Silver (or gold), while certainly tangible, is not 'useful.' You can't eat it or live in it. It's just a metal. It has no inherent value except people agree it has value. In this way it is no different than printed money. It is just heavier.
I agree GV's phrasing wasn't the best, but I don't know any printed currencies that are universally accepted as valuable the way PMs are.
I don't know of any precious metals that can be eaten, used as tools, shelter or weapons, or that provide warmth
Currency doesn't really need inherent value, it is only a temporary and portable medium of exchange. A gov't need not 'back' a currency as such, since I don't intend to exchange it for some (also inherently worthless) metal. I only need a portable exchange.
Say I have aspirin, you have eggs, I don't need eggs but you need aspirin. There's a 3rd guy that has firewood which I do need. You would have to go find him and that would only work if he needs your eggs, otherwise you need to get us all 3 together to perform the exchange at once. Huge hit to productive capacity in the economy all this resource shuffling and logistics, hence currency.
I only need the money long enough for my next exchange (whatever that is). It's not a 'store' of value and isn't intended as such. Even when I invest, stocks, bonds, whatever, that's not dollars-- it's *denominated* in dollars. Huge difference.
Take ADRs for example. Stocks of foreign companies that trade on our exchanges just so they're easier to buy for people with dollars. Those shares aren't suddenly storehouses of dollars, they're just *denominated* in dollars on our exchange.
Money is a medium of exchange. So-called 'hard money'-ers and goldbugs miss the premise completely.
Precious metals are just commodities (commodities in a bubble at that!)
I don't need a universally acceptable form of printed currency unless I'm trading with foreign economies. Domestically is all I trade with directly.
Anyway, the dollar, love it or hate it, is darned near this universally accepted currency anyway.