Suppose we used gold as money (or silver, or cowrie shells, or whatever). If someone has extra money that they don't intend to spend immediately, they won't want to bury it in their back yard when they can make a profit by lending it at interest, even if only for a single day. We would therefore expect that each person's currency holdings (that is, the amount of gold that they have stashed away or sitting in a bank vault under their name) would be negligible. But obviously, the gold has to be somewhere. The question is this: under a commodity standard, why would anyone want to own any money at all, if doing so is always a losing proposition compared to spending or lending it? And if nobody wants it, how can it be used as money?