Money is not metal. It is trust inscribed. And it does not seem to matter much where it is inscribed: on silver, on clay, on paper, on a liquid crystal display. Anything can serve as money, from the cowrie shells of the Maldives to the huge stone discs used on the Pacific islands of Yap. And now, it seems, in this electronic age nothing can serve as money too.
– Niall Ferguson
The Ascent of Money (2008), pg. 30