The metaphysics of unified science

My focus in this essay is on contemporary metaphysical interpretations of the unity of the sciences. I consider the main metaphysical view regarding the relationship of the many sciences, physicalism, and propose replacement of this view with what I regard to be a superior interpretation of the unity of the sciences. In the first sections I clarify and evaluate the two main versions of physicalism, reductionism and nonreductive physicalism. Neither view is able to support a claim of unified science. I then consider a more general semantic critique of physicalism arguing that there is no way to formulate the thesis in such a way that it is neither false nor trivial. In light of these arguments, I consider how it was that physicalism was supposed to provide a metaphysics of unified science, and focus on two aspects of unity that are in need of explanation. That is, what we need is a metaphysics that can explain the stable correlations we observe between phenomena in different scientific domains, and one that can ground a monism, the idea that the sciences all describe "one scientific world" and can converge on one truth. Taking the problems with physicalism to be serious, I then outline a replacement thesis, a causal version of emergentism, which is able to ground unified science without these problems.