Concerning Metaphysical and Methodological Naturalism

Concerning Metaphysical and Methodological Naturalism May 1, 2020

I was having a Tippling Philosophers’ debate concerning naturalism elsewhere and my friend stated this, which is worthy of debate and unpicking:

Naturalism is a picture of the whole of reality that cannot, according to its own intrinsic premises, address the being of the whole; it is a metaphysics of the rejection of metaphysics, a transcendental certainty of the impossibility of transcendent truth, and so requires an act of pure credence logically immune to any verification…. Thus naturalism must forever remain a pure assertion, a pure conviction, a confession of blind assurance in an inaccessible beyond; and that beyond, more paradoxically still, is the beyond of no beyond.

Let me set out my position concerning naturalism.

A thought experiment that I always find useful is imagining a disembodied mind at birth, if you will. Can you see that mind ever taking in more knowledge without any sensory input whatsoever? Can it access rational or non-empirical knowledge without recourse to any senses at all? And are rational sources of knowledge actually found within neural networks?

As a naturalist, and this is a pretty important point, I believe that the mind is supervenient on the physical matter of my brain and body. So at this source level, with the mind being at worst reflective of the physical brain, but certainly dependent on it, we have an issue for rationalism. Intuitive feelings or claims are still resultant from neurons firing and physical substrates and interactions within the body and brain. How does this affect the debate? If rationalism is the result of biological evolution and neural networks, what does this say about rationalism? Does it, in some manner, now become a sort of empiricism, or just because the innateness is sourced in biological systems, can we not still define something as rationalist?

AJ Ayers said of rationalism:

There can be no a priori knowledge of reality. For … the truths of pure reason, the propositions which we know to be valid independently of all experience, are so only in virtue of their lack of factual content … [By contrast] empirical propositions are one and all hypotheses which may be confirmed or discredited in actual sense experience. [Ayer 1952, pp. 86; 93–94]

What is intuition? How can it support a warranted belief? “Grasping” or “seeing” things is simply not good enough, arguably, in establishing epistemic warrant, and some will also claim (see David Eagleman’s Incognito for some interesting examples of intuition) that these intuitions are often actually previously embedded, nonconsciously experienced, phenomena. Knowledge, according to pragmatists, is only knowledge when it is reliable, and how can you test intuition without recourse to the external world in validating its reliability? As the SEP states:

What accounts for the reliability of our intuitions regarding the external world? Is our intuition of a particular true proposition the outcome of some causal interaction between ourselves and some aspect of the world? What aspect? What is the nature of this causal interaction? That the number three is prime does not appear to cause anything, let alone our intuition that it is prime.

It is true that we can never be certain about the external world. We could be living in The Matrix – there is always some non-zero element of doubt in any proposition. In a sense, that is the nature of empiricism: probabilities. But all reasoning is grounded using the Munchausen Trilemma, either in:

  • infinite regress
  • circular reasoning
  • an axiom

And, some might say, the soundest of the three is the axiom, as self-evident truth (though some don’t have a problem with circularity in principle). If you can’t give derivative reasons as to why something is true (i.e., that I am not in The Matrix), and can’t rely on empirical data, then where does this leave us? Perhaps we have to admit that there is no justifiable reason as to why we are not in The Matrix. However, this might be a neutral claim, since you could say that there is no justifiable reason as to why we are.

Certainly, self-evident truths are something that play into rationalist hands. Merely just understanding what such a claim says is enough for us to think it is true.

The idea that we have innate knowledge is, to me, problematic, given the disembodied mind hypothesis above. Knowledge flows out incrementally from brain development that goes hand in hand with knowledge acquisition. We learn. We are always learning, and this learning is done through taking things in from the outside world into our senses.

Methodological Naturalism -> Metaphysical Naturalism

Another friend in the initial debate in question here stated, as an adherent of metaphysical naturalism (MaN), which is here “the former”, talks of how methodological naturalism supports the metaphysical variety:

My case is that the latter so strongly demonstrates the truth of the former, there is no practical difference

Methodological Naturalism (MN), as a methodology of science, assumes that natural phenomena are all that we can use to do science, to work out the natural world around us. Why? Well, this is because positing anything else is, by definition, unobservable and untestable. As a result, such claims become mere assertion along the lines of “making **** up”. By this, I mean that if you come up with some causal explanation as to why something happens so, and it is supernatural, there is no way of being able to evaluate how reliable that claim is, and it becomes no more probable or improbable than me pulling an idea out of my arse and offering that.

