I am just back from a very nice event around Paul Baum’s seventies, which took place in Warsaw last Monday, thanks in particular to Piotr Hajac. I have known Paul since the summer of 1980 when we first met in Kingston. I really had, when I first met him, the impression of meeting l'”Homologie en personne”. The more I got to know him through our very long collaboration, the better I enjoyed his clarity of mind and his relentless quest for simplicity and beauty. In many ways he succeeds in doing something very difficult, which Grothendieck advised in “Récoltes et Semailles”, namely to keep “une innocence enfantine” in front of mathematics.
The dinner on monday night was comparable in intensity to the memorable one in Martin Walter’s place, in Boulder, for Paul’s sixties when the team Paul Baum—Raoul Bott forced Martin to search (again and again) his cellar for more bottles of wine to keep up with their drinking ability!.
Raoul Bott died in December 2005. Not long before, Paul went all the way to California to visit him and they talked together for an entire day. This type of faithfulness in friendship and understanding of what really matters, is an attitude towards life which Paul has and which I truly admire.