Comment: 1: “The assumption, alone, that the physical universe must be consistent is insufficient to show that there is a separate MU.
The assumption that the physical universe must be consistent, plus the assumption of MR, plus the assumption that consistency doesn't matter for MU's is sufficient to show that there is a separate MU.”
Response 1: Thanks for clarifying what you mean here. I hear you, but I have been clear in the manuscript that I take the assumption of MR. And then, for assumption of the physical universe needing to be consistent isn’t really assumed, but it’s discussed, and I bring to bear a practicality argument - that it’s actually a semantic point (defining the scope of the term ‘universe’) and so I am clear here also. And the third item you mention, that it is required to assume that consistency doesn’t matter for MU: I’m not sure I agree here. I don’t think I made statements either way as to the consistency of a MU (or multiple MUs) in the work. We did discuss that consistency can be considered dependent on whether one holds one maximal MU or multiple separate MU, but I don’t think an assumption on that is needed with regards to the scope of the argument pertaining to objects being outside the scope of the (physical) universe.
Comment 2: “But you have only shown that that follows from your assumptions, not that it is actually true, ie. your assumptions are actually true.”
Response 2: Well, that’s something still. What would be required as an additional piece you would like to have available is a proof that MR is true. I’m not sure if such a thing exists, as it might be axiomatic. It’s definitely not in the scope I laid down in the manuscript but could be an interesting new topic. Hm, I wonder if it ends up being that multiple ontological views are proved valid, but it ends up being more convenient (ie less ‘epicycles’) to adopt one of them in particular and so from an Occam’s Razor perspective, one comes to the fore. But that’s speculation. Interesting point though!
Comment 3: “No, it's valid, but it's not sound. Valid but unsound arguments are ten a penny -- you can show almost anything given three arbitrary premises. https://en.wikipedia.org/wiki/Validity_(logic)”
Response 3: Ah, but that’s all I an supplying. I am sorry the work was not all you would hope it to be, right now. But these things take time and effort and that’s as far as we have got so far, unless you wish to collaborate on an extension as described above - though, I’m not sure there is an easy resolution especially if there’s a semantic component described above.
Context: But, I haven’t taken the assumption of mathematical fictionalism, in which I don’t know if I can talk about abstract objects at all—so it doesn’t apply here.
Comment 4: “Fictionalism isn't known to be true or false, neither is realism. It's an open subject. You can make arguments against fictionalism, the fictionalist can make arguments against realism.
You seem to be hinting at an argument where an entity has to really exist in order to be talked about (an argument you haven't brought before). But the plain fact is that we can talk about fictional entities, like Gandalf or Sherlock Holmes -- so the fictionalist has a robust response.”
Response 4: Ah you have misunderstood me, what I meant was I don’t have a detailed knowledge of how to construct a framework in mathematical fictionalism, and if I can define an object in that framework and refer to it in quite the same way. I don’t mean that a Sherlock Holmes or Gandalf can’t be referred to in a fictionalism, it’s just that I don’t know enough about how it set up (what os the nature of the ‘fiction’ from an ontological perspective, to know what properties it should have, or if the target of the reference is the sort of thing that can have properties (I’m assuming it can?). In MR, it seems more straightforward that if I can define an entity, it can be given an existence in an abstract sense, for the object referred to to have properties (including non-extantness) but without requiring that the object have a related extant object in the universe (such as a Sherlock Holmes who is clearly not extant even though his concept exists).
Context: I have some questions I need to clarify about how it works, and seek guidance on, to be able to argue effectively on that topic as I haven’t had it fully described to me.
Comment 5: “Can you not learn that from books? How did you learn about realism?”
Response 5: Well yes, I can, but it would be a new research topic and these things take time, as mentioned. One has to start somewhere and one can’t expect all parts of a project to be done right away, especially as research topics need to unfold incrementally to build a body of knowledge. But what you say here goes beyond just reading - I don’t know the body of literature of fictionalism/realism contains a systemisation in the way I have described in order to compare the variants that could be done. I think I would have to do that work, and so I have started here: but I picked realism because it’s a more natural starting point as mentioned, from a physics perspective and a view (at least tacitly) held by colleagues and even if not admitted, is operated under when doing daily life in the world of physics research.
Context: As I keep mentioning, where I am at, provisionally, at the moment, is that I keep running into that said Solipsism
Comment 6: “Even now? But you've agreed that the existence of mathematically describable entities outside the mind doesn't imply the existence of ontologically mathematical entities outside the mind .”
