The value of those shoes can't be destroyed by the government printing presses.
Yes, but their illiquidity makes them a poor medium of trade.
I don't understand your comment implying parent has no economic understanding. It sounds like his understanding of economics is what is driving his issue with paper currency.
I'm sure you're right, on both counts.
The OP is flat-out wrong regarding the constitution. The word "gold" appears exactly once, prohibiting the states from coining their own money. It's left to congress to "coin money and regulate the value thereof", full stop. Simple words, not scare tactics.
It's impossible to explain even a tiny part of one Econ 101 lecture in a /. comment. Reference material isn't hard to find for anyone interested enough to want to learn.
The value of money, like anything else, is subject to supply and demand. As the economy grows — through population and productivity — the money supply has to growth with it. If it doesn't, the value of money increases, which by definition is deflation.
(Even gold bugs have to agree with that proposition because they're always the ones talking about the opposite: "debasing" the money i.e. inflation.)
Deflation is a whole subject its own. The basic problem is that banking stops because interest rates are (again, by definition) negative, and no one will deposit money in an account that pays negative rates. It also means your mortgage payments effectively increase, because the bank has the money and you're selling your crops (or earning your wage) at ever-decreasing rates.
The basic problem with the so-called gold standard is that there's only so much gold. The gold supply can't grow with the economy, forcing deflation and its attendant deleterious effects. That effect is more pronounced the faster the economy grows. In the 19th century the US economy experienced high growth — through both immigration and productivity growth as a function of the Industrial Revolution — and in fact suffered four depressions (culminating of course in the Great Depression early in the 20th). These were all in part attributable to the inability (and lack of understanding for the need) to increase the money supply.
But don't take my word for it. We haven't had a depression since 1937. Living standards have improved, measurably, in many ways. The system has flaws, sure, but it works. By contrast, no country has a gold standard today. That doesn't mean it's untested; it was tested by many countries over many years, including by the US. And was found not to work! A simple, obvious, plain fact the gold bugs choose to ignore.