There are markets and systems of debt arrangements that predate currencies. Exchange is not predicated on the use of currency as a technology. Currencies have h

There are markets and systems of debt arrangements that predate currencies. Exchange is not predicated on the use of currency as a technology. Currencies have held sway for a very long time however because they are an exceedingly simple and elegant solution for a fiendishly complex problem. These days however we have a global network of universal turing machines attached to an increasingly large array of robots, and so things that are not algorithmically possible to do in a monetary system are now completely feasable and some of them may have considerably less friction.