Response 6: I mean, I haven’t investigated down to the very bottom what precisely a ‘mathematically describable entity outside the mind but not leading to an ontological mathematical entity’ really is, and if it doesn’t lead to other issues, contradictions, etc down the track. I can see that it’s something that can be proposed but I don’t know if such a thing is sound, hence why the investigation as I mentioned is taking place. It sounds like it is resolved in your mind but I haven’t understood it or had it presented to me yet. It’s not enough to state a thing could be so, we need to check the consistency through and through and I haven’t seen a detailed presentation of such a thing yet (if it exists).
Context: So, can we resolve it—in the primordial universe, how are we to understand the subatomic particles being arranged into groups, and so forth, if these structures required for our existence only are fictions occurring within the mind of people? (I assume that’s what fictionalism means)… if you can clarify
Comment 7: “Imagine the library of Babel. Since it contains every story, some stories will be history, whilst most will be fantasy. But the true stories are still stories in books.”
Response 7: Thank you for this metaphor, it is helpful - here in the library of Babel, which contains every story, only some of the stories will be history, and some are various other non-historical genres. This is similar to the statement in the work I was doing, where ‘extantness’ means ‘history’ ie the abstraction projects down to relate to an actual object in the real world. Whereas there might be many abstractions (existing but not ‘extant’ and also non-existing entities means that defining them leads to a contradiction and can’t be defined consistently). So indeed only a small portion of the abstractions have the ‘extant’ property (using the world extant to distinguish it from ‘exist’ in the mathematical sense), and what I did in my formalism was to create a meta-language scoped so that the objects only ‘exist’ if they are ‘extant’, which places some limits and also structure and properties for the formalism. But anyway, the true stories (the ‘histories’) or the ‘extant’ items, are still abstractions we refer to, it’s just that they have this special projective relationship with a physical object. The fact that the formalism can only ever speak in abstractions is part and parcel of having a self-contained meta-language (and also useful as we can do inquiries on it), but the fact that you always need a ‘pointer’ to be able to included in the formalism was precisely why the Labeling Principle was imposed, which defines this property. So, here in your metaphor, it seems very consistent with the view I have, and relied upon in the work, so I don’t quite follow why the metaphor is against the view expounded somehow. I agree with the metaphor, and it is the same as my view.
Comment: "That is necessary, but insufficient , at best. If mathematical entities don't have real existence, as fictionalists cliaim, then there is also no real inconsistency."
Response: Can you say that more precisely, what is necessary but insufficient, for what?
What I stated was, from this work, based on the assumptions as laid out in the manuscript, I can verbally summarise the result by the statement that ‘abstract objects can be demonstrated to be in a distinct universe from ours, as the set of both of them together cannot be defined in a consistent way logically.’
Do you mean that these assumptions, together with the steps, don't show that these abstract objects to be in a universe distinct from ours, in the context of this formalism, and the definitions that I have supplied? OR do you mean that this statement, is necessary but insufficient to show a separate thing, ie to prove or to demonstrate some of the other concepts we have been discussing, such as MR, which I stated I did not try to prove? ie as an encapsulated logic I don't see where I went wrong.
Based on your statement, "If mathematical entities don't have real existence, as fictionalists cliaim, then there is also no real inconsistency.", I don't need to rely on there being a 'real' inconsistency for the steps to still work. What I mean is, what is 'real' or not is just the background metaphysic. A mathematical fictionalist would still hold that there are proofs and theorems, just that they don't have a 'real' existence. But, I haven't taken the assumption of mathematical fictionalism, in which I don't know if I can talk about abstract objects at all - so it doesn't apply here.
When I discuss mathematical fictionalism (note, this is not something I talk about in the manuscript), I have some questions I need to clarify about how it works, and seek guidance on, to be able to argue effectively on that topic as I haven't had it fully described to me. As I keep mentioning, where I am at, provisionally, at the moment, is that I keep running into that said Solipsism (please note, as mentioned, this is not the argument from my paper which assumes MR). So, can we resolve it - in the primordial universe, how are we to understand the subatomic particles being arranged into groups, and so forth, if these structures required for our existence only are fictions occurring within the mind of people? (I assume that's what fictionalism means)... if you can clarify
Responses:
Context: When you state ‘If MR is true, then the mathematical universe is obviously bigger than the physical universe,just because most maths isn’t physical’ doesn’t follow, in my view. Why would MR being true mean that the mathematical universe is necessarily bigger than the physical universe?
