I have a line of thought that strict naturalism (in the most extreme case, the belief that only particle physics is an accurate description of reality) is self-defeating. I say this because notions like intentionality, reference and semantic truth cannot be expressed in the language of particle physics. Without appealing to intentionality, it's unclear what it would even mean to say claims about particle physics are true and other claims are false. Therefore, in addition to natural facts, there must be something like fregean senses or epistemic norms. Is this considered a serious line of argument in philosophy today?

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    Well, I'd say that intentionality, reference, and semantic truth can indeed be expressed in the language of particle physics. You just have to work really hard. It's as difficult as expressing a chair in the language of particle physics; in theory possible, but in practice it's a very long formula.
    – causative
    Commented May 2, 2023 at 22:44
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    Perhaps I wasn't clear enough. Intentionality supervenes on what is happening in a human brain - and what is happening in the brain is in principle describable in terms of the subatomic particles, though this would be very difficult. In principle, therefore, it is possible to talk about intention using particle physics. "I intend to eat that sandwich" corresponds to a particular situation of particles in my brain, which particle physics is capable of describing.
    – causative
    Commented May 2, 2023 at 23:38
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    @NoahMancino If you claim that intentionality... cannot be expressed in the language of particle physics, you should explain why - after defining all those words more precisely. "Without intentionality..." is not an explanation, because it seems circular. It seems to assume the existence of intentionality as a pre-requisite for claims in particle physics, and that existence is not obvious. It's as if you were saying "intentionality exists therefore naturalism is false", but you have to show that intentionality cannot be explained in naturalism.
    – Frank
    Commented May 2, 2023 at 23:45
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    In a sense I agree that meaning is determined by use, but I would like to say meaning is also determined in some sense by how language ought to be used. If this is not the case, it seems unintelligible that words have meanings at all. How are we to distinguish between good uses of language (paradigmatically, correct claims) from bad uses (paradigmatically, false claims or ungrammatical ramblings)? To answer my own original question, I found at least two widely read authors who agree with me: Robert Brandom and John Searle Commented May 3, 2023 at 0:57
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    There are plenty of opponents to the full-blown concept of reductionism. In fact I would say that scientific reductionism is a much less popular position in the philosophy of science than it was 50 years ago. Some of the objections are due to issues over consciousness and intentionality. Try David Chalmers, "The Conscious Mind", Thomas Nagel, "Mind and Cosmos", Alvin Plantinga, "Where the Conflict Really Lies".
    – Bumble
    Commented May 3, 2023 at 2:17

4 Answers 4


You seem to be attacking a common strawman of naturalism

What you presented as naturalism (or "strict" naturalism) may be self-defeating, but this is not what naturalism is, according to naturalists. Whether something that no-one believes is self-defeating is generally irrelevant.

Naturalism is "the idea or belief that only natural laws and forces (as opposed to supernatural ones) operate in the universe".

This is a dismissal of the supernatural (generally due to a lack of supporting evidence).

It doesn't imply that everything needs to be able to "be expressed in the language of particle physics", and the only people I've ever heard say something similar are people (often theists) who object to naturalism.

For one thing, naturalists typically accept mainstream scientific knowledge from every field, not just the one branch of one field of science that is particle physics. All of that may ultimately boil down to the movement of physics particles, but one could've been a naturalist before we even knew about atoms. The essence of naturalism is not particle physics, it's the natural world. It's just that the best model of the natural world says that every real-world object is made up of such particles.

Beyond that, there seems to be some confusion or disagreement in the question about what it means for something to exist (according to naturalism), and what naturalism entails.

Naturalism isn't incompatible with semantic truth or epistemic norms, because those things don't directly exist in reality, therefore naturalism doesn't make any claim about them.

Regarding intentionality, naturalism holds that minds are reducible to natural processes

If you claim that there's some element of the brain/mind that exists outside the natural world, you obviously reject naturalism, and this wouldn't be a counter-argument as much as a claim that naturalism is false.

It is certainly one common view that there is a mind separate from the brain and outside the natural world. Many theistic beliefs (arguably) rely on it. But the fact that people believe something doesn't mean that it's true.

It's true that we don't yet exactly know how consciousness comes about from natural processes, but not knowing something doesn't mean the supernatural exists.

"Without appealing to intentionality, it's unclear what it would even mean to say claims about particle physics are true and other claims are false."

A claim is true if it matches objective reality. A claim is false if it doesn't match objective reality.

We can evaluate the truth value of a claim (to the extent that we can know truth) through e.g. observation and science.

I don't see the need to appeal to intentionality here.

Semantic truth does not (directly) exist in reality

Let's say I state that the Moon exists.

The statement itself may exist as thoughts (i.e. electric signals between neurons), as bits in a computer, as soundwaves, etc.

What I made a statement about (i.e. the Moon) may exist or not exist.

The semantic truth of the statement is only a derivation of the existence of the statement and the existence of the applicable parts of reality. The statement is true if and only if it matches reality.

