Is materialism really an ontological position or is it an epistemic one?

Question

In this post, Is a materialist afterlife possible? , the OP asks if the concept of afterlife as accepted in Christianity (and presumably other religions) is compatible with materialism. Presumably this means a strictly materialist ontology that also includes an omnipotent God.

But this would be a strange form of materialism indeed. The way I see it, most materialists believe at least implicitly that materialism implies that nothing is possible that doesn't follow the laws of physics.

Materialist disbelief in deities, spiritual beings, souls, cartesian mental substances, etc...usually stem from the fact that such entities existence defies the known laws of physics:

• Either such entities do not follow the laws of physics, and they believe that that is impossible. Or,
• The laws of physics are so radically different from what empirical evidence has shown us that such entities are possible, an equally unlikely scenario.

Based on these two considerations, they would rather just deny the existence of deities and spiritual entities all together, as this is the most likely case given empirical evidence.

So materialism isn't really a position about the ontology of the world, but more of a statement on whether the world follows certain laws or not, and what is the source of these laws.

1. Is this reasoning correct?
2. If materialism isn't an ontological position, is it an epistemic one?

Answer 1

I think your questions cannot be answered unless you nail down what you mean by key concepts like "ontological", "epistemological", and "physics" (I know many philosophical discussions fail to do this--hence the quagmire).

(1) I use ontological roughly to mean "having to do with mind-independent...".

For the sake of simplifying this discussion, let epistemological mean mind-dependent (although if necessary, we can further refine this by limiting the dependence to a subset of the mental, such as belief-states, knowledge-states, etc.)

There is room for refinement here in specifying the nature of the dependence relationship. For example, second-order mental states are mind-dependent in some sense (they need first order mental states to exist); yet they are mind-independent in another, more relevant sense (pace Wittgenstein, a mind does not depend on the existence of other minds to exist).

In this sense of ontological, the laws of physics are ontological. They need no minds to exist, if they do exist (i.e., the universe is not lawless).

Just for illustration, think here of a Platonist who says "Laws of physics are relations between universals, and the relations themselves are universals". Don't worry that Platonism is outré, just take this as an example of the most outré way in which laws of physics can be cast as mind-independent.

On the other hand, the laws of physics "as we know them", "as projected based on the best evidence we have" etc. would denote epistemological concepts.

(2) Physics is the science of everything--or so used to say Quine in his more glib moments. Let us take him seriously for a moment (as do many philosophers). So if we perchance live in a pluralistic universe that contains more than one basic ontological category, physics has to cover all of these categories of entities. If there really are minds and abstract entities (like numbers and sets) etc. that are irreducibly distinct from tables and chairs, physics would have to cover them as well. I know this is not what Quine and like-minded philosophers want to conclude, but this is what their usage of "physics" seems to entail.

One might choose to define physics differently, but as defined above, physics is not a guide to ontology--it needs to be guided by ontology.

Anyhow, just trying to emphasize the shiftiness of contemporary philosophical terminology, and the need to "stabilize" it to reach sensible answers.

Good luck :)

Answer 2

I take materialism to be a metaphysical position with epistemological implications. It commits one to the view that physical (scientific, natural) explanations are closed, that is, that such descriptions/explanations contain no non-physical terms (or references to non-physical entities, properties, processes and so on), but that commitment is entailed by an underlying metaphysical commitment that only physical entities etc exist. Two quick points: 1) One might try to avoid "doing metaphysics" and define materialism as a kind of theory of truth (along pragmatist lines, say) but this will never be satisfactory as one will never be able to justify such a theory in the absence of a willingness to acknowledge the underlying metaphysical assumption. 2) Consider three words, "materialism," "physicalism" and "naturalism." All imply some thory of nature: that everything is matter, that everything is physical, and that everything is nature, respectively. It is reasonable to point out that the current best physical theories of what "matter" is, say, do not enjoy much consensus and are in any event very strange. But a good argument (that I take from the late E. J. Lowe) is that without some axiom of ontological unity both philosophy and science would not be possible (roughly, generalizations as such would have no foundation). So perhaps just plain "monism" is the metaphysical tendency that ought to be emphasized, versus any sort of dualism.