[Nevermark]

They are not determined internally.

So determined non-internally if you prefer. Non-internal to reality.

My point is that is a tautological impossibility. Reality by definition is all. That is what we want to explain (or at least, zoom in on a potential form of explanation).

Reality can't depend on anything making a choice that is not a part of itself.

[staticassertion]

I think you just aren't understanding what it means to be "brute". It does not mean "caused externally", it means "the end of the explanatory chain has been reached". If you want to say that the explanatory chain has no end, great, go for it, you now have a regress problem.

There is no "choice", there is determination, there is no explanation. If you're still framing things there, then you're just denying brute facts, but you're not about to prove that brute facts aren't possible in a HN thread and you're getting the concepts of necessity, brute, and contingent mixed up along the way.

[Nevermark]

Maybe we are missing something in each other's views. Or I am.

Here I distinguish between "explanation" and "determination". Hoping that helps.

My understanding of brute facts, is they are free values in theory, but measured values in practice. And somehow we just accept experimental measurements of some things as the end of explanation.

I am arguing against the validity of less than full determination, and pointing out that does not imply endless chains of determination.

But our explanations may forever be more limited than reality, for any. number of reasons, but not because reality doesn't fully determine everything. I can see a practical acceptance of values without full explanation, if we have reason to believe we cannot probe further.

Maybe that is a level of agreement?

--

As for complete determination, without any need for infinite regress:

Unique self-consistencies are co-constraints that can fully determine things without infinite regress. There is a unique determination loop, not an endless spiral. Uniqueness avoids the inadequacies of non-unique circular reasoning. And reality itself must have this property. The only possible explanation (from our point of view) or determiner (as it actually exists), of its own properties, is itself. As a unique self-consistent form it can do that. Constrained by self-consistency and self-containment.

I am very much trying to understand the line we disagree on, interpret differently, or not.

[staticassertion]

> My understanding of brute facts, is they are free values in theory, but measured values in practice. And somehow we just accept experimental measurements of some things as the end of explanation.

What you accept as a brute fact is conditional on your world view. For most people it's going to be very little, like "the initial state of the universe" or "the constant values of the universe" etc, although the latter is not necessarily the case either.

You seem to be trying to argue that the infinite regress can be avoided, and it's where things seem to be falling apart. You're trying to leap from a simple tautology to specific metaphysical claims that do not necessarily follow, and you're just ending up with brute facts.

You're saying that all things must be explained by reality, but that's fine and consistent with the existence of brute facts. I suspect that this is at least one of the core things we are not on the same page about. Brute facts do not appeal to things outside of reality. So any argument that starts with a tautology "reality exclusively contains reality" is just not going to get you to "brute facts don't exist" because brute facts are perfectly consistent with that tautology.

Your appeal to uniqueness isn't justified either. Why must reality have that property? This is a heavy metaphysical claim that you are asserting here, it's your "brute fact" that you're trying to say isn't a brute fact.

Perhaps a simple question will help. Under your model, what determines the speed of light? I assume your only position here would be to say that it is logically necessary?

> Maybe that is a level of agreement?

We can agree that there are limits to knowledge but we definitely don't agree that all things are determined by some other thing. I don't really commit either way, personally.

[Nevermark]

> What you accept as a brute fact is conditional on your world view.

Thanks again, for your patience on this.

Ok, is there is a subjective aspect? Driven by practicality of course? A pragmatic limit to explanation searches would make sense to me. It could even be for objective reasons, such as that our universes laws somehow prevent us from gathering enough information to pin down why something is determined the way it is.

(While not denying that something did determine the property, but is just inaccessible to us as far as we can tell.)

But as a hard principle, that there are specifics that had no complete determination, they just are this way instead of that way, "because because (period)" ... that concept seems both incoherent and slippery to even process for me.

But as a pragmatic concept about the search for explanations, it would make full sense to me.

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> brute facts are perfectly consistent with that tautology.

I really seem to be having trouble with some nuance.

I think everything is fully determined, even if we may not ever achieve a full explanation of that determination. Is that consistent with brute facts?

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> You seem to be trying to argue that the infinite regress can be avoided

> You're trying to leap from a simple tautology to specific metaphysical claims

Almost. I am not trying to make the full leap, but am pointing out that reality must be fully self-determining, and that is a strong and therefore useful constraint for searching for a theory of reality.

No other situation provides such a strong requirement. And a strong unique-to-theories-of-everything constraint provides us with an axiom to start reasoning toward a theory of reality/existence.

That is a significant foothold, and not commonly pointed out.

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> Your appeal to uniqueness isn't justified either. Why must reality have that property?

Two reasons, the first is trivial. By reality I am talking about "everything". So in that trivial sense reality must be unique.

But also in terms of guidance or verification of a theory of reality. Reality has to not only explain its own structure, but its own inevitability, i.e. its existence, and without recourse to anything else.

A provably unique theory, that meets the terms of a theory of reality, would do that.

A theory of reality is going to come down to mathematical verification, in a way that local physics never can. Local physics is not so strictly determined. Local structure can reflect structure from other parts of reality it is a part of, which we have no access to yet or even ever. So we always have to perform experiments, and even mathematically derived conjectures must verified with prediction and experiment.

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> Under your model, what determines the speed of light?

Good specific.

> I assume your only position here would be to say that it is logically necessary?

Yes. The speed of light is a result of conservation constraints and local (i.e. our universe's) structure. The topology of space-time, general relativity, quantum properties of photons must all contribute. And presumably other factors we have yet to understand.

Just like all the relations, ratios and other mysteries we have already solved, regardless if we ever thought we could.

