ABSTRACT
I dedicate this chapter to David Wolsk.1 I never met David face to face. Yesterday he died. I received the news this morning by e-mail from my friend Diana in Tucson, Arizona, whom I never met either. However, I had been able to bring her and David into contact with each other not so long ago when David happened to be in Tucson and had told me so, also by e-mail. So I mentioned Diana to him and he took the initiative to look
her up. We would all meet a few weeks from now in The Netherlands-at least, that’s what we had planned. But now it will never happen. I lost a friend whose face I never saw.
