  The present discussion concerning certain fundamental physical theories (such
as string theory and multiverse cosmology) has reopened the demarcation problem
between science and non-science. While parts of the physics community see the
situation as a beginning epistemic shift in what defines science, others deny
that the traditional criterion of empirical testability can or should be
changed. As demonstrated by the history of physics, it is not the first time
that drastic revisions of theory assessment have been proposed. Although
historical reflection has little to offer modern physicists in a technical
sense, it does offer a broader and more nuanced perspective on the present
debate. This paper suggests that history of science is of some indirect value
to modern physicists and philosophers dealing with string theory, multiverse
scenarios, and related theoretical ideas.
