Aristotle would have only held discourse on things within his knowledge. He would have had no concept that any society would be so dumb as to rely upon the paper promises of legal fictions. People don't earn a living by trading their labor for these paper dollars. Instead people earn a living by taking advantage of the lunacy of others who accept them. Earning a living by usury or earning a living by trading labor for paper promises are equally forbidden and doing both does not cancel the fact.