If the Schengen system (of border-free travel) is destroyed, Europe will be seriously endangered politically and economically. That is why we Europeans have to invest billions in Turkey, Libya, Jordan and other countries in the region as quickly as possible everybody as much as they can.

Emmanuel Macron wants a stronger Europe, just as the chancellor and I do. I was impressed that the new president climbed onto the stage in front of the Louvre to the sound of the European anthem after his election victory. That was a very powerful symbol. It is very clear: Macron is our ally.

During the centuries-long process of Reformation and Enlightenment, Christian churches had to accept some things they didn't like. Islam will have to do the same; otherwise it isn't part of Europe.

The German export successes are not the result of some sort of currency manipulation, but of the increased competitiveness of companies. The American growth model, on the other hand, is in a deep crisis.

History shows us a lot of things. It shows why the Lord's Prayer includes the supplication: "And lead us not into temptation." In my day, dissertations were still written by hand, or drummed out with a typewriter. In the past, you had to round up the literature, find the books and find the passages. Nowadays you click on Wikipedia or Google and you have everything you need. This probably makes it more difficult to resist temptation.

I can't think of many other laws we might need. For now, though, we'll be talking to German Muslims over issues of coexistence.

We know that the abilities of European Union member states are not infinite. As such, it makes little sense for us to criticize each other.All of us accepted Sweden's decision to introduce border controls too. And that is a country that was for decades the most open to immigration.