It is interesting that the monks discovered they needed interest to keep the system operating. We can accommodate interest provided it does not compound. In other words it is a fee for operating the monetary system. Technically it is easy to get rid of compound interest by repaying capital first and interest last or by issuing credit that buys more in the future through discounts. In other words we can fix the system by a simple accounting change. This is the way public banks should operate to be most effective. If they do this they will be able to offer better lending rates to savers by not compounding interest. e.g. a fixed 6% inflation adjusted non compounding loan over 30 years gives about the same return as a 4% compounding loan. We can also put a fixed fee on money transactions (a tobin tax) as the way to pay for the utility that money brings - and get rid of compounding. Savers should get a return on their savings and the simplest way is fixed interest. Banks should get a fee to operate the system and the simplest way is to get part of the interest. What we need to do is to get rid of interest on interest as the main method of creating money. When extra money is needed then the central bank prints it and distributes it equally to everyone in a society. We know we need to print money when the fixed interest rate goes higher than the increase in productivity improvements from invested savings or when the lack of money causes unemployment which in turn causes a reduction in overall productivity.