Harry Potter. Pants on women. The size of your carbon footprint. Trick-or-treating. Recycling. Supporting public radio. Smoking. Home schooling. The theology of the body.

What does the Church dogmatically define for us when it comes to these matters? Nothing. And yet, depending on where you go in the Church, your views on these and many other matters will leave you a marked man or woman if they aren’t the “correct” views. You will be stamped and binned as anything from a “liberal Catholic” to a member of the “Catholic Taliban” by somebody if you do not reply to the probing question on these and many other matters with the correct shibboleth.

What’s a shibboleth? In the Book of Judges, we read about an incident in one of the countless acts of tribal warfare between the Israelites (specifically the tribe of Ephraim) and the locals (in this case, the Gileadites) during the conquest of Canaan:

And the Gileadites took the fords of the Jordan against the Ephraimites. And when any of the fugitives of Ephraim said, “Let me go over,” the men of Gilead said to him, “Are you an Ephraimite?” When he said, “No,” they said to him, “Then say Shibboleth,” and he said, “Sibboleth,” for he could not pronounce it right; then they seized him and slew him at the fords of the Jordan (Judges 12:5-6).

Gileadites, eager to root out the sinister subversive guerrilla warriors who were streaming across their porous borders from Ephraim, devised a simple plan: Ephraimites could not pronounce the “sh” sound. Make them say the password and, if they couldn’t say “sh,” kill ’em.

“Shibboleth,” then, means a code word that grants access to the Inner Circle.

The problem is that “shibboleth” carries another connotation — that of “prejudice over trivialities.” For “shibboleth” did not itself denote anything particularly important. It meant “the part of a plant containing grains, such as an ear of corn or a stalk of grain or, in different contexts, ‘stream, torrent.’” Its sole significance was not what it meant, but how people pronounced it. It’s the world’s earliest version of “You say ‘tomayto’ and I say ‘tomahto.’”

And, unfortunately, that’s a concept still very much active today in the sundry tribalisms we Catholics foolishly create as we divide the body of Christ over absurdities that are not essential to the faith. I have known Catholics who, for example, have been treated as false sisters and traitors to the faith for the crime of wearing pants. I have seen Catholics derided as everything from dupes to fools to heretics because they happen to have a taste for Harry Potter novels. I have seen parents labeled as dangerous, satanic and neglectful because they let their kids go trick-or-treating. I’ve seen Catholics reviled as fundamentalist fanatics and environmentally irresponsible because they’ve opted to trust God and have a large family. I’ve seen Catholics take abuse from other Catholics as false brethren because they happen to like the Beatles. I’ve seen Catholics with impeccable pro-life convictions and credentials dismissed as subversive enemies of the faith because they did not support the death penalty.

All these things are shibboleths. They are tribal markers that act as a substitute for hard thought by replacing it with Pavlovian responses to mere acoustic cues. The reality is that the Church has no dogmas about Harry Potter, no doctrines about trick-or-treating, no rules about pants, no conciliar or papal definitions about “Sergeant Pepper’s Lonely Hearts Club Band,” no dogmas about family size, and no zeal for the death penalty.

The only rule is: “In essential things, unity; in doubtful things, liberty; in all things, charity.” Shibboleths are the lazy man’s substitute for the hard work of obeying that rule.

Mark Shea is content editor of CatholicExchange.com.