All the great religions include a ban on usury, the charging of unjust interest, and Islamic Banking still practices this principle today. Very worldly businesses that also practice interest-free banking include the Swedish JAK-Genossenschaftsbank, in which customers save and lend money without interest, regional currencies, or the idea of a currency with a “circulation incentive”, which is based on the Freigeld idea of businessman Silvio Gesell. In view of the unworkability of all classical financial instruments in increasingly frequent financial crises, even conservative circles are adopting unorthodox measures: in June 2014 the European Central Bank dropped its base interest rate below 0% for the first time. Will negative interest rates become part of the monetary policy toolkit?