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.

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.

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

Everything that individuals ever say or write can be used against them at a later point.

Debt is not intrinsically bad. But I make clear to my children that they should only borrow as much as they will be able to pay back.

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.