enjoy apostolic succession in the sacrament of Orders, and are, therefore, deprived of a constitutive element of the Church. These ecclesial Communities which, specifically because of the absence of the sacramental priesthood, have not preserved the genuine and integral substance of the Eucharistic Mystery cannot, according to Catholic doctrine, be called ‘Churches’ in the proper sense.” This is the Vatican’s answer to the question, “Why be Catholic?”: In short, because Catholicism is more faithful to what Christ intended. Some will, no doubt, portray this as an arrogant statement, and one that represents a backtracking from ecumenism and Christian unity. But all it is, really, is a making explicit of what Catholicism really teaches. The cause of truth is not served by a failure to be honest on the part of Catholics—any more than on the part of, say, Landmark Baptists, who hold a similar belief that their denomination is the only one that technically qualifies as a “church.” Say what you believe—and then people of good will will try to sort it all out for themselves. And, as far as ecumenism is concerned, even today’s document makes clear that “there are ‘numerous elements of sanctification and of truth’ which are found outside [the Catholic Church’s] structure.” The Protestant churches “are deprived neither of significance nor importance in the mystery of salvation. In fact the Spirit of Christ has not refrained from using them as instruments of salvation.” As a Presbyterian who grew up Catholic, I view today’s Vatican statement as fundamentally an assertion that Protestants aren’t Catholics. Fair enough, and no cause for offense.