Methodological vs Metaphysical Naturalism
Methodological vs Metaphysical Naturalism
Argument
A frequent move in atheist argumentation is to treat the operational posture of the natural sciences as if it were an ontological verdict. Scientific practice typically adopts methodological naturalism: explanations are framed in terms of regularities, measurable entities, and natural causes, because those are the kinds of explanations that yield testable predictions and replicable results.
This is a rule of method, not a claim about what ultimately exists. It is compatible, in principle, with a theistic metaphysic, since the method does not purport to describe the whole of reality, only the subset of reality accessible to controlled empirical inquiry.
By contrast, metaphysical naturalism asserts that reality is exhausted by the natural order. That is not a scientific conclusion but a philosophical thesis requiring independent justification.
Inferring metaphysical naturalism from methodological naturalism is a category mistake: it treats a self-imposed limitation of a discipline as if it were a discovery about ultimate being. Consequently, “science does not need God” does not entail “God does not exist,” any more than “microscopy does not detect meaning” entails “meaning does not exist.”
Formal Argument
P1. Methodological naturalism is a rule of scientific practice: scientific explanations are restricted to natural causes to preserve testability and intersubjective confirmation.
P2. A methodological rule of inquiry does not, by itself, entail a metaphysical conclusion about what exists.
P3. Metaphysical naturalism is the thesis that reality is exhausted by the natural/physical order.
C1. Therefore, metaphysical naturalism cannot be validly inferred from methodological naturalism alone.
P4. Some popular arguments infer “only nature exists” from the success of scientific explanations framed under methodological naturalism.
C2. Therefore, those arguments require additional premises; without them, the inference from method to ontology is invalid.
Analogy
Consider a criminal court that adopts strict evidentiary rules: only certain kinds of testimony and authenticated exhibits are admissible, because the court aims to minimize error and bias. These rules are prudent, but they do not imply that anything outside the admissible categories is unreal.
If the court excludes hearsay, it does not follow that the events described in hearsay never happened; it follows only that the court has chosen not to treat that category as legally probative. Likewise, when the sciences exclude supernatural explanations as a matter of methodological discipline, that exclusion does not constitute a metaphysical discovery that the supernatural does not exist. It constitutes a decision about what sort of explanations a particular method can responsibly adjudicate.