We have been led to believe that it is necessary and in the order of things to bully people into accepting the money issued by their own country. Well, it is not, period.
The harsh truth is, legal tender is a monopolist and totalitarian imposition to be demolished; if a medium of exchange and payment is good, it is wanted and hence there is no need to impose it by force; if force is needed to impose it, then it is not wanted and hence it is not good.
The general rule of thumb is: ruling a money legal tender rules its fraudulent nature, too, and that’s that.

We’re facing here two relevant issues: The obvious issue is that law is exposed to be exploited for the purpose of abuse and injustice. The less obvious issue can be detected by observing, figuratively speaking, paper money with a magnifying glass until two of its qualities – token money and legal tender – come into view, and then inspecting them more closely and carefully until they show up as they actually are: altogether distinct and separate.

When banks issued their own banknotes under free banking, you were free to accept them in payment or reject them, just as you are free to accept in payment or reject someone’s promissory note. The point is, you were free.

One thing is the form of money: what it is made of, and whether it does have intrinsic value or not. Quite another thing is whether you are free to accept it or reject it as payment.

Truth is, up till now I used the term “fiat money” incorrectly. And quite certainly I’m not alone in this. The incorrectness consists of confusing the two qualities of token money and legal tender as if they were a single indistinct quality.

A token has no intrinsic value, its sole value is symbolic; and that is what paper money is: no intrinsic value, only nominal. But whether you are free to accept it or refuse it, or forced to accept it, well, that is quite another thing, which has nothing to do with its intrinsic or nominal value: even though you may be more willing to accept as payment something having intrinsic value than something having only nominal value, you may nonetheless be free to accept it or not regardless of its intrinsic or nominal value.
Well, to be precise, we may also mention that both these qualities are separate from a third quality labelled “receipt money”: both fiat money and receipt money have no intrinsic value, both are based on trust and agreement, but the latter is agreed to be directly redeemable in some actual value.

Now, freedom means that you and I and our fellows, as parties in our agreements, pacts and contracts, are free to agree all the terms – all of them, payment and non−fulfilment included –: what is accepted in exchange for what, how an obligation is fulfilled are freely agreed upon by the interested parties; and if that payment or obligation is not fulfilled in those agreed upon terms, the payment or fulfilment did not occur and that’s it. Then legal tender enters the scene, and that freedom is undermined.

Legal tender means that you cannot refuse to accept legal tender in payment or in fulfilment of an obligation. Legal tender means that legal tender cancels out the obligation: an obligation fulfilled in legal tender is fulfilled to all intents and purposes. Legal tender means that not only an obligation in your favour fulfilled in legal tender is fulfilled to all intents and purposes, but also that you cannot refuse its fulfilment in legal tender. And this canceling out to all intents and purposes that you cannot even refuse means that you are deprived of any other claims for the obligation whereby not fulfilled in the originally agreed upon terms.

Conceptually, you are owed something, you receive something else, and you are forced to accept that something else instead of the something you are actually owed. For our purposes here the two parties of a contract agree freely; if the agreement is not free this is a matter of another sphere of justice outside the monetary sphere. If the party suffering the unfulfilment of the contract is appeased in the freely agreed terms of the contract itself, this is certainly closer to justice than appeasing it forcibly in the extraneous arbitrary terms of a legal tender dictated by a third party. Concretely, you are owed potatoes, and even if the contract provides for carrots in the absence of potatoes, you are forced to settle for a piece of paper and shut the hell up.
Incidentally, this is also another way to reward the demerit of the defaulting party instead of the merit of the injured party.

The various money features discussed above all contribute to let us take legal tender for granted. As a consequence not only we get used to using legal tender as sole unit of measure in agreements and contracts, but also to agree with the idea that obligations fulfilled in legal tender are fulfilled. All this does is playing in the hands of the holder of the monetary sovereignty issuing fiat money out of nothing, be it a government or the fractional reserve bankers, those bailees disguised as debtors, by not only legitimising their fraudulent practice of passing off promises as deliveries, but also shielding it with the force of law.

But there’s a second side of it, too: legal tender does not enter our agreements merely as a unit of account, but actually as an enforced and abitrary spurious third party insinuating, intruding into the free relationship between the contracting parties, ready to serve as a Trojan horse. Needless to say, in fact, the power ruling that something is legal tender simultaneously rules that the obligations in its favour better known as taxes are to be fulfilled in that same legal tender.

You may object, so what? Wait till you see this and the other gears meshing… So let’s see how government and law are the tools of puppeteers to monopolise the philosopher’s stone; let’s call it “moneypoly”: the monopolisation of moneypulation…

It begins with government demanding payment of its taxes in its legal tender, which is a first abuse; this sort of closes the cycle of monopoly, and is but the economic implementation of domination by force.
Leave aside for a moment who owns legal sovereignty and monetary sovereignty; whoever criminal is your creditor, the moment you are burdened by a debt and you are bound to repay it in something issued by the creditor, you’re screwed for good. Remember the changeover from fertile to infertile media of payment? If I lend you some seeds, even if I lend them at interest, you sow them, they fructify and produce more seeds, so after you’ve returned me my seeds, even though increased by the interest, much more are still left and we all succeed. If I have the monopoly of creating money and lend you some at interest, first you have to accept money from other people in exchange for your products in order to have that whom you have to return me, and second you must give me something that I want from you to get from me that additional money for the interest. In other words, welcome to the infinite debt trap. The bottom line is, the moment you owe me something and that something you have to get from me, you’re mine.
Just in passing, this is also demonstrated by what someone has keenly observed and someone else has foully exploited: making something mandatory drives its value artificially up, whatever that something is. And it drives the value of the other things artificially down in comparison as well, starting with its competitors, such as mandatory valueless money does to intrinsic valued money. All forms of the same fraudulent wealth transfer. And what drives its value up is nothing more than the gun to one’s head.

Imperialists and colonisers know and use this despicable dirt trick regularly to implement their exploitation: once I have invaded you, I kindly ask you at gunpoint to use my money, paying the taxes I wring out of you included. Legal tender is the economic implementation of sheer force as the source of law, and that force is only as possible and strong as its victims agree with it, even though only passively.
And once again the importance of the agreement and monopoly factors helps to highlight the relationship between monetary sovereignty and legal tender: monetary sovereignty with fiat money is the faculty to create purchasing power out of nothing and legal tender is the agreement of the victim to acknowledge this purchasing power, whatever way such agreement is produced, at gunpoint or by fraud, deceit or manipulation. The point here is that the first is powerless without the second: as to agreement, the criminals may create all the fiat money they wished but it would never become purchasing power unless and until the victims agreed, even only by not dissenting; as to monopoly, if legal tender laws and practices did not set up the monopoly of monetary sovereignty, the victims would be free to choose between that fiat money and its possible competitors.
Speaking of imperialisms, colonialisms, nationalisms and other such “isms”, not only we have already learned for good that the answer to any war among the poor is never to compete for a pile of bones but is rather to track the meat; it is also worth to highlight here how monetary nationalism is but a tool to these aims: individuals acting as third parties twist the roots of life from brotherhood to enmity, twisting ethical nationalism as responsibility for one’s area into non−ethical nationalism as irresponsibility towards anybody else’s areas, and then not only use it to fool and turn us all against each other, but chiefly as the international form of legal tender. The stronger the legal provisions against the use of other nations’ moneys, the lesser our freedom to make them compete for our trust.
And indeed the same applies to any alternative form of money.