Comment 1: "Because most maths isn't physically applicable, as I stated, and you agreed."
Response 1: I do agree that most maths isn't physically applicable, but that doesn't mean that for MR, the MU is obviously bigger (to clarify, for MU here, do you mean physical+maths, I am assuming not). For example, I might have many physical objects in my universe, and not all being mapped to by a mathematical abstraction. I have no way of ensuring that the universe is all totally mapped to. I make a supposition that in physics, we hold a view that it can (or should be). But I don't know for sure, and so the relative sizes of physical + mathematical parts is hard to define. It may be the case the the mathematical part is indeed larger, but the fact that most maths isn't physical doesn't guarantee it, it would be something to do with limits on the size of the physical universe, and/or the scope of mathematics obtruding into it. Maybe most physical doesn't get mapped to (though, I don't believe that currently, it could definitely be proposed).
. But having a brief look, I’m honestly not sure how to match my work to this definition of supernatural.
Comment 2: "You have a communication issue, because you are not using "supernatural" in the expected way, and a PR issue, because a lot of your intended audience are going to reject the supernatural out of hand. Whence the downvoting."
Response 2: Thank you for the view. The way I see it though, it is actually a good communication method, in that I have excited some commentary and engagement from the community - such as yourself - you have been very generous with your engagement. The rejection out-of-hand though accidentally demonstrates that the audience might not have been as attentive as they might pride themselves on, however, which itself is a useful insight to note.
Do I have to? I am anticipating my work can be standalone and not to try to use another person’s definition of supernatural. Here, I use it purely as ‘not in the universe’ where I’ve defined the universe in the way I describe in the work.
Comment 3: "You need to communicate clearly , and you don't need to repell the reader"
Response 3: I am attempting to communicate as best I can, and am limited of course by my competence. Apologies if it doesn't come up to scratch - I am doing my best. I also am not intending to repel the reader, but get some engagement, which was successful.
Also, the 'do I have to' was in the context of whether i need to match my work to this definition of supernatural, not based on communicating clearly, per se. I wasn't aware of the work, but how else do I generate discussion to get some improvement from the lesswrong community? I have to start somewhere. I was as clear as my faculties allow. I tried to define the supernatural the way I see it. A comparison of that view and another work seems like a different topic beyond the scope of this post.
- “Between mathematical realism and mathematical fictionalism , or between mathematical realism and naturalism?
The inherent contradiction I was meaning here was more the former: a Naturalist is bound into believing that the natural laws, mathematical principles governing nature (and so forth) are part of nature or an emergent reality,
Comment 4: Again, that's not the same thing. The existence of X-ishly describable entities doesn't imply the existence of free-standing X's. For instance, we can describe the colours of external objects using the trichromic RGB system , but it's definitely not out there.
Response 4: I didn't say that the existence of X-describable entities implies free standing X's. The idea of free standing X's, ie a kind of Platonism is not something i set about to prove. I believe I assumed it as a starting point, and wanted to see how far I could get with it, as an exercise. So I wouldn't argue it that way. I do state in the above quote that the Naturalist was bound to believing natural laws (by definition) and that I take it to mean that mathematical principles governing nature emerge from this same (physical) universe, as opposed to a more Platonic view of Mathematical Realism (ie. "out there" as you put it). Is that untrue? In regard to such a Platonic view, I would take it that the colours of objects using an RGB system, which are both concepts (the colours, and the RGB system) are abstractions that have an existence, and would be included as one of the abstractions in my formalism, that then get projected down in a reverse-epiphenomenal way, onto the physical-world object. (ie they are attributes of it, and attributes are abstractions).
Responses:
Context: I haven’t thought of how to construct an Ansatz in a framework built from an arbitrary metaphysic
Comment 1: "I have. There's almost nothing to it, if Ansatz means nothing more than some guessed-at mathematical descriptions turning out to be right.. and that is the . description of Ansaztz you give here:- (etc) ..then, so long as some things are mathematically describable, some mathematical descriptions will describe them, even if guessed randomly"
Response 1: Hang on, what I mean is, constructing an Ansatz completely from scratch, without any assumed structure doesn't sound like something there would be 'nothing to it' - I would expect that if you have one, you'd need to be careful not to accidentally smuggle in an assumed concept from the get-go, which hasn't been demonstrated yet - it's hard to come to any logical machinery or systems from scratch without assuming something, without any structure or rules or symbols at all. Even if it is very simple, you have to start from somewhere. I tried to keep mine very general, and a few items of structure were added as minimally as possible. But what I mean is, the very concept of an Ansatz itself is automatically couched in some framework - I don't think one can have a concept unless one at least has a framework for the concept to be part of, or to exist in, so I would assume to even invoke the concept, a framework (even a skeleton one) has been assumed.
