The French philosopher René Descartes (1596–1650) once lodged at Westermarkt 6. Apparently happy that the Dutch were indifferent to his musings – and that therefore he wasn’t going to be persecuted – he wrote “Everybody except me is in business and so absorbed by profit-making that I could spend my entire life here without being noticed by a soul”. However, this declaration may itself have been a subterfuge: it’s quite possible that Descartes was spying on the Dutch for the Habsburg King Philip II of Spain, a theory explored in detail in A.C. Grayling’s book, Descartes: The Life and Times of a Genius. In the event, Descartes spent twenty years in the Netherlands before accepting an invitation from Queen Christina to go to Stockholm in 1649. It was a poor choice: no sooner had he got there, than he caught pneumonia and died.