Are the laws of physics brute facts or metaphysical necessities?

Question

Definitions

• Brute fact: In contemporary philosophy, a brute fact is a fact that cannot be explained in terms of a deeper, more "fundamental" fact. There are two main ways to explain something: say what "brought it about", or describe it at a more "fundamental" level. For example, a cat displayed on a computer screen can be explained, more "fundamentally", in terms of certain voltages in bits of metal in the screen, which in turn can be explained, more "fundamentally", in terms of certain subatomic particles moving in a certain manner. If one were to keep explaining the world in this way and reach a point at which no more "deeper" explanations can be given, then one would have found some facts which are brute or inexplicable, in the sense that we cannot give them an ontological explanation. As it might be put, there may exist some things that just are. To reject the existence of brute facts is to think that everything can be explained ("Everything can be explained" is sometimes called the principle of sufficient reason).
• Metaphysical necessity: In philosophy, metaphysical necessity, sometimes called broad logical necessity, is one of many different kinds of necessity, which sits between logical necessity and nomological (or physical) necessity, in the sense that logical necessity entails metaphysical necessity, but not vice versa, and metaphysical necessity entails physical necessity, but not vice versa. A proposition is said to be necessary if it could not have failed to be the case. Nomological necessity is necessity according to the laws of physics and logical necessity is necessity according to the laws of logic, while metaphysical necessities are necessary in the sense that the world could not possibly have been otherwise. What facts are metaphysically necessary, and on what basis we might view certain facts as metaphysically but not logically necessary are subjects of substantial discussion in contemporary philosophy.

In the context of the philosophy of physics and metaphysics, what status do the laws of physics hold? Are they considered brute facts (lacking further explanation) or metaphysically necessary facts (somehow self-explanatory)? Or are there philosophers who propose alternative views beyond these two options? If there are multiple views on this, what would be an overview of them and the arguments presented for each one?

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Addendum - Other Types of Necessity (source)

Metaphysical necessity is contrasted with other types of necessity. For example, the philosophers of religion John Hick and William L. Rowe distinguished the following three:

1. factual necessity (existential necessity): a factually necessary being is not causally dependent on any other being, while any other being is causally dependent on it.
2. causal necessity (subsumed by Hick under the former type): a causally necessary being is such that it is logically impossible for it to be causally dependent on any other being, and it is logically impossible for any other being to be causally independent of it.
3. logical necessity: a logically necessary being is a being whose non-existence is a logical impossibility, and which therefore exists either timeless or eternally in all possible worlds.

Answer 1

The universe is the way it is. There is no scientific theory explaining why it is the way it is.

1. Science observes phenomena and attempts to explain these phenomena by reducing them to general laws of nature. But science does not explain why just these laws, e.g., why the fundamental constants like the speed of light, the charge of the electron, the Planck constant etc. have just the actual values.

   You may call that accepting the laws of physics as a brute fact.

2. Not everyone is content with this state of affairs. Hence different people have invented a series of speculations about possible reasons behind these brute facts: The anthropic principle, the multiverse concept, different kinds of religious speculation about a creator, etc.

   Some of these speculations are interesting and broaden the scope of our thinking. But neither of them derives from a more basic scientific cosmology.

3. Metaphysical necessity seems to be a controversial concept. Sometimes it is described as

   If something could not have been otherwise, no matter how the world had turned out, that thing is metaphysically necessary.

   A paraphrase like this does not help when asking about the world as a whole.

   Hence at this point the OP’s question goes beyond what philosophy of nature is able to achieve.

Answer 2

Analytic philosophy has gone in a bit of a circle about this. At one point, R. M. Hare (a Christian of some sort, more prominently known as a moral philosopher) indirectly resurrected a word that seemingly shows up in the works of Aquinas (a Catholic Christian), i.e. "supervenience,"^R and a metaphysical explanation tended to be one involving statements of supervenience relations. This didn't get analytic philosophy as far as it wished, however, so the thematique underscoring supervenience-talk mutated into a new emphasis on another word, "grounding."

So it was supposed to be that metaphysical grounding is distinct from causal grounding (and either, perhaps, from normative grounding). However, it was easy to ignite new theories of essentialism, using grounding-talk as a spark (see e.g. Wallner[16]). Essentialism is not much different from Aristotle's conceptions of formal and material causality modulo his theories of subsistence and hylomorphism, though. So we have not got the most stable distinction between metaphysical and physical explanation (not least because we have not much in the way of stable definitions of the very words "metaphysical" and "physical"), nor then of grounding vs. causation.

