"What is a monetary unit? What is a dollar? We do not know. All we do know for certain — and I wish to reiterate and emphasize the fact that on this point the evidence which in these articles I have only been able briefly to indicate, is clear and conclusive — all, I say, that we do know is that the dollar is a measure of the value of all commodities, but is not itself a commodity, nor can it be embodied in any commodity. It is intangible, immaterial, abstract. It is a measure in terms of credit and debt." (from "Broken Money: Why Our Financial System is Failing Us and How We Can Make it Better" by Lyn Alden) Start reading it for free: https://a.co/8CaXDbz