Epistemic norms do not (directly) exist in reality.

Epistemic norms are a set of principles for how we evaluate what is and isn't true.

We determined these principles by observing the world, and seeing which principles would correspond most closely and be most consistent with what we observe.

These principles exist as nothing more than thoughts (or as bits in a computer, as soundwaves, etc.). These principles do not exist independently. We came up with them, to allow us to serve some goal (e.g. to tell us what's true, or to allow us to effectively navigate reality).

The principles may be effective at achieving that goal, or it may be ineffective. Similar to semantic truth, the effectiveness wouldn't exist directly, but rather would be a derivation of things that exist (i.e. the principle as a thought, along with real-world objects or laws that the principle may correspond to).

If I say you should believe whatever you see (not a good epistemic norm), what could exist is this principle as a thought, the objects you see and mental processes that correspond to your sense of sight. If you follow this principle, you'd believe in the existence of some things that exist and some things that don't exist. The principle itself doesn't exist outside of that.

  • Seems to reduce to: "Truth does not exist, in reality." (Oops, ignore that extra comma...) Very nondual.
    – Scott Rowe
    Commented May 3, 2023 at 10:40
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    The claim that non material things do not exist is not supported by evidence. It is an assertion of dogma or ideology and thus not naturalistally valid. Science is based on indirect realism and worlds 2 and 3 of Popper and Frege are as well supported by their utility and test ability as matter (world 1) so a consistent naturalist should be a triplest. Also science needs emergence, and processes, and neither are reducible.
    – Dcleve
    Commented May 3, 2023 at 14:51
  • @Dcleve Both the non-existence and the existence of non-material things is not well-supported by evidence. (And claims of non-material things, e.g. religion, are often explicitly dogmatic, so it's rather ironic ... and exhausting ... to have people claim skepticism of that is dogma.) So, the question is whether it's more reasonable to believe that something exists until it's disproven, or to believe something doesn't exist until it's proven (if it can even be proven). Naturalism says the former. See also: Russell's teapot.
    – NotThatGuy
    Commented May 3, 2023 at 15:16
  • @Dcleve I'm not really sure which part of my answer you believe you're responding to. It seems like you basically just want to object to naturalism in general. But I wasn't arguing for naturalism in general, I was addressing the specific objections raised in the question, so your comment doesn't seem all that relevant to my answer.
    – NotThatGuy
    Commented May 3, 2023 at 15:21
  • @NotThatGuy Read Two Dogmas of empiricism, I think it’s section 9. Quine notes that the evidence and utility based inference to the reality of math and ideas is equally strong as the inference to the reality of matter. Quine does not make the argument, but it is an easy extension to apply it to consciousness, where experience is MORE supported than either ideas or matter. This gets one immediately to 3 world triplism.
    – Dcleve
    Commented May 3, 2023 at 15:22

Naturalism doesn’t say that everything must be described using particle physics but rather that the cause of everything that exists is natural. Concepts and ideas only exist in an immaterial sense but even they can only be thought about and hence caused by a brain which has material causes.

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    Right. It's like my favorite example of levels: this comment I am writing on this computer is not determined by the computer, yet the computer is fully deterministic. Nothing about transistors had anything to do with choosing these words.
    – Scott Rowe
    Commented May 3, 2023 at 10:32
  • The causal closure of physics is not supported by physics, which as a science is intrinsically open. This is Hempel’s Dilemma for physicalists. That ideas are causal is readily verified by every one of us every day. The dogma of physicalism is contrary to science. It also violates naturalism by banning the indirect inference to reality for any non material hypotheses. Equating physicalism to naturalism is thoroughly refuted by test.
    – Dcleve
    Commented May 3, 2023 at 15:49
  • Do you have reference for your claim? It sounds plausible, but is not how I usually see 'naturalism' defined.
    – user65758
    Commented May 3, 2023 at 16:18
  • I found someone who agrees with you, the psychologist Thomas Hardy Leahey say it's "the thesis that no supernatural or non-natural causes are at work at nature". But I don't think it's a universal definition, so your answer should reflect that
    – user65758
    Commented May 3, 2023 at 16:50

Yes, this is an argument against extreme naturalism and it’s validity is a mainstream view.

The extreme reductionist thesis you describe is explicitly "scientism", as it holds that all knowledge reduces to science, and explicitly to physics. The prevailing view among almost all philosophers is that science cannot justify itself, it needs to be justified by the philosophic subfields of logic and epistemology, as a minimum. And physics cannot be done without mathematics, which also is prior to science.

If other knowledges precede physics, and are more fundamental, then yes, it is incoherent to claim that everything reduces to physics, and scientism is therefore incoherent.

As a broader phenomenon, even within science the consensus view today is that other sciences do not reduce to physics. This has been a growing into a consensus, as the recognition of the failure of a program of pure reductionism became a majority view in the 1990s in philosophy of science, and that majority has expanded since. The explanations for the failure of reductionism point to the irrelevance/orthogonality of higher order structures to any aspect of a substrate. See SEP's Scientific Reduction article, particularly section 5.