Presumably, anyone who operates with the principle of brute facts, could have named those as brute facts, before they were solved?

Likewise, the ratio of matter and anti-matter is a product of some structure and history we haven't sorted out yet. And the puzzling distribution of masses of the leptons and hadrons are determined by some structure, perhaps involving the fine structure of space-time, that we haven't worked out yet.

[staticassertion]

I think we're running across the varying forms of the Principle of Sufficient Reason, which is, again, a somewhat contentious area of philosophy.

> I think everything is fully determined, even if we may not ever achieve a full explanation of that determination. Is that consistent with brute facts?

That depends. Your statement is effectively the "Strong PSR" - every fact is preceded by another explanatory fact.

There are weaker forms of the PSR or you can reject the PSR. I believe Sean Carrol, for example, completely rejects the PSR. This is not out of laziness, it's because he considers the PSR to be an unnecessary and costly commitment with weak justification, and that our best models of physics don't require or benefit from it (my recollection).

> Yes. The speed of light is a result of conservation constraints and local (i.e. our universe's) structure. The topology of space-time, general relativity, quantum properties of photons must all contribute. And presumably other factors we have yet to understand.

This seems to be framing the speed of light as contingent on other properties of the universe, but that just pushes us back. We could just ask if the gravitational constant is a result of other facts, for example, since you have appealed to that as an explanatory factor for C.

I could ask what explains the structure of the universe. You can then say that it's logically necessary, which is basically just saying that it's brute but with a heavier burden (you'd have to show the logical primitives you use to assert that, but the outcome is the same) or brute or brute contingent, or you'd have to say there's an infinite regress.

You can keep saying "Ah but there's this property of a photon" but now you have to explain that property. Your approach seems to be to try to derive a logical necessitarian view here by appealing to a principle like "Reality exists, reality contains all things necessarily" and then to derive metaphysical constraints from that but I'm not sure that any of the metaphysical claims are well justified here.

> Presumably, anyone who operates with the principle of brute facts, could have named those as brute facts, before they were solved?

Of course. And they would have been wrong. In general, models attempt to minimize brute facts because of their cost, but all models have costs. If you want to express that the universe is unique, or non-contingent, that is a cost of your model. Strong PSR is itself a heavy metaphysical claim that will bring along its own commitments.

[Nevermark]

Brut facts. Principle of Sufficient Reason. I am getting a vocabulary bump here. I spent some time further expanding my vocabulary on related concepts on Wikipedia.

> Your statement is effectively the "Strong PSR"

I would agree with that.

But coming across the Münchhausen trilemma, the idea that all proofs need prior assumptions, or must be one of: (1) a circular argument, (2) an infinite regression, or (3) dogma, I disagree with that.

Some truths are the result of co-constraint. This is where each component of the solution is both an implication of all other components, and an antecedent for all other components. This avoids the trap of being a circular argument, when it can show that any alteration of choices leads to contradiction. Strong proofs of contradiction can be made without infinite regression.

If N co-constrained features can be shown to be consistent, and for N-1 features at least, alternatives to each can be shown to lead to contradiction, then we have a unique solution - it must be the solution. (N-1 comes from the fact, that given co-constraints that lead to one solution, any single feature can be determined by the other N-1.)

That demonstrates that constraint/determination can avoid infinite regression, with recurrent loops of implication, which don't just prove consistency (sufficient), but failure of alternatives (necessity).

Reality must have this form of being. (1) It cannot be determined by any priors or assumptions, because there are no priors. (2) It cannot be determined by infinite regress, because there is no where beyond reality to regress. And obviously, (3) dogma isn't an explanation.

Specific structure must be due to internal consistency (sufficiency), without external or unexplained facts (self-sufficiency), the demonstrated insufficiency or contradiction of any variation or alternative (necessity), and compatibility with our physics (experimental testing that can be made ever more stringent).

> This seems to be framing the speed of light as contingent on other properties of the universe, but that just pushes us back.

I agree. In terms of explaining local physics.

Local properties are most likely to be explainable with the typical regression of explanation, backed up by experimentally verified "axioms", which will then lead to deeper explanations. For local physics, we cannot just prove mathematically that a relationship can work, or even must work, but that the local conditions also require it.

Even a perfect Platonic tautological necessity for a sub-structure of reality, must be experimentally demonstrated to apply locally. We have to establish that we are "there", experimentally.

Even then, in a less pure sense, we may still beneficially use co-constraints, while also regressive knowledge. I.e. explanation = (regressive knowledge) + (co-constraint = circular consistency + inconsistency of alternatives), in order to validate both sufficiency and necessity.

Many proofs of inconsistency can rule out local solutions, without regression. Contradictions are contradictions regardless of priors.

> I could ask what explains the structure of the universe. You can then say that it's logically necessary, which is basically just saying that it's brute but with a heavier burden.

My view is, an explanation of reality will need to demonstrate sufficiency, in terms of being (1) self-consistent, (2) consistent with hosting a region with what we know of our local physics, and (3) to avoid simply being a circular argument, demonstrate that alternatives to the explanation necessarily are contradictory.

Those are three kinds of knowledge to triangulate from.

That would be an approach compatible with strong PSR.

And starting with that, I work from self-containment, self-consistency, and self-determination, as tautological constraints, leveraged as working tautological axioms.

I think it is fair to say, while some may believe a theory of everything with unexplained brut facts can be valid (some things being just what they are), few or none would be unsatisfied with a theory that demonstrated all facts were well determined, was consistent, could be shown to be compatible with our region of reality, and could not be altered without creating a contradiction.

So that is my target.