One Charles de Fleury catalogued pieces of the true cross in the 1800s and found them to sum to 2% of a plausibly sized cross, not the oft-repeated claim that they add up to a large ship, or a nice house: https://en.wikipedia.org/wiki/True_Cross#Dispersal_of_relics paragraph 6. While perhaps biased, it does seem plausible that a cataloguing of such claimed relics today would add up to a similar total volume.

The famous John Calvin quote about relics comes from 1543, and many of the other quotes come from before 1000, while that catalogue is from the 1870.

In between comes the Protestant Reformation, more than a century of religious wars across all of Europe where one side in many cases actively sought to destroy relics and the gradual conversion to Islam of many densely populated Christian areas.

A catalogue from the 1870 is next to worthless for telling us how many relics existed in the early 1500s.

But everyone knows, that the number of relics increases over time. For each one lost, two new ones appear. So if we had 2% of the true cross in 1870, perhaps we had only 1% in 1543. Someone needs to update the catalogue. When we see how much we have today, we can estimate, when the cross crosses 100%. In the year 3451? (The Hobbes theory.)

> A catalogue from the 1870 is next to worthless for telling us how many relics existed in the early 1500s.

I thought we were talking about how many are on display? What does the number of fragments that existed in the 1500s matter?

The claim that you could build a house out of the fragments comes from the 1500s, so that's the number that matters if you're checking the veracity of that claim.

There are far less now that Protestants spent a century destroying purported fragments.

Since the fragments were said to come from a single piece of wood in Constantinople (see the article linked above), it is not that surprising that their sum would be reasonable. Clearer-cut and a little more entertaining are the thirty or more "holy nails:"

https://en.wikipedia.org/wiki/Holy_Nail

That said, I'd like to know the carbon date on those wooden fragments.

I suspect the saying comes from a time more in the past when many many false relics would abound. Once the fervor around them died off, any ones deemed fake would disappear from circulation and the total amount would dwindle.

Well, the total amount would dwindle.

> “And don't succumb too much to the spell of these cases. I have seen many other fragments of the cross, in other churches. If all were genuine, our Lord's torment could not have been on a couple of planks nailed together, but on an entire forest.'

'Master!' I said, shocked.

'So it is, Adso. And there are ever richer treasuries. Some time ago, in the cathedral of Cologne, I saw the skull of John the Baptist at the age of twelve.'

'Really?' I exclaimed, amazed. Then, siezed by doubt, I added, 'But the Baptist was executed at a more advanced age!'

'The other skull must be in another treasury,' William said, with a grave face. I never understood when he was jesting.” ― Umberto Eco, The Name of the Rose

And the buddha would have to have been 10 feet tall for all the relics in the various stupas of the world to be real.

Frankly though, I consider authenticity overrated.

I wonder how much fragments would be worth at auction (i'm sure Paul Allen tried and was denied)

Christopher Buckley (of Thank You For Smoking fame) did a funny book recently called The Relic Hunter that satirizes this situation in a Middle Ages context.