SPIEGEL: Hans-Werner Sinn, Henrik Enderlein, do we need shared sovereign bonds, so-called "euro bonds ," to end the financial crisis?

Enderlein: By all means. Correctly construed, euro bonds are the best instrument for preventing the collapse of the euro zone.

Sinn: The opposite is true: Euro bonds would destroy the euro zone. If all countries -- regardless of their creditworthiness -- were to pay the same interest rate, the last impediments to excessive state indebtedness would fall away.

Enderlein: If we were dealing with a functioning economic environment, Mr. Sinn, your assumption would be correct. But we have a crisis, and to end it, we need to swiftly restructure the debts of Greece, Portugal and most likely Ireland, as well. We need to give these countries' creditors a reliable type of security. My suggestion would be having one euro bond for every two Greek sovereign bonds. For investors, that would mean a loss of roughly 50 percent. But, in return, they would get a security that banks could deposit as collateral, including at the central bank and for inter-bank transactions.

Sinn: In 1995, shortly before the exchange rates for the euro were fixed, the interest rates on Italian and Spanish debt were on average about 5 percentage points above Germany's. At the end of July 2011, at the height of the turbulence, the difference was only 3.4 percent -- and that at an interest-rate level that is much lower on the whole than it was at that time. These interest-rate differentials are good for the euro zone. Indeed, it was only out of fear of interest-rate premiums that the Italians finally instituted a cost-cutting program after years of disregarding the rules of the Stability and Growth Pact. Euro bonds would eliminate this disciplining effect.

Enderlein: But Mr. Sinn, you can't compare the Europe of 1995 with the one we have today. Back then, each country could pursue its own monetary policies and print money to devalue its own currency. Today, that's no longer possible, which is also why interest rates are lower.

David Fuller's view If these opposite views presented by Messrs Enderlein and Sinn, reflect an equal divide in terms of German public opinion, then the subject of Euro bonds will be extremely contentious.

I maintain that Euro bonds are an essential step towards fiscal union and the only way the euro can survive. Consequently, I am in strong agreement with Mr Enderlein.

I would welcome more feedback from subscribers, not least those living within the eurozone.