  I suggest that the current situation in quantum field theory (QFT) provides
some reason to question the universal validity of ontological reductionism. I
argue that the renormalization group flow is reversible except at fixed points,
which makes the relation between large and small distance scales quite
symmetric in QFT, opening up at least the technical possibility of a
non-reductionist approach to QFT. I suggest that some conceptual problems
encountered within QFT may potentially be mitigated by moving to an alternative
picture in which it is no longer the case that the large supervenes on the
small. Finally, I explore some specific models in which a form of
non-reductionism might be implemented, and consider the prospects for future
development of these models.
