Facebook and other social networking sites are bringing together spheres that used to be separate. People no longer have private and public lives; the line between the two is becoming blurred.

A Facebook message will never be able to replace face-to-face interaction.

It's completely legitimate for a company to continue striving for growth and higher profits. But business activities have to be conducted in a sustainable manner.

For more than 3,000 years, China and India accounted for half of the world's economic output. But then the Industrial Revolution gave North America and Europe 150 golden years. If you take the long-term perspective, our economic dominance has been more of an exception than the rule.

Enormous forces are affecting the world, and we can't possibly overestimate their importance. These include demographic developments, climate change, digitalization and the rise of Asia. And then there's the most important one: the end of a life lived on credit. We must finally free ourselves from debt.

The problem with our Blackberry society is that hardly anyone has time anymore to have an unhurried discussion about the long-term developments that will change our lives.

Germany's population is getting older and older and smaller and smaller. To be able to finance our welfare system over the long term, we need more women in the workforce, more children and more immigrants.