Substance metaphysics is incompatible with the causal closure of the metaphysical realm
The present paper argues that substantialist metaphysics are in tension with the physicalist idea that the universe is causally closed. The argument is a rather specific one and proceeds through three steps. The first step consists in arguing that monistic substance metaphysics allow for the existence of entities that cannot belong to the intended first order domain. This result sensitively depends on the nature of substances as invariant entities. The second step concludes that, if further domains are to be admitted, then they are inhabited by “higher” or (systematically) “nonstandard” entities and that, in both cases if not made somehow innocuous, such entities may take part on the metaphysical construction of the world through their own distinctive properties and causal powers. However, this latter claim is in contradiction with causal closure. But closure is the principle that mainly characterizes physicalist approaches in metaphysics and as such physicalist metaphysics cannot get rid of it. Who attempted making exotic properties and causal powers innocuous usually appealed to the Supervenience Argument. Unfortunately, as the third step proves, this argument is invalid. Finally, the paper looks forward and toward alternative models for physicalist metaphysics, like processbased models.
Keywords: Metaphysics of Quantities, Abstraction Principles, Locationism.