Quote from: americanpegasus on September 21, 2015, 06:44:31 AM

Quote from: brg444 on September 21, 2015, 06:23:35 AM

I guess that is an interesting analysis but unfortunately not one I can agree with for the simple reason that bitcoins are absolutely and unequivocally fungible.

All I have to do is point to the time when the community agreed not to accept stolen coins from an exchange to totally destroy that argument.

Bitcoins are not fungible because they have unique histories. All swords start off identical as well, but if *this* sword has been wielded by the King of England in battle and *that* sword was taken off a dead thief after it was cursed by the local witch doctor... Which sword do you think will be more valuable?

Similarly, if *this* bitcoin is one of the original bitcoins Satoshi held, and *that* bitcoin was stolen from an exchange after being transferred there from the Silk Road, which coin will be more valuable?

This chasm will only increase as time goes on... Eventually we may see nations ban entire swathes of 'tainted' bitcoins.

True fungibility is needed for a worldwide currency, and unfortunately bitcoin doesn't have it.

Bitcoin was amazing, and world changing - no one is taking that away from it. It may also carry value for a long time to come. But Monero is the first true digital money and you are extremely lucky to be hearing it about it now - and not in 2017.

I understand where you are coming from but, again, it appears to me that you are conflating subjective perception of value (or user preference) with fungibility.

First let us examine the term we are debating and its etymology so that there is no ambiguity:
"New Latin fungibilis, from Latin fungi to perform"

Therefore what we are concerned with is whether or not one satoshi performs the same function as any others. It seems to me that for all practical purpose they do and that Bitcoin makes no distinction between any of them.

In fact, I would suggest an individual would be hard pressed to himself distinguish one satoshi from another. Consider this thought experiment:

Let us pretend I am in control of a wallet which holds a certain number of coins, using your example, stolen from said exchange.

I also happen to own a couple of what you would consider "clean" bitcoins. To illustrate my point I choose two spend two outputs, one "clean" and one "tainted", to the same input.

Looking at said input, can you tell which satoshis are "tainted" and which are not?

I'm sorry but I seemingly cannot wrap my head around this "chasm" you speak of for the simple fact that as Bitcoin adoption grows it is inevitable that satoshis will cross paths with what you call "tainted" coin, so much that at one point one could probably suggest that a majority of bitcoins in circulation have come in contact with "tainted" coins.