You pay your debts (for whatever you buy) with paper that the States aren't supposed to allow to be used to pay debts.
But then the Constitution is a living document that can only be interpreted by what's happening today, not strictly as written. (At least that's what they tell me.)
And you conservatives have come a long way, baby, from what you used to stand for. Now you'll stand for anything.
A lot of people write, and think, silly things because they don't really understand what they are talking about. Article One, Section 10, of the Constitution prohibits the States from making anything but gold and silver acceptable for payment for debts. Well and good. However, it is the federal government which declares our money to be legal tender for all debts.
Take a dollar bill out of your wallet. Turn it so Washington is face up. Look at the upper left hand corner. In fine print, it says, "This note is legal tender for all debts, public and private." 'Nuff said.