Seems to me the physical vs non physical question is a product of the philosophical heritage of object-subject dualism, a world 'out there' split off from and making contact with a subject. — Joshs

Important point. The consequences of Cartesian dualism, the apparently neat division of 'the world' into mind and matter, are one of the major factors behind this whole debate. The other is the invention of Cartesian geometric algebra, and the discovery of Newton's laws of motion. They set the stage for the development of modern science and also the philosophy that went with it. Combine it with Locke's empiricism and then top it off with natural selection, and you have the framework within which the question 'what is physical' is generally considered.

What the above definitions attempt to do is, more or less, assume dualism by giving a deflationary, dictionarial definition, where we are left with the "physical", which is what physics studies and the "mental" which, by definition, isn't studied by physics. — Πετροκότσυφας

Descartes had argued that there were two basic yet separate substances in the universe: Extension (the material world of things in space) and Thought (the world of mind and ideas). Subsequently opposing camps took one or the other substance as their metaphysical foundation, treating it as the primary substance while reducing the remaining substance to derivative status. Materialists argued that only matter was ultimately real, so that thought and consciousness derived from physical entities (chemistry, brain states, etc.). Idealists countered that the mind and its ideas were ultimately real, and that the physical world derived from mind (e.g., the mind of God, Berkeley's esse est percipi, or from ideal prototypes, etc.).

Materialists gravitated toward mechanical, physical explanations for why and how things existed, while Idealists tended to look for purposes - moral as well as rational - to explain existence. Idealism meant "idea-ism," frequently in the sense Plato's notion of "ideas" (eidos) was understood at the time, namely ideal types that transcended the physical, sensory world and provided the form (eidos) that gave matter meaning and purpose. As materialism, buttressed by advances in materialistic science, gained wider acceptance, those inclined toward spiritual and theological aims turned increasingly toward idealism as a countermeasure. Before long there were many types of materialism and idealism. — Dan Lusthaus

That is basically the framework in which the question as to 'what is physical' is being asked in my view. Materialist theories are those which assert that there is no ontological distinction between inorganic matter, organisms, and mental states. All of them are reducible to physical facts, in principle if not in practice, the practical difficulty being due to the complexity of living systems (both on the level of individuals and on the level of ecosystems). But the materialist view is that biochemistry is basically complex chemistry, which is ultimately the consequence of molecular action and understandable in terms of atomic forces, as physical forces and entities are the only ultimately real things in the Universe. And note, physicalism has to say that; as soon as any kind of real, non-physical entity is admitted, then it has lost the argument, as it is a form of monist philosophy.

One of the best-known advocates of physicalist or materialist philosophy of mind is Daniel Dennett, who has been discussed in couple of recent threads.

On the other side, Thomas Nagel's 2012 book, Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature is Almost Certainly False is an critique (as the title says) of the 'materialist neo-darwinian conception of nature', which is understood to be the dominant paradigm in the secular West, exemplified by the likes of Dennett and others.

Hempel's dilemma has already been mentioned. I think it holes any form of materialism beneath the waterline, in the aftermath of the radical discoveries of 20th century physics. Even matter just doesn't seem material any more; but that's not news, Russell noted that in History of Western Philosophy.

And that is why 'philosophy always buries its undertakers'.

Agree. This would also be one of the philosophical implications of Godel's theorem, I would have thought.

didn’t say you should, I’m simply trying to articulate it.

Sorry, my question wasn't worded well. What I meant to ask is; what does it mean for a thing to be a law of physics? Is a law of physics just whatever all things are subject to? That's the second horn of Hempel's dilemma, and makes for physicalism to be circular. Is a law of physics just whatever is part of current physical theories? That's the first horn of Hempel's dilemma, and makes for physicalism to be known to be false as it is known that current physical theories are not a Theory of Everything. — Michael

I don't have a problem with the purported circularity of physicalism, it is a metaphysical stance after all. If it were in fact the case that physics was proliferating and laws were having to be altered to accommodate new entities like, vital forces, the aether, flogiston, then perhaps the physicalist project would need to be reconsidered, but that is not happening. Admittedly dark energy and matter, and even the multiverse are new entities that have had to be admitted to physics, but they are not the result of a proliferation of physics.

One possible threat to the unification project of physics is panpsychism. If the panpsychics are right, then consciousness would have to be brought under the umbrella of fundamental physics. If that happened, then I would admit physicalism is false, though following Hempel, others might simply absorb it into their definition.

It seems I take a different view of the meaning of the "Completeness of Physics" from Hempel. I don't mean the laws of physics as we currently have them nor some imaginary perfect future theory. I mean that the deep fundamental principles of physics are manifest in Reality and will be respected by all future theories.

Physics being the science of the physical.
Physical is what physics studies. — Πετροκότσυφας

How about:

Physics is the science of the fundamental constituents of reality and their interactions.
Physical is everything that is subject to the laws of and principles that physics discovers.
Physicalism is the metaphysical claim that only physical entities exist.

