The Road To Serfdom...The Price Of Safety

In the past when borrowers couldn't pay their debts with interest they became the serfs of money lenders. That's why usury was often forbidden. Usury was the road to serfdom. Most people have forgotten about that. Nowadays most money is debt. Money is loaned into existence and must be repaid with interest. But if the interest rate is 5% and there is € 100 in existence then € 105 must be returned. So where does the extra € 5 come from?