Treaties exist so that they will be adhered to. It only serves to strengthen euroskepticism when we constantly make promises and reach agreements that we do not adhere to.

I think we will have to spend more on defense, for infrastructure, for extension of the broadband network and also for domestic security.

It is true that no member state can be required to make payments to others. But if countries want to offer voluntary assistance, as in the Greek case, this isn't only allowed, but it's also in Germany's interest. We all benefit by ensuring the stability of the euro zone.

The United States lived on borrowed money for too long, inflating its financial sector unnecessarily and neglecting its small and mid-sized industrial companies.

About three million Muslims live in the country, but we have no relationship to our diverse Muslim society, despite the fact that it's an established part of our larger society. We need to build a stronger foundation for the relationship between Muslims and the state.

The significant collapse of oil prices shows that it was previously way too high.

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.