Comment 2: "(We don't know where Ansatze come from in a detailed way, but it's hard to see why that would need a supernatural/metaphsyical explanation, since we don't know where "think of a number comes from", but don';t doubt that it is an ordinary psychological process. The whole rhetoric surrounding Ansatz, or guessing as I like to call it, is overblown, IMO)."
Response 2: In terms of where Ansatze come from, I don't think we do know quite where it comes from but we don't need to know for the purpose of this investigation yet - it's simply enough that we require logic to exist, and for there to be an abstract concept that can be invoked - very little else in the proof was assumed. The supernatural explanation (again, being careful to define what I mean here by supernatural, that is being outside the physical universe) comes about naturally, with only some minimal rules of logic being invoked. We might not know 'where' "think of a number" comes from, but we do know that the number is consistently definable, it 'exists' (that's taken based on an MR viewpoint though), and it gets instantiated a lot, in the physical universe - ie the physical objects obey (and have an intimate relationship with) these mathematical objects.
In terms of the psychological process by which we access it, the psychology would be developed from brain structures, and those are based on proteins, based on info from genes, on chemistry, on physics, down to the smallest particle, so at every level, we have seen a great deal of natural processes are respecting mathematics, and we can write down these laws. So it would come at no surprise that our brains are also structured and follow processes. But, you wouldn't argue that if the brain was destroyed, that the concepts being referred to by some maths would be destroyed, nor would an atom being destroyed mean the concepts of mathematical groups an equations of motion would be destroyed. Surely those are just all instances but not the thing being referred to itself. (ie they are not the mathematical truths themselves, as those truths turn up in all sorts of places).
Apologies if the rhetoric seems overblown - can you specify in what way? As above, I haven't quite got your view in mind re mathematical truths. It seems you can't have no metaphysic, we all have a metaphysic in mind, just it might be undeclared or unexamined - so I am interested to learn yours - it seems yours, to you, seems preferable, but I am unclear of your statement of it.
Comment 3: "But Wigner brings in further issues -- the issue that a guessed-at mathmaticlal structure which is intended that is intended to describe one phenomenon, can be applicable to others. And you mention , in relation to Dirac's relativistc wave equation, the ability to make successful novel predictions.. The various sub-problems have various possible solutions. "
Response 3: What are the issues raised by Wigner issues for? ie it seems consistent with the metaphysic I have adopted. Many different mathematical mechanisms can be applied to describe processes. It happens all the time in particle physics. There's a concept of a 'Representation' of a group. Subatomic particles are arranged into Groups, which have a certain mathematical structure. But a group is quite general, and you can represent a group in different ways. One particular group might have many different representations, one using matrices, one using complex exponentials, all sorts. These representations have the group structure, but they add more, adding specificity, and are called vector spaces. You could use one machinery to look into a physical phenomenon, or you could use another. Both could apply. Hence why it is hard to have a prescription for how to 'select just the mathematical truths' applicable to the physical universe so as to bolt them on and get a consistent P+M Universe (hence why I don't go down that route).
Comment 4: "An ontology where the universe is based on a set of small set of rules explains the unreasonable effectiveness well enough: since each rule has to cover a lot of ground, each rule has multiple applications. And such an ontology is already fairly standard."
Response 4: The universe being 'based' on a set of rules is an interesting phrase, as it does seem similar to my version of MR - ie that there are rules, and those can be talked about in a meta way, regardless of physical universe, and then the physical universe can be talked about as following those rules. I also agree, since it is the view I was expounding, that this leads to an explanation of the unreasonable effectiveness, but the way I said it was different - I just counted the countably-infinite number of possible abstractions that could apply to a phenomena in a physical universe, and the seemingly 'smaller' (more restricted) countably-infinite number of abstractions applying to phenomena that also are extant in a universe, and found them to be of the same Cantor cardinality.
Comment 5: "There's also an underlying problem that saying "I can solve X" has two meanings: "My assumptions are the only solutions to X" and "I have the latest in a long line of putative solutions" It is not enough to succeed, others must fail."
