ABSTRACT
There are some artists of whom it is said that they always return to paint the same picture over and over again. The same is often said of researchers: they always return in their work to the same theme. I have to confess that ever since my early student days, I have been intrigued by the question of how our common world, our shared reality, is created. My interest is not just professional, but personal. How am I part of this world? Where do I belong? How am I part of different communities? How is social life possible in the first place?
