But anything worth $20 can be exchanged for that promise if the parties agree.

This system of fiat money has simply been accepted because it is convenient. The biggest problem with the paper(fiat, backed by nothing) system, you can not store the fruits of your labour. I am a "worker" and as such I toil daily for my survival. Right now I am still able to work and would like to do some extra labour so as to be able to put aside some of those "ERGS" to be saved until I am old and unable to work anymore. Gold is one of the rarest and versatile elements on the periodic table. It cannot be created or destroyed and as we have witnessed on this forum it is not easy to extract from the earth. each gram of gold represents vast amounts of "EGS" and capital before it sees the light of day. I can't speak for you, however I do not accept the concept that allows the "priveleged few" (who sit at a desk and do nothing useful for mankind), to have a printing press that allows them to trade useless paper for my hard work.

One might ask why the politicians, academics and the money changers prefer the fiat paper over paper backed by something of value. The answer is simple, they don't have any "ergs" to with which they can trade for gold. Having a paper system allows these scoundrels , with one stroke of a pen to confiscate all of the stored "ergs" on the planet, enriching themselves at the expense of the other 99.9 % of us.

http://www.youtube.com/watch?v=Dc3sKwwAaCU

I conclude by saying that if money is what "THEY" say it is, it is time for us to get educated and send people to government that wil restore a system of money that will treat the common man more fairly.