The poster child for the failure of reductionism is explicit in the term multiple realizability -- a function or behavior can be demonstrated with nearly infinite different KINDS of substrates, hence that function or behavior can never be reduced to features of the substrates.

The need for emergence to explain the appearance of entirely new scientific phenomenon as complexity increases, plus the utility of holistic models to explain phenomena that are incomprehensible to reductionism, have further led science to embrace a pluralism of fundamental sciences, and a pluralism of methodologies to investigate them.

And the abandonment of scientism extends the pluralism of knowledge to non-science activates. This is how far your first objection goes.

Your second objection, intentionality, is a less universally accepted problem even for reductionism. The majority view in philosophy even among naturalists agrees with your view that reductionism can never explain or characterize consciousness. But a stubborn minority of naturalists still argue for promissory reductionism -- that maybe someday consciousness could be reduced, even if it is not possible today. Note however, that contra to this minority, the SEP article on reduction explicitly named the inability to reduce consciousness as one of the prime examples of the intrinsic limits of reductionism. So -- you have a majority view in philosophy supporting this point, but not yet a consensus, due to the stubbornness of the counterarguers.

Naturalism, however, is a flexible term, with multiple variants of meaning and usage. One can be a committed naturalist, and still accept all of the above as true. So "refuting naturalism" and "refuting absolute reductive naturalism" are very different things, with the first much harder to do than the second.

  • The claim that "everything can be reduced to Particle Physics" cannot be reduced to Particle Physics. So it is self-defeating. Cool. So, is something more fundamental than Mathematics? Or is that the last turtle?
    – Scott Rowe
    Commented May 3, 2023 at 10:35
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    Most things are reducible, but what epistemology is arriving at is the realization that not ALL things are reducible, hence we need multiple epistemic heuristics. Emergence, wholism, and process science (not everything is a thing) are also needed to understand our universe. A pluralism of heuristics means no, neither math nor logic can be an alternate “final turtle”, the turtle series is only part of the story.
    – Dcleve
    Commented May 3, 2023 at 14:33
  • I'm having trouble parsing your first sentence. Is there a word missing or are they in the wrong order?
    – Barmar
    Commented May 3, 2023 at 14:38
  • @Barmar thanks. Edited.
    – Dcleve
    Commented May 3, 2023 at 14:54
  • "Only realize, there is no turtle" I guess?
    – Scott Rowe
    Commented May 3, 2023 at 19:06

Yes, this view that only atoms exist is mainstream, and it is wrong for many reasons.

You are correct that intentional phenomenological structures form wholes that cannot be reduced to atoms. As far as this being fringe / mainstream, it depends on what area of philosophy you deal with. In phenomenology it is mainstream, and in anglo-american analytic philosophy it is fringe.

Very few people realize that the concept of atoms is contradictory. A-tom comes from the greek for "a" (negation) - "tome" (to cut). An atom is that which cannot further be dissected. Yet, this supposedly indivisible unit is made up of neutrons, protons and quarks.

Atoms are supposed to be independent little balls that would exist if the rest of the universe did not exist, and then they say that they are actually wave functions, and those wave functions interact with other wave functions. So atoms are not really independent balls, they are non-physical wave functions.

Therefore, and atom is an indivisible divisible thing, and it is matter that is not actually matter, which is nonsense. Atoms as little bouncy balls do not exist.

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    "the concept of atoms is contradictory. A-tom comes from the greek..." - uhh... the word we use for a concept is largely unrelated from whether or not the underlying concept is contradictory. That point would fall apart if we use "flarglebargle" to refer to what "atom" refers to now. "Atoms are supposed to be ..., and then they say that they are actually ..." - I'd suggest taking any concerns you have over the supposed contradictions in physics, and directing those to physicists. In any case, we model reality as accurately as we can. If you have better physics models, proposals are welcome.
    – NotThatGuy
    Commented May 3, 2023 at 15:11
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    I think pretending that naturalism was based on an oxymoronic concept and therefore nonsense is building a strawman and a weak one at that. Show me a contemporary naturalistic philosopher who is ontologically bound to having atoms in this literal sense (or even at all) as the ultimate building blocks of reality.
    – Philip Klöcking
    Commented May 3, 2023 at 15:31
  • This answer seems to conflate the philosophical concept of atoms with the objects chemists have decided to call atoms.
    – Sandejo
    Commented May 3, 2023 at 22:57
  • @PhilipKlöcking I think Ladyman and Ross have something close to the extreme view I mentioned, but throwing that out there is a mistake. I agree that what I called the "strict naturalist" view is not what most philosophers that would call themselves naturalists believe (that's why I called it an "extreme" form). I do think many naturalists would be willing to call intentionality and norms convenient fictions. Others would say they are real but reducible to natural which doesn't sound right to me but that is a more complicated matter Commented May 4, 2023 at 16:38

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