Protestants are often at a loss to know what is tradition in Roman Catholicism, and where to find it. Is it what is always and everywhere believed? Or is it what the current RC teaches?
Let’s take one example concerning the Lord’s Supper, the Eucharist. Now the Eucharist is absolutely central to the RC spirituality. For instance, Eucharisticum Mysterium (May 25, 1967), says this: “The mystery of the Eucharist is the true center of the sacred liturgy and indeed of the whole Christian life.” When one considers the vital importance of the RC self-understanding of the RCC as the extension of the Incarnation of Christ, this becomes a natural conclusion. It would appear, then, that the actual practice of the Eucharist is a vitally important aspect of the RCC.
The problem is this: when it comes to the laity, and whether they can participate in the cup, the RCC has changed its position twice, and in the opposite direction both times. The early church gave the cup to the laity. When the doctrine of concomitance arose in the Middle Ages (concomitance is the doctrine that the entire Christ is present in both the bread and the wine, so that receiving either one receives the whole Christ), the cup was withheld from the laity, mostly because of fear of spilling. Vatican II restored the cup to the laity once again. Was it tradition that developed the doctrine of withholding the cup from the laity? Was it tradition that restored the cup to the laity? If tradition is infallible, then how can it reverse itself? According to the first edition of the New Catholic Encyclopedia, tradition is basically what the current church says: “Tradition is the communication by the living Church of the Christian reality and the expression, either oral or written, of that reality.” St. Vincent of Lerins’s definition, however, is quite different: “Now in the Catholic Church itself we take the greatest care to hold that which has been believed everywhere, always and by all.” In context, it must be noted, he was talking about tradition, particularly in terms of interpretation of Scripture. These definitions of tradition cannot both be correct. Whose is correct, and how does the RCC determine this? Roman Catholics cannot agree on what tradition even is. The result is that private interpretation of what that tradition is and what is included winds up carrying the day. The only way that the RCC can be consistent, in my opinion, on the definition of tradition, is to go with the New Catholic Encyclopedia’s definition, in which case, tradition has contradicted itself in the matter of who gets the cup: tradition, defined as what the current church teaches, taught in the early church that everyone gets the cup. After concomitance, it taught that the laity cannot receive the cup. Now it teaches that the laity should receive the cup. These decisions were all reached through official Roman Catholic documentation.
The truth of what tradition is, then, is able to change over time. The New Catholic Encyclopedia explicitly says this: “Tradition that is living and dynamic must, by the law of life itself, undergo change.” If that is so, how can it have a divine element, which would (presumably, at least) be unchanging?