> If Donovan's observation were accurate, how can he explain humanity's long history with monetary metals. Gold and silver are still regarded by some as the only legitimate forms of money.
I'm not sure how true that -- money is precious metals -- has been throughout history. For example, if you look at coins from the past, they are all different weights and mostly made of greatly differing ratios of various metals and alloys. There were never really coins of uniform weight and until early modern times we didn't really have the technology to even mint coins with a uniform weight. Whilst the unit of account probably was some weight of precious metal, e.g. the weight in silver of a bushel of wheat (shekel), the issuers of these coins rarely offered convertibility to precious metals. Furthermore, the nominal value of the coins were typically higher than the intrinsic value of the coin, even for coins made from gold and silver. If the coins has a nominal value equal to or lower than the intrinsic value of the coin, then people would melt them down into bullion. So the assertion that the unit of account was a gold coin of a particular weight seems as unlikely as it is illogical. Instead, the coins typically represented a debt of the issuer valued at the nominal value of the coin. Even still, most people didn't even use coins. Kings would withdraw all coins from circulation to re-mint them and commerce would continue as usual because most people just used credit ledgers to transact with each other. Ergo, money usually always has been and will continue to be credit/debt. Gold is not money... it's a commodity, albeit a valuable one :)
From what I've read, it seems we only recently (since early modern times) developed an obsession with precious metals as money. Of course, we tried a gold standard but it ends up in deflation and misery for all involved so I don't suspect we will go back to it.