The person states:
Yes, this is good argument in support of the complete abolishment of money.
My reply is this:
Your conclusion is a non-sequitur.
The money is the convention. The money is the IOU. A promise made & unfulfilled we call a debt. The loan appears on someone's ledger (denominated in something), after a good or service has been taken by the debtor (the one who makes the promise). By denominating it in money (in this case, a Gov's unit of account), rather than in a commodity or a particular favor, we overcome the limitations of barter in the narrow & broader society/economy. Someone's promise is money, but his promise (his IOU) is money of a lower hierarchy. The Government's unit of account becomes the universally accepted unit of account within the territory which it governs because everyone owes financial obligations to the state, extinguishable only in Gov currency. And the Government's money things (banknotes, coins, reserves, securities) sit at the top of that hierarchy.