"To do science, you need commitment and passion. You need to have at least an implicit belief that nature will not behave capriciously towards us, but will remain faithful to its laws. Above all, you need to believe that there is a truth out there, and that it is worth seeking. Every scientist has his or her own “worldview” and within that worldview employs the categories he or she finds most congenial. It is this personalistic aspect of scientific research, now highlighted by many authors, that deserves to be explored. The reasons why a scientist “embraces” one worldview rather than another also deserve to be explored."