In a world where we are so often told that the indomitable human spirit can accomplish almost anything, the response to catastrophes natural or otherwise, accidental or intentional, is that following every loss we can rebuild or recreate. Whatever falls can rise anew — or so the popular conviction would have it.

Likewise, in the realm of our mundane and material life, whatever breaks or wears out, can be replaced — often with something better.

We live in collective denial about the possibility and reality of irrevocable loss.

On Tuesday, President Emmanuel Macron pledged that France would rebuild the fire-devastated Notre-Dame de Paris cathedral:

“We will rebuild Notre-Dame even more beautifully and I want it to be completed in five years, we can do it,” Macron said.

“It is up to us to convert this disaster into an opportunity to come together, having deeply reflected on what we have been and what we have to be and become better than we are. It is up to us to find the thread of our national project.”

Healing, hope, and solidarity, require such an expression of a vision for the future.

Even so, this is also an opportunity to reflect on the nature of loss.

The timbers that just went up in flames came from forests that were lost long ago:

The wood for the soaring cathedral was first felled around 1160 to 1170, with some of it coming from trees thought to be 300 to 400 years old at the time they were chopped. That puts the oldest timber in the cathedral at nearly 1,300 years old.

Replacing those beams with comparable oak is simply not an option, said Bertrand de Feydeau, vice president of the preservation group Fondation du Patrimoine. Trees that supplied the roof’s frame came from primary forests—forests that are largely untouched by human activity, he said, according to the AP. He surmised that the huge trees associated with primary forests are gone too.

We live on a planet where we have lost so much — so many species of fauna and flora along with the habitats in which they once thrived — and we are in jeopardy of losing so much more in the decades to come.

Still, despite the mass of evidence to the contrary, we hold on to a fantasy of endless abundance.

The fact is, it’s impossible to truly appreciate life without facing death. We cannot protect a fragile planet without clearly seeing the full measure of our destructive behavior.

This world, the only world humanity will ever inhabit, is already on fire. The question isn’t just how much we stand to lose — we don’t even have a complete inventory of everything we have already lost.

The question is: when are we going to stop fueling the fire and instead with urgency and determination, turn our energy to quelling the flames?