Response 5: It is true that a phrase like 'I can solve X' can have an ambiguity. I take it to mean the latter though, in other words, taking some assumptions, and working through some steps, one can arrive at a valid solution - which in and of itself has merit, without stating whether other approaches can get to the same point. One might point out the neatness (less 'epicycles') or more (or less) in line with Occam's Razor to evaluate a purported solution after it is given - but I wouldn't say that means a solution hasn't been given. Certainly in my work I don't state it's the only way, it's much smaller than that, as a claim - just that this way seems to hold up, seems neat, a lot of things fall out of it 'for free' (ie it solves the problem with low entropy, without over-engineering extra unnecessaries) and it also seems to align with thinking drawn from multiple different fields of knowledge which is usually a detective's 'hint' in the right direction, during an investigation.
Responses to questions, also thank you for your patience - there seems to be a misunderstanding under the surface that we are both approaching, perhaps in terms of terminology that is causing some of the disagreement:
Comment 1: "The universe meaning the physical universe? But that's an argument against MR."
Response 1: Yes, the universe meaning the physical universe, and I am taking Mathematical Realism to mean that the mathematical statements are real (they exist) but not in the physical universe. If one defined Mathematical Realism as compelling the inclusion of mathematical objects into the physical universe, then I don't hold that. This position is about demonstrating how the putting together of mathematical objects in the physical universe means the new composite universe can't be consistently defined. So the real mathematical objects have to be outside the universe.
Context: Putting it another way, adding mathematical concepts in the way described, without limiting the scope or doing something to handle the Cantor paradox, leads to a definition of the universe that’s logically inconsistent
Comment 2: "Which universe? Are you talking about a single maths+physics universe? (as opposed to Platonism)"
Response 2: Leading to a definition of a universe that is a single maths+physics universe, which can't be defined consistency. Which means we end up dispensing with it and then having something closer to Platonism.
Context: Am I saying the mathematical universe is inconsistent if it exists at all? Well, not really—I don’t know if there is a ‘mathematical universe’ per se.
Comment 3: "You can specify which kind of MU you are talking about, as a hypothesis. (although at this point I am not even clear whether you are for or against MR."
Response 3: I don't specify a MU as I don't assume such a one exists, in an encapsulated way. I specify that we hold that mathematical truths are real (exist) and show that they need to lie outside the physical universe. I think this must be the heart of the confusion - there must be a definition of MR that is different from the way I am using it. It appears as though, in your view, that having something 'exist' means it needs to be encapsulated either in a) a universe, or b) the physical universe so they ar combined together. (Not sure which you are assuming), whereas I had not taken MR to mean this, otherwise the work wouldn't make sense. Apart from the terminology, I rely on the definition of the physical universe in the manuscript, ie Eq(68).
Context: Totally agree that mathematics being a kind of encapsulated universe consistent with itself would undermine its own truth,
Comment 4: "I didn't say that. The problem is that it doesn't make any difference to our activities -- we can't tell whether the axiom of choice is true by peaking into Plato's heaven. So it's a huge amount of additional entities that don't do anything, in practice."
Response 4: Ok, we can't tell if an axiom is true (by definition of what an axiom is) as its one of the building blocks for a particular computational logic we may choose to define, L. Now, if L is embedded in some other framework, a meta language, we may be able to make some statements about the axioms, but not from within L itself. But, for a given L, and its axioms, the truths would be statements that are formatted as theorems, which can either be proved or take the format of a Goedel sentence (ie only proved from outside L but not from within, unless the consistency of L is undermined). In other words, the mathematical truths and realities that we can 'peek into Plato's heaven' to see, aren't the axioms, of a given L (in the context of L, unless we go outside of L), they are of the format "given a and b" (where we can make 'a' and 'b' anything we want), "then c follows". So I am stating that such a truth holds true, for my selection of 'a' and 'b', regardless of whether one is in a physical universe or any other speculated other physical universe. ie I am asserting that these mathematical truths hold in any physical universe as a meta language, as I can choose anything I want for 'a' and 'b', then logic of 'c' holding up in the context of the system 'L' I have defined, is immutable and true.
Context: We know that its not as large as ‘anything I make up’ because there are theorems that lead to contradictions and that limits the mathematical objects that are ‘real’ (in the mathematical sense).
Comment 5 "...and there isn't a unique non contradictory MU either."
