Structural Realism or Modal Empiricism?

Structural realism has been suggested as the best compromise in the debate on scientific realism. It proposes that we should be realist about the relational structure of the world, not its nature. However it faces an important objection, first raised by Newman against Russell: if relations are not qualified, then the position is either trivial or collapses into empiricism, but if relations are too strongly qualified, then it is no longer structural realism. A way to overcome this difficulty is to talk about modal, or nomological relations instead of purely extensional relations. I argue that this is insufficient, for then, structural realism collapses into modal empiricism. I suggest, however, that modal empiricism could be the best position in the debate on