Popper showed us that we only can falsify theories, never proof their certainty with the result (as quoted over and over again by Popper): There is no absolute certainty. Does that not automatically imply that scientists have to believe in a current model/theory as long as it has not been falsified? Maybe this "belief" is proportional to the number of times this current model has been tried to falsify, but still I would say, one cannot escape the "belief" element. And this is not restricted to Popper's scheme. Kuhn's world of paradigms needs at least as much, if not more the belief in the current paradigm. So, surprisingly, although I believe (oh no!) that one motivation for scientists to work in science always has been the safety of experimental falsification or the safety of logical falsification of theoretical models respectively, none in science seems to be able to escape the element of belief at all??