When the Notre-Dame fire began I was at the Sacré Coeur in the 18th arrondissement. It was a sunny afternoon, and crowds sat on the green before the church, making the most of the fine weather. Dance music was being played to a medium volume while a man with a football performed tricks at the top of the hill. A festival-like scene, this was Sacré Coeur as one of many tourist hot-spots. Busy, vibrant, unremarkable.

Joining fellow tourists in queuing to enter the church, we realised once inside that mass was being celebrated while some tourists milled around taking photos. As far as I could tell, those walking around were quiet, interested, respectful – but their presence, our presence, felt inappropriate at that time. Worshippers and tourists are equally welcome in a church, but it felt wrong to be there as a tourist during mass. We quickly left.

Taking in the view a final time before descending into the city, we saw the plume of smoke coming from Notre-Dame and the fireball inside at the base of the spire. Later that evening we joined the crowds by the Seine, looking on at the great cathedral in silent shock.

My recent work has made me think a lot about the nature of Christianity, secularism and cultural identity, and my experiences on that strange day in Paris brought the interaction of these three areas into greater relief, with cathedrals as the focal point.

The individual

Historic churches, like Sacré Coeur, are two places at once. They are a place of worship and a tourist attraction. Their history and beauty invite you to enter (the 13 million annual visitors to Notre-Dame attests to that).

The attraction for a Christian to a great church speaks for itself. Whether a local or a visitor, it is a chance to worship in a historic location with profound spiritual resonance. There is a reason why cathedrals are so impressive. They are themselves an immense prayer, a religious event, and for a Christian this is likely to be a charged atmosphere, and a personally moving experience.

For the non-Christian visitor, it is a place of secular wonder. Wonder in that the architecture of the building and the events it hosts are inescapably religious in register, transcendent and oriented to the heavens. Now, non-Christian of course means many things. It includes people of other faiths, but also lapsed Christians, atheists and people with varying levels of religiosity. In short, the range of possible responses to a beautiful cathedral is as varied as the people who enter it. But what they will have in common, I suggest, is that aforementioned sense of wonder, however unique to the individual that may be.

The collective

Watching the fire rage in Notre-Dame that evening was one of those rare historic events that unites those physically in attendance to each other and beyond, to those following the news elsewhere. A true, profound unity, not the unity of political-speak but something far more primitive and instinctive.

Some crowds are comprised of individuals doing their own thing – think Oxford Circus, or tourists inside Notre-Dame on a normal day – and then there are crowds with a singular focus. It is powerful being in such a crowd with a focus, whether at a gig, a game, or in the aftermath of a major event. You become conscious of the crowd as something you are connected to and truly a part of. You know that you are all, roughly, thinking about the same thing.

This was the unity provoked by the Notre-Dame fire, and it is the locus of a third sense of the sacred that I argue our cathedrals represent, which combines religious and secular characteristics.

Notre-Dame is so old as to seem permanent. For 850 years, through a turbulent history and with damage and modification along the way, it has been a world-famous landmark, an icon of France and Catholicism and Gothic architecture. When something permanent is threatened, something with a grand, formal importance but which is nevertheless abstract in our daily lives, it is jarring to us. If something so old and enduring is vulnerable, how much more vulnerable are we?

There are ongoing critical conversations about religion and the public sphere in Europe, the contested spaces and limitations of each domain, the politicisation of religion. This is the realm of everyday human life. But just as being inside Notre-Dame can silence noise and provoke simple reflection, distracting us from daily worries, so too did its fire still the diverse crowd outside.

Conclusion

Europe’s cathedrals are delicately balanced in more ways than one. Many are old and crumbling, many are being preserved and renovated. They are our inheritance from a Christian age and they continue to be cherished, by Christian and non-Christian Europeans and others further afield.

In this most secular corner of the world, cathedrals continue to pose religious questions to those who visit. In France, the home of secularism, Notre-Dame, the greatest of all the cathedrals, will pose those questions again as its restoration begins. Meanwhile, an enduring civil religion permeates the public sphere and moves us.