Ontological and methodological virtues of unification

The widespread mistrust of metaphysics-the main obstacle to the unification of physics and philosophy-is based on the myth that metaphysical claims cannot be falsified or verified, because they are supposedly true independently of empirical knowledge. This is not true of metaphysical naturalism, whose approach is to critically reflect on the theories and findings of all the empirical disciplines and abstract from them a theory about such general features of reality that no single empirical discipline can be the authority on. Causation is such a feature, since its instances include anything from planetary motions to particle interactions, chemical reactions, biological functions, and closing a door. Consequently, a general account of causation is beyond any particular empirical discipline. Metaphysical naturalism takes a meta-perspective on the results of the empirical sciences and attempts to figure out how it fits together in a coherent whole, e.g. by offering a general account of causation. General accounts of this kind are falsifiable in so far as the theories are falsifiable from which they are generalizations. The paper also discusses some fundamental metaphysical principles implicitly assumed by the sciences generally, and why they imply that unification is methodologically virtuous.