I interact with a wide variety of Catholics in my line of work, and, sad to say, not all of them are cheering representatives of the faith.

Recently, I ran across (not for the first time, sadly) a fellow who was pining for the “good old days” of casual anti-Semitism. He was a hard-bitten, reactionary fellow of the type that in fact despises where the tradition has developed to, despises the teaching of Vatican II and despises every pope since Pius XII (especially John Paul II).

He wants whatever is old merely because it is old. And so, for this guy, it is axiomatic that, since a lot of Catholics were in days gone by hostile to Jews, why then that must be part of “tradition.”

John Paul's beautiful gestures of love to the Jewish people (such as, for instance, his visit to the synagogue at Rome and to Israel and Yad Vashem) were, for this guy, a “betrayal of the tradition.”

Now what interested me about this fellow was that he voiced an idea many people share: The notion that anything old in the Church must, ipso facto, be part of the tradition.

But is this really so? After all, one of the oldest things in the Church is sin. We all do it and we all go to confession for it. Does it therefore follow that sin is “part of the tradition” and something to be treasured and preserved? Obviously not. So there are old things in the Church that are not necessarily a part of the Church. In short, we can speak of a sort of “shadow tradition” that is always present alongside authentic tradition.

Does this sound mysterious? It should. But it is a mystery already spoken of in the New Testament. St. Paul, for example, tells us the mystery of evil was already present and at work even in his day (2 Thessalonians 2:7). It remains a constant fact throughout the history of the Church and, because it is constant and very old, guys like my reactionary acquaintance can often think it is the same thing as the tradition.

The difficulty with the shadow tradition, like all evil, is that it is, as Lady Macbeth says of hell, murky. Evil doesn't show itself clearly. It prefers darkness, obscurity, ambiguity, fuzz, blur. Now and then we can catch a glimpse of it, briefly. Now and then, as in a lightning flash, we see evil in almost chemical purity: in an airliner smashing into the World Trade Center, in a heap of bodies stacked like cordwood at Dachau, in a child dismembered on an abortionist's table.

But typically, evil knows how to duck behind the legitimate moral ambiguities of life. And so the abortionist appeals to the tradition's respect for choice, the jihadist to the need for “tolerance” of his viewpoint and the Jew-hater the need to honor some “tradition.” Attempts to oppose the evil can then quickly be cast as attempts to oppose the good thing the evil hides behind.

Things can get muddled very quickly.

That, among other things, is why a magisterium is necessary, from time to time, to distinguish that shadow tradition from the tradition. For every now and then, someone gets the bright idea of asserting that the shadow tradition is the same thing as the tradition.

It happened in the fourth century when Arius said that Jesus, being the Son (and therefore not the Father, which is a legitimate part of the tradition) was therefore not God (which is not part of the tradition). Similarly, the Church's teaching that the covenant is no longer limited merely to Israel is a part of the tradition, but rejection of and malice toward Jews is a longstanding manifestation of the shadow tradition.

Why does all this stuff matter?

It matters because Catholics should take my reactionary friend's fond nostalgia for the “good old days” as a cautionary tale lest, in claiming to defend tradition, we find ourselves merely engaging in the worship of old sin and error and opposing Holy Church. The mere fact that something has been present in the life of the Church a long time does not necessarily make it apostolic tradition.

Anti-Semitism, though it has long been practiced by Christians of many stripes, including Catholics, is not intrinsic to the tradition, as the Second Vatican Council makes clear in Nostra Aetate. Now my more-Catholic-than-the-Pope acquaintance is left in the last place he ever thought he'd be: dissenting from Holy Church simply because he confused his reactionary ideology with orthodoxy and mistook the shadow tradition for the tradition.

Orthodoxy is coterminous with neither conservatism nor liberalism. These ideologies are the work of fallen man and share in his fallen-ness. Only the revelation of Christ through the teaching office of Holy Church is a sure guide.

Mark Shea writes from Seattle. Visit his Web log at www.markshea.blogspot.com.