Response 5: Fair - indeed there wouldn't be, as there are many different systems of logic, say, I could define (different L's, as mentioned above, for instance) that could all be internally consistent. I don't however state that there is such an MU encapsulated. I only really explore the physical universe and whether we can bolt-on mathematical truths to it or not. Believing mathematical theorems are real truths that hold everywhere (regardless of what universe), and finding that we make the definition of the universe tricky if we definite as the physical universe + mathematical truths, I concluded that, adding mathematical all truths enters a Cantor universality paradox. However, you could for example, argue for a subset of mathematical truths (just the ones that apply to the physical universe in some way) and bolt it on to the physical universe to make a new type of MR. I haven't seen a prescription for how this could be done though in practice. e.g. it's not clear a given phenomenon can even have a single mathematical prescription applied to it. I could use complex numbers, or matrices, or other types of vector spaces, to achieve a similar end - the mathematical machinery isn't necessarily unique when applied to their relevant targets in the physical universe, and yet all these mathematical theorems and the objects they operate on are different entities - so where does it end? (ie how can we prescribe how to limit the mathematical theorems that might get bolted on to the physical universe to make a new universe including them all, so as not to run into a Cantor paradox)?
Context: So I don’t see this as an argument against realism
Comment 6: "The argument is that the MU is either maximal and inconsistent, or non-unique., ie indefineable. Both are problems.
Plus the Occam's razor problem."
Response 6: If i understand correctly what MU means here, that is some set that includes at least enough mathematical objects to encounter a Cantor paradox), then I agree an MU being maximal makes it undefinable consistently. But the other case that, if it is split into smaller/limited subsets that don't encounter that, then there are a multiplicity of them, and not a unique MU, I don't know if this second option is a separate problem though. If I arbitrarily separate them out into different components, and I select one of them (perhaps a candidate to bolt onto the physical universe to define a phys+math universe), I can still ask if the remaining ones I left out are 'true' or 'real' and whether they are in this newly defined universe.
I don't know of any prescription for selecting such a limited candidate subset though.
Context: ‘Smaller but consistent’ MU—I’m not sure what you mean here—the ‘smallness’ would come from leaving out non-truths, ie contradictions,
Comment 7: "It would come from leaving out one side of a contrdiction, ie. there are two smaller universes for every contradiction."
Response 7: Ok, which amounts to defining a smaller calculus, like an 'L', which has only certain axioms, contains only certain structures and is limited to only certain theorems.
Context: But also I think MU (does that mean ‘mathematical universe’) is a potentially misleading term as I just described above.
Comment 8: "So.,,,have you a better one?"
Response 8: I was actually going to ask you the same question, but for MR - if it appears my definition of MR is different from what you had in mind, what should I call my thing, if the naming convention is causing confusion? Essentially what I meant was the math I wrote - the words are hard to get right as people come at the problem with different background of terminology usage.
For your question here about a better term for MU, I think we can retain it but clarify the different concepts. In one case, MU could be used to mean an encapsulated system (ie a universe) of mathematical theorems. Or in one case, it could mean one of the completely consistent definable subsets of it. In another case, it could mean the physical universe + a bolt on of either all or a consistently definable subset of mathematical theorems (ie both physical + math together). Maybe we should call the latter, 'PMU'?
Cont'd (2)
8. "You seem to be blurring "whether mathematical realism is true" and "what are they implications of MR". If MR is true , then the mathematical universe is obviously bigger than the physical universe,just because most maths isn't physical."
I wasn't able to perceive the blur between these two items in my quote: "!!!! That’s not at all obvious, in fact, I’d never heard it before until I began looking into this. If it’s obvious now to many people, that’s great! Perhaps the cultural mindset is different compared to my younger days. Certainly the most common view I run into among academics ‘spoken’ is that maths is included in the physical universe as a kind of ‘convenient fiction’ and the physical universe is there is, but then in reality they often kind of tacitly adopted this kind of mathematical realism—I wanted to explore why there’s some unwillingness to face this hypocrisy... (etc)"
I'm simply relating to you what my experience has been in regard to the conversations I have had. The observation that some people will state they adopt a view, and then operate with another view, is not a commentary on whether MR is true or not, or whether I believe it to be true. It's something that I noticed, and I have in this work taken a stance of MR being true.
