Derek claimed to be quoting someone when he wrote, "The Very Powerful and the Very Stupid have it in common that they alter facts to fit their viewpoint. That is a problem when you are a fact that needs altering." It may have been someone important, but the name was scribbled out. It was on the same page as his pondering about what you know when you look at a Blockchain Ledger.

The Münchhausen trilemma: there are three ways of completing a proof:

• The circular, Coherentist, argument: proof of a proposition presupposes the truth of that very proposition
• The regressive, Infinitist, argument: proof requires a further proof, ad infinitum
• The dogmatic, Foundationalist, argument: accepted precepts are asserted rather than defende

The trilemma: deciding which of these three equally unsatisfying argumentation options gives knowledge.

In contemporary epistemology, the coherentist, foundationalist, and infinitist positions underpin what it is for something to be knowledge and, so, determine what kind of argument will determine what is purported to be known. It is unhelpful, for some people that Münchhausen Syndrome - a factitious disorder imposed on self or others - exists. Münchhausen Syndrome is about faked illnesses for ulterior motives. The Münchhausen trilemma is about knowledge.

When looking at a Blockchain Ledger, you can look at the Root Block. There are no prior blocks and so the only way to examine what it is that you know about the Root Bloc is to reject the Infinitist argument. Which leaves the Coherentist or Foundationalist arguments as a dilemma. When looking at the latest, the Terminal Block, the most newly minted block, the only way to examine whatever it is that you know about that block is to reject Coherentist arguments, leaving Infinitist or Foundationalist arguments. When looking at some Intermediate Block, between the Root Block and the Terminal Block, the only way to examine whatever it is that you know about that block is to reject Foundationalist arguments, leaving Coherentist or Infinitist argumentation. For Derek, the Blockchain Ledger reduced the Münchhausen trilemma into three dilemmas which all depended on which Block in the Chain you were examining.

Which is how Derek came to be quoting someone he could either not remember or did not want to remember or did not want to mention. The idea that facts are, somehow, fungible only really occured to Derek because Time Travel enabled similar considerations. That to travel to the beginning of time would be akin to being the Root Block and so on. The reality that Derek was examining was a reality where knowledge rapidly vanished or appeared depending on where one was.

It was a reality in which facts could, apparently, cease to exist and everything becomes a matter of opinion.

Which would be a horrifying experience if you happened to be one of those facts. Imagine becoming someone else's opinion merely because you mistook the present for the past. A kind of ontological Münchhausen Syndrome: reality that is only justified by the principle of "The Circular, the Regressive, or the Dogmatic: select two of three. Fight."

The idea that the Blockchain is about knowledge makes little sense to people who only really consider the Terminal Block: the Block that does not yet have value because it is in the Future. Indeed, the idea of the Terminal Block only relates to the general Blockchain, in terms of value that will be realised is a way of altering facts to fit a viewpoint that works if the value in the blockchain is clearly fungible. The Terminal Block is an exercise in Fiat Currency, from that viewpoint.

For Derek, travelling back to 1960 with a bunch of ten pound notes was always just a mote away from considering all of Time to be simply the Terminal Block. Which might actually be a mistake. The reality of the journey was that a Pub Crawl in the 1980s would, in fact, be a complex form of Non-Fungible Token. True, it would be possible to sell tickets to the individual, historical, events. And, even, to do so using a Block Chain with Non-Fungible Tokens. But the reality would be that the Non-Fungible Tokens would be a symbolic transaction. To really understand Non-Fungible Tokens, as things that are not simply a vehicle of speculation, there needs to be some underlying reality. Such as a Pub Crawl, in the 1980s, in Leeds. It requires some underlying thing and that means, in a very significant way: Non-Fungible Tokens are not Fiat Currencies. They are, in fact, Knowledge Transactions.

If your belief is that you can travel to 1987, on some Thursday, to down a few pints of Tetley's brews in a Pub in Leeds, then sceptics are going to demand proof, because this is 2021. Sceptics are going to demand that you provide them with knowledge. Which means engaging with the Münchhausen trilemma in a serious manner. You could show them your Time Machine, but then they might mug you. What you need is a Zero Knowledge proof of the journey. Which means providing some underlying reality. Which is as far from fiat - faith - as you can get. The Münchhausen trilemma only really covers one aspect of the matter: justification. The underlying reality needs to also be believed and true. There really is no substitute for a bar of gold when inventing a currency. Which is odd, since the overwhelming majority of Currencies are fiat. For Cryptocurrency, the closest thing to gold is the Electricity Bill.

The reality is that DOGE, for example, created a community which was committed to doing social things. DOGE would be the perfect vehicle and network for building Non-Fungible Tokens for Time Travellers. DOGE, underwritten by Pub Crawls in Leeds in the 1980s, might sound like a joke but the reality is that there really only needs to be a single Cryptocurrency for Fungibility. For Non-Fungible Tokens, there is a need for a lot more than just faith that you can exchange one coin for another. That is little more than FOREX trading as has been done for hundreds of years. DOGE began the shift away from the purely fiat nature of Cryptocurrency with slogans like "One Doge will always equal One Doge".

The Secret is in a Caravan in Wales.