This weekend the nave of Manchester hosted three metal bands, again with the setup emulating a rock concert venue as closely as possible. One of the bands had a blasphemous name, and the lyrics went beyond the cheeky glorification of fornication on the playlist at the silent discos. I'll let you do your own research, but the first set of lyrics I came across described someone being dismembered.

In defending these choices of how to raise funds to run cathedral operations, cathedral deans have given a string of managerial banalities which presuppose that cathedrals are just big buildings which the Church sometimes uses for sacramental functions, as if by an accident of history. There are two fundamental disagreements between cathedral deans and their critics. The first is over whether cathedrals are sacred -- set apart from the world, for God. The second is over whether cathedrals are sacred enough, and dancing drunkenly to Eminem and Vengaboys is profane enough.

On the theology of the sacred, David Monteith, the Dean of Canterbury, has offered the press the insightful remark that "views on the nature of the sacred differ". This is true, but trivial: what matters is whose view is true, or at least reasonable. So, are cathedral naves sacred spaces?

Cathedrals are the seat from which sound doctrine is defended, but they are also dedicated for the celebration of the Eucharist. Officially, the Church of England teaches the Real Presence: that Christ's body and blood are really there, at least until consumed. The generations of clergy, masons and carpenters who dedicated their lives to building our ancient cathedrals had robust conceptions of the Real Presence, as do thousands of Christians across denominations in England today. Christians have always understood the shedding, and hence drinking, of Christ's blood to be the perfection of the atoning sacrifices celebrated in the Temple of Jerusalem. So the nave of a church is at least as sacred as an outer court of the Second Temple. Given the way the Temple's outer courts were treated by Jesus and His Apostles, the current treatment of cathedrals is not consistent with the Biblical witness.

But we should also think of the history of these buildings and what they represent to us, both to the faithful of England and to wider society. At Canterbury, DJs hollered and bopped yards from where Thomas Beckett's blood poured out on the flagstones defending the transcendence of the Church above worldly power. Most of us, including non-Christians, have a concept of the sacred, and want to live in a society where some things are understood to be more important than fun and profit. There are only limited activities we would tolerate at a war memorial. Ironically, the legal test for whether an activity is allowed at a graveyard is whether it would be allowed in a church.

The second disagreement is about where to draw the line on what to do in a nave, other than worshipping God or visiting to find out about Christianity. Here, the remarks offered in defense of the silent discos betray a dishonesty that moots the search for a clear threshold.

On the one hand, appeals to the supposedly dire financial position of cathedral chapters are invoked -- if these are desperate times, then the discos must be desperate measures. That argument acknowledges that the night club role is especially regrettable, never mind that the governor of the Church of England, the celebrity philanthropist Charles Windsor, has a net worth of around £88 million.

On the other hand, we hear that running a night club is no different from any other form of "community engagement". It's insisted, without evidence, that cathedral naves have "always," been used for secular activities on behalf of the general public. This ignores the difference between the demographics and built environment of cities when the cathedrals were built, and the modern city. Those with no connection to the Church have any number of other places to get drunk and dance.

Defenders have argued that cathedral chapters would be unfairly policing taste if they drew the line at discos while hosting orchestral concerts. This argument implies that chapters already thought those concerts were too naff to give praise to God. If used by a dean, it is an admission of unfitness to serve. One of the roles of a cathedral dean is facilitating suitable music for the liturgy. If they think aesthetic judgments can't or shouldn't be made about what kinds of music belong in a cathedral, then they can't do their job.

If we think there is any threshold of appropriate activities at all, Manchester's satanic and violent music clearly crosses it. And if 90s cheese doesn't, doing nothing now will encourage worse later. Monteith has admitted in interview that legality is his only threshold for what might go on in Canterbury cathedral.

So, what can you do? The answer is not: persuade people who hear only money. What you can do is penance on their behalf; and prayer for the conversion of England, so that we are one day numerous enough to fill our ancient cathedrals with reverent song, and maintain them through routine tithing. Local parishioners are organizing prayer vigils during the discos, to achieve this, and to do so publicly, so that everyone who thinks there are more important things than money and entertainment can see they are not alone. If you would like to check whether there is a cathedral being desecrated near you, and get in touch to volunteer or just check details to turn up, please visit sacredmatters.carrd.co and email cathedralvigils@gmail.com.