The most memorable moments of my student days were the philosophical debates at research seminars with Georg Henrik von Wright, Jaakko Hintikka, Erik Stenius and many other talented individuals. I discovered that a philosophical understanding of matters can be reached by analysing a challenging problem or by questioning the conventional wisdom on basic concepts. It is difficult to describe all that this way of thinking entails, but it is clear when one encounters it. These moments had an enduring impact on me. I still greatly enjoy philosophical and logical argumentation, which is often intense and passionate. Argumentation may also lead to strong dichotomies.

The series of research seminars on theoretical philosophy is still going strong, and I truly enjoy philosophical debates with my colleagues. I receive similar enjoyment from my interaction with students and from training them for the “philosophical game.” This might partly explain why I have written most of my books with co-authors. I will give one example: writing a book on logic and games together with Allen Man and Merlijn Sevenster was a rewarding and unique experience. It was a real challenge to combine the views of a mathematician (Allen), a private sector computer scientist (Merlijn) and a philosopher on logic. I argued a lot, but I also learned a great deal!