From a Kantian point of view, even a statement of causality, especially in general, carries metaphysical import. Other things being equal, we don't empirically perceive universal connections between event-types. The assertion, "There are causes and effects" (or, "Every event has a cause") has a metaphysical flavor to it.

On the other hand, would we want to ask what causes the laws of physics to be as they are? If those laws are causal laws, we would be asking after the cause of causality, which is a murky issue. Yet then we might want to be able to ask, "What grounds the laws of physics?" (As Stephen Hawking asked, what "breathes fire" into the equations of these laws?) Alternatively, we could just go ahead and declare grounding to be second-order causality, or meta-causality, which would satisfy the seemingly obvious definition of the word "metaphysical" (even if it was lexical happenstance that Aristotle's meta-causal musings were put down in a text with the relevant title).

At any rate, the "laws of physics" in physics proper are much more intricate things than just universal conditionals like, "If there are ever A's, those A's are always followed by B's," and there is an enormous amount of mathematical analysis that goes into relating laws on different levels, of trying to unite them in one metaphysically stable pattern. There is the matter of symmetry and symmetry-breaking, for example; or then the theory of structural realism. So an "explanation" of where specific laws of physics "come from" could be: they come from an ambient pattern, e.g. maybe from amplituhedra (or whatever). And these "come from" a "mathematical universe unto itself," which comes from "logical/modal space" (or: the ensemble of logically possible mathematical universes is "grounded in" the space of logical possibility, so as to establish a peculiar logicism about mathematics). (Or, if we're not fanatical foundationalists, we might think that logic and mathematics reciprocally ground each other, or that logic is itself divisible into levels such that some levels of logic ground others, etc.)

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^RHare arguably popularized the new use of this term, but he disavowed being the genuine originator of the trend; see his [84], where he says, "I do not know who first turned the word 'supervenient' to its new use which has become current in philosophy. I am certain only that I did not, but that it was already familiar when I was writing The Language of Morals."

Answer 3

This question makes two invalid framing assumptions, which lead to a misleading statement of the question being asked.

Mistake 1, science laws are not unbreakable "laws" they are regularities, and are broken. See this paper explaining how all laws in physics are broken: https://www.pnas.org/doi/10.1073/pnas.93.25.14256

Mistake 2, global reductionism has failed, and it is not true that everything reduces to physics. See SEP section 5: https://plato.stanford.edu/entries/scientific-reduction/

Rephrasing to avoid these errors, your question is: "are any aspects of our universe metaphysically necessary, either within or outside science?"

Since scientific laws are breakable, they are by definition not "necessary", so your original phrasing is answered in the negative.

Rather than laws or any other science properties being "necessary" science itself is committed to science being contingent, and the discoveries of science to be "brute facts" that could have been otherwise.

So -- science cannot be the subject area where methodological necessity might lie. The alternative that analytic philosophers sometimes invoke, as to what other than science might provide necessity in this world, is mathematics or logic. Here is an example paper that explores this possibility: https://philarchive.org/archive/NOLTEO#:~:text=A%20lot%20of%20philosophers%20engage,status%20of%20%E2%80%9Cmetaphysical%20necessity%E2%80%9D.

However, both mathematics and logic are infinite in possible forms: https://www.cambridge.org/core/journals/think/article/abs/guide-to-logical-pluralism-for-nonlogicians/EDFDFA1C9EB65DB71848DABD6B12D877 And what math or logic applies to a particular aspect of our world, is once again a contingent question. One might be able to derive metaphysically necessary conclusion within a specified logic and/or math system. But try to apply that conclusion to THIS world, and it becomes a contingent/brute question whether that is the right math or logic.

Answer 4

Both.

Going by your post, a brute fact would be one that has no further explanation.

Something that is metaphysically necessary can have a further explanation. For example, in a deterministic universe, and assuming that the laws are necessary, everything by extension becomes necessary. However, this does not mean that there is no explanation for where I come from, even though I now become metaphysically necessary. In this case, the further explanation would be the biological processes that created me.

However, if the laws of nature have no further cause, then they de facto become a brute fact (for this reason) and metaphysically necessary (since by definition, they are physically necessary if those are the only laws that operate).