This does not invalidate such a claim a priori. However, if naturalism has an explanation which is equally good in scope and power, then Ockham’s Razor would set preference for the simplest explanation.

Here are a few good reasons that MN is good:  testability, the use of laws in explanations, fruitfulness, the promotion of agreement and cooperation, and the avoidance of blocked inquiry. Blocked enquiry is important because what using methodological supernaturalism (MS) does is prevent further enquiry from taking place. It’s God of the Gaps, and stops further enquiry.

As Richard Carrier states:

The cause of lightning was once thought to be God’s wrath, but turned out to be the unintelligent outcome of mindless natural forces. We once thought an intelligent being must have arranged and maintained the amazingly ordered motions of the solar system, but now we know it’s all the inevitable outcome of mindless natural forces. Disease was once thought to be the mischief of supernatural demons, but now we know that tiny, unintelligent organisms are the cause, which reproduce and infect us according to mindless natural forces. In case after case, without exception, the trend has been to find that purely natural causes underlie any phenomena. Not once has the cause of anything turned out to really be God’s wrath or intelligent meddling, or demonic mischief, or anything supernatural at all. The collective weight of these observations is enormous: supernaturalism has been tested at least a million times and has always lost; naturalism has been tested at least a million times and has always won. A horse that runs a million races and never loses is about to run yet another race with a horse that has lost every single one of the million races it has run. Which horse should we bet on? The answer is obvious.

Blind conviction?

…naturalism must forever remain a pure assertion, a pure conviction, a confession of blind assurance…

Except, it is based on inductive reasoning. It has shown itself to be pragmatically useful and to work. The whole of science and technology is automatically dependent on it.

So, methodologically speaking, it is pragmatically useful and inductively evidenced to make the assumption or conclusion of naturalism. It’s not a blind conviction, but a conviction based on previous experience and evidence. But this doesn’t mean that supernaturalism can’t play some part, that metaphysical naturalism must follow, would be something one could claim. We shouldn’t shut the door entirely.

No, it’s not a Cartesian case of it being indubitably so – nothing but the cogito ergo sum does this. But what would the world look like if supernaturalism entailed? Well, we could test supernaturalism if it in any way causally interacted with our natural world, as this paper shows.

But my initial interlocutor is perhaps not thinking so much in terms of supernatural activity (a la God etc.) but in terms of meaning and metaphysics in general. Remember:

…a transcendental certainty of the impossibility of transcendent truth, and so requires an act of pure credence logically immune to any verification…

Of course, his position is…logically immune to verification as well. And empirically, too. Is this a possibiliter ergo probabiliter argument? It is conceptually possible, therefore it is probable. It could be true, so it probably is true?

I would really need an explanation of exactly what he means here. This could become a whole argument about truth theories. I prefer a whole set of theories – ideally the correspondence theory of truth, but you can never know (but this depends on epistemological theories and how we define “know”) whether a proposition is actually true or not. So we get on to pragmatic and coherence theories, amongst others. I can’t know I am not in The Matrix. Thus, I cannot know a truth proposition actually corresponds to reality and is therefore true. So I use probability, to the best of my abilities, which involves seeing how coherent claims are with other networks of perceived truth, and seeing how well they actually work, pragmatically speaking.

Does this preclude a transcendent truth? What does this really mean? This is perhaps also linked to conceptual nominalism (over which I am debating the same person in many other threads, so I think this is basically a debate about that), such that, without some aether of platonic abstracts, we can’t have ideas or layers of, I don’t know, meaning or metaphysics.

With conceptual nominalism (see my posts on Poetic Naturalism), I proffer that we conceptually construct these things, these networks, as individuals and societies. I’ll have to pursue this further with him to carry on the exposition here, but this should lay some of the groundwork down.


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