I explain modern banking, illustrating how the clearing process allows banks to create "money". I examine interest and the fundamental mathematical contradiction of banking: creating money as a debt-of-itself on a schedule, and then encouraging us to salt it away indefinitely as savings or other forms of loaning existing money. The result is that the original borrower can't earn it debt-free to pay off the loan that created it. Therefore the original principal will be paid off with the principal of some other loan creating a Perpetual Debt.
I can now say, from several years of experience, that this simple argument is vigorously ignored by economists.