Currently, string theory represents the only advanced approach to a
unification of all interactions, including gravity. In spite of the more than
thirty years of its existence it did not make any empirically testable
predictions. And it is completely unknown which physically interpretable
principles could form the basis of string theory. At the moment, "string
theory" is no theory at all, but rather a labyrinthic structure of mathematical
procedures and intuitions which get their justification from the fact that
they, at least formally, reproduce general relativity and the standard model of
elementary particle physics as low energy approximations. However, there are
now strong indications that string theory does not only reproduce the dynamics
and symmetries of our standard model, but a plethora of different scenarios
with different low energy nomologies and symmetries. String theory seems to
describe not only our world, but an immense landscape of possible worlds. So
far, all attempts to find a selection principle which could be motivated
intratheoretically remained without success. So, recently the idea that the low
energy nomology of our world, and therefore also the observable phenomenology,
could be the result of an anthropic selection from a vast arena of
nomologically different scenarios entered string theory. Although multiverse
scenarios and anthropic selection are not only motivated by string theory, but
lead also to a possible explanation for the fine tuning of the universe, they
are concepts which transcend the framework defined by the epistemological and
methodological rules which conventionally form the basis of physics as an
empirical science.Comment: 30 pages, submitted to "Physics and Philosophy" (Online-Journal