I've tried to be as clear as I can, and I havent deviated from the same point that I, A) adopt MR (I give some context as to why I think it's reasonable and a natural view, for my own part), and then B) I develop a formalism assuming it, in the format that I describe (there may be other variants) and then I work through some of the implications of the formalism. I feel like I'm repeating myself over and over to you, I'm not quite sure why it's not clear.
When you state 'If MR is true, then the mathematical universe is obviously bigger than the physical universe,just because most maths isn't physical' doesn't follow, in my view. Why would MR being true mean that the mathematical universe is necessarily bigger than the physical universe? The only way I can see it being obvious is if you are defining the 'mathematical universe' as the physical universe and the mathematical part altogether. Perhaps that's what you mean, but you didn't state it.
In the work I have put together, you can see that what I am showing from the formalism is that extending the physical universe to encompass the mathematical truths runs into some practical issues, and instead defining the universe as being smaller than this, necessarily leaves out some objects that are now not in the universe.
9. "Assuming realism...?" As mentioned, yes the formalism takes MR as a backing metaphysic as previously stated.
10. "The first google match for "Carrier supernatural" is... https://www.richardcarrier.info/archives/7340# "
Ah, I haven't read this author before and didn't realise Carrier was the name of an author, I had assumed it was a jargon coined on here perhaps. But having a brief look, I'm honestly not sure how to match my work to this definition of supernatural. Do I have to? I am anticipating my work can be standalone and not to try to use another person's definition of supernatural. Here, I use it purely as 'not in the universe' where I've defined the universe in the way I describe in the work.
I mean, it's interesting, but one thing that makes it difficult to do matchup with another work is some of the terms don't appear to be carefully defined enough, e.g. "Tautologically a natural world is a world with nothing supernatural in it, and a supernatural world is a world with at least one supernatural thing in it." It's not clear to me what a 'world' is, here, or how it is intended to relate to the kinds of realities I am talking about.
11. "Well, maybe aren't using, or don't care about the literal definition."
In that case, umm. I got nothing. If people are using different definitions or don't care about the literal definition, it doesn't really impact the meaning of the work I am trying to do here.
12. "Between mathematical realism and mathematical fictionalism , or between mathematical realism and naturalism?
The inherent contradiction I was meaning here was more the former: a Naturalist is bound into believing that the natural laws, mathematical principles governing nature (and so forth) are part of nature or an emergent reality, in some versions, it is present in our mind, and yet with the other hand, will operate as though there was a 'math land' where only some items from that apply to our universe. Both valid points of view but incompatible.
In the latter case, you could totally have a Naturalism that extends the physical part to encompass the abstract and mathematical part, as described above, though it need to be done carefully and some methods of doing that can result in contradictions (the 'draw a box around everything' scenario). I apologise for the confusion that these are two separate points.
13. "Re: the latter.. If they think of the supernatural as gods and ghosts, as most people to, then there isn't because mathematical realism doesn't entail anything like that. I think the ghosts and ghoulies definition is what people care about."
I hear you, but then that mixes in some folklore aspects adding another dimension of complexity. In this post (ie not the article, but the post) what I noted was that this opens the door - once you admit one supernatural supervening, it demonstrates at least one case where it can occur. I'm of the view that the folklorish aspects in humanity don't come from nothing, and while many of the folklore stories may not be true, they keep coming up in every culture. I've been thinking for a while that the difference between a 'demon' and a 'mindset' seems slight, and there might be some truth to the idea that the abstract has a more 'real' aspect and dimension than people are in the habit of believing right now. That the mind is participating in real, genuine discovery and creation when it deals with mathematics.
And also, it doesn't matter what people think or care about, let's work out the truth first, and then we need to believe it, regardless of how uncomfortable it is, or what previous propaganda says, or it has a bad reminding taste of some folklore. So many weird physics things that seem unbelievable and seem crazy I have had to accept over the years as truth. If it's true it's true, and I think these aspects are also talked about in the neurology book The Master and His Emissary by Iain McGilchrist and his follow up book 'The Matter with Things', which argues that both the 'Reality-Out-There' and the 'Made-Up-Miraculously-By-Our-Minds' views of reality are both false, and that there is a contribution from both the observer and the environment at the same time in creating reality. The reductionist view of nature to boil it down to something more objective, you can see, is actually highly stylized, attitude driven and not objective at all.
(Cont’d) apologies, this is taking some time and I will do this in parts as I will run out of time here and there. Bear with me.
