The aim of this paper is to discuss the problem of the underdetermination of metaphysics by physics. It is, in fact, possible to show that different metaphysical options are available to interpret the same physical theory. However, physics cannot help to decide which is the most correct one. In particular, in this paper I will focus on the case study of quantum field theory (and its algebraic formulation). I will show that there are at least two metaphysical theories that can be considered as legitimate interpretations of the theory. Yet, no choice can be made between them by only physical means, and we need to appeal to non-empirical criteria. I will show why such criteria are not eventually compelling from a naturalistic perspective. I will conclude the paper with a proposal of a pragmatic solution to this open problem.
