The circularity isn't really a problem here, since the flow of money is a circle. Money is the token used to repay the debt, but the token is created because s

The circularity isn't really a problem here, since the flow of money is a circle. Money is the token used to repay the debt, but the token is created because someone else has gone into debt. They in turn will need to obtain money which is the debt of someone else somewhere up the chain. (Even if it's bank reserves and cash, in well functioning modern economies they're injected by the central bank monetising existing debt, usually government debt.) It's probably more strictly true to say that having money is the credit extended in the credit/debt relationship, but they're two sides of the same coin.