Did you read the paper? It’s not the existence of a mathematical universe that is used to show it, but, given the framework, I use a cardinality argument - so there’s more work and proofs and theorems in the paper - I just summarise the cliff notes in this post for the lay audience. What I do is use a very general statistical observation only, rather than trying to link up individual objects to theorems, I look at the relative size of the spaces. What I have explored is the connection between a separate universe in a framework where the mathematical principles can be used to describe things in many universes, the reverse-Epiphenomenal view. Also, I haven’t totally rejected a Tegmark view, it just needs to be subtly qualified - ie the mathematical parts tied together with the universe can’t be unscoped, one is limited by Cantor’s Theorem here.
The result: Equation (54) in the paper. I brought it up because it was interesting, and I hadn’t seen a cardinality argument before. If by UEM you mean Universal Existing Mathematics, well that’s not what the work is trying to demonstrate. It seems like you intended this work to be about proving UEM, and are frustrated that it doesn’t. I’m confused because that’s not what I set out to do and it’s interesting, but not the topic I am looking at.
The reason for my aside, was it was an example of what could be true - I’m trying to say I don’t necessarily hold that the universe is always structured and reasonable, it might not be. What I did was assume it, and show the result. I certainly don’t prove it. It would be interesting to get more data and explore these things. But in the case where the universe is reasonable all the way down, then this would hold. It seems like you wanted me to prove or disprove something which isn’t the topic I set out to do. You can do it if you want. (Cite my paper though :)
I’m really not following you now. I adopt Mathematical Realism for the reasons stated, its a philosophy that’s reasonable and also aligns with the working ethos of physics and mathematics. What other popular flavor should I have chosen?
Ah ok, so the solipsism goes as follows. Note that this does not constitute a proof, it’s really more pointing out a metaphysical convenience, where physicalism on the other hand needs to jump through some more subtle hoops and goes a little against Occam’s Razor. That is: in the specific version of physicalism that seems mathematical entities as nonreal, and fictions that exist in the human mind, then structures that pre-date humanity, like the mathematical groups associated with particle behavior in the early universe, couldn’t’ve existed back then. So I intuit that the actual structure is timeless and not incorporated easily into the universe that way. It’s not the only way, there are other versions of physicalism.
For a mathematical universe, it only isn’t obviously contradictory if it is constrained in a way to avoid the Cantor problem. But what I mean is, people are clearly accessing many mathematical truths beyond that that don’t specifically exhibit in the universe, (aside: unless you count the thought process itself as the exhibition, but then as its a question of will and enterprise, it could be arbitrarily expanded with effort which still puts the bound at a level where we could say the universe is expanding into something, the thing which it is expanding into suffers the Cantor problem.)
And a point here not mentioned is your comment is that these mathematical objects if coupled to a normal universe still exhibit different properties: they don’t have a location, they are timeless, they don’t exhibit many of the usual attributes of physical objects etc.
The statement of physical objects not inherently being non-mathematical is a good one - I like that. Clearly there is a deep link between mathematics and nature as the mathematical attributes get exhibited in many places.
I really don’t need to show that - as mentioned previously, I am not attempting to demonstrate Mathematical Realism, but I give some background as to why I chose it, and then I assume it to explore some consequences. Assuming something different would be interesting but its a different project and beyond the scope of this work at present. I haven’t thought of how to construct an Ansatz in a framework built from an arbitrary metaphysic - perhaps you can’t, perhaps each one is done on a case by case basis. I simply chose a metaphysic that seemed the most sensible and aligned most closely of the working ethos of myself and colleagues, working in physics - it’s a starting point. I would anticipate that you could still construct an Ansatz approach in a different framework - and that there are some caveats that need to be resolved ie it couldnt be constructed in a naive way - it certainly doesn’t strike me that the Ansatz part of all this is the thing that would threaten non-realism necessarily but I haven’t explored that. And I agree re your comment randomly guessing models. I certainly don’t know for certain, nor prove, that there is not a component of the universe not modellable in this way. Before I started this project, me and a colleague often thought about what if it is not.
Yes - fair enough — to clarify that, in that quoted sentence, when I said ‘non-mathematical entities’ I actually meant physical entities, rather than eg non-truths/falsehoods within mathematics (eg contradictory theorems and so forth).
That is a good pickup, and a good fix as I try to describe it in english language terms.
Your sentence is clearer.
Hi Tag, I didn’t hear back from you so I suppose I can assume that my explanations were satisfactory and I had now resolved the qualms as previously raised. Thank you for your attention.