Could be better worded of course, but is it circular?

How about:

Physics is the science of the fundamental constituents of reality and their interactions.
Physical is everything that is subject to the laws of and principles that physics discovers.
Physicalism is the metaphysical claim that only physical entities exist.

Could be better worded of course, but is it circular? — tom

I think so:

1. only physical things exist
2. only [things subject to the laws of and principles that physics discovers] exist
3. only [things subject to the laws of and principles that [the science of the fundamental constituents of reality and their interactions] discovers] exist

It's also vacuous. It just amounts to the claim that only the things that exist exist.

Although it seems to me that this doesn't really explain the issue. Surely people make such claims as "the fundamental constituents of reality are immaterial"? And so using the above definition(s), physics is the science of the immaterial, and so physicalism and immaterialism are identical?

I think so:

1. only physical things exist
2. only [things subject to the laws of and principles that physics discovers] exist
3. only [things subject to the laws of and principles that [the science of the fundamental constituents of reality and their interactions] discovers] exist

It's also vacuous. It just amounts to the claim that only the things that exist exist.

Although it seems to me that this doesn't really explain the issue. Surely people make such claims as "the fundamental constituents of reality are immaterial"? And so using the above definition(s), physics is the science of the immaterial, and so physicalism and immaterialism are identical? — Michael

Bit of a self inflicted injury there. Perhaps "discovers" should be replaced with "studies" or "discovers and may discover". The implication is that physics is complete, not that it is over.

I think a more frequently encountered claim is that the mental and consciousness are substances in their own right.

OK, I certainly agree that abstract concepts do not exist extra-mentally. But the problem seems to be that, for example, numbers are independent of any particular mind. — Janus

What are "numbers" ontologically in your view?

In my view, "numbers" are abstract concepts that exist in the mind. Ontologically, they exist as particular mental abstracts in the form of brain processes. That means that "numbers" are dependent on minds; they are not independent of minds. If that were so, then that would obviously mean they exist extra-mentally.

I tend to think the whole distinction between mental and physical ( beyond its ordinary commonsense applications) is fatally flawed — Janus

Strictly (and ontologically) speaking, I don't make a distinction between "mental" and "physical", so there is no problem or flaw.

What are "numbers" ontologically in your view? — numberjohnny5

I think number is inherent in nature; so number is not merely the product of minds.That much seems obvious to me.

Strictly (and ontologically) speaking, I don't make a distinction between "mental" and "physical", so there is no problem or flaw. — numberjohnny5

And yet you say you are a "physicalist" not a "mentalist". Seems like an ontological distinction to me.

The thing about Dennett's materialism is that it is made possible by a rethinking of such concepts as representation and object, and this is reflected in his embrace of connectionism, where innumerable meaningless bits in interaction replace internal representations. One could make the argument that what Dennet has done here is redefine the meaning of materialism, rather than simply reduce the mental to a Cartesian model of the natural. Richard Rorty, who is a linguistic relativist with no use for mind-body dualism, embraces attempts by people like Dennett and Andy Clark to offer new kinds of sub-personal models of perception and cognition that bypass subjwct-object dualism through recursive massively parallel distributed architectures of mind. These models do away with the Ned's for a hominculus, a little self in the brain.
I'm not saying that Dennett has completely succeeded, but I do think efforts like his point the way to a kind of materialism that is not talking about Cartesian mechanistic causation.

Precisely. That's the problem. That does not mean you can't discard the framework. — Πετροκότσυφας

didn’t say you should, I’m simply trying to articulate it. — Wayfarer

Wayfarer, judging from your reply, I think you read "that does not mean you can discard the framework".

I'm not saying that Dennett has completely succeeded — Joshs

I generally refer to criticisms of Dennett (which are not hard to find) as arguments for why materialist theories of mind are doomed to fail.

I think number is inherent in nature; so number is not merely the product of minds.That much seems obvious to me. — Janus

When you say numbers are 'inherent in nature', what does it mean? You won't literally find anything like 'a number' in nature. Numbers are only perceptible to minds capable of counting. It is said that crows and monkeys are able to differentiate between groups of 2 and 3 people, but I don't think that qualifies as counting. Given the ability to count, one can discern all manner of mathematical relationships in nature, but I am dubious as to whether that means that numbers are 'inherent' in nature. Not that it's an easy question.

think you read "that does not mean you can discard the framework" — Janus

Actually, you're correct, I did misread that statement.

The point I was trying to get across to Πετροκότσυφας was that in philosophy, when we ask 'what is physical', that question generally presumes the background of Cartesian dualism. It doesn't mean that you have to accept Cartesian dualism, but the notion of separate physical and mental 'substances' underlies the debate. The quote from Lusthaus is about the way that this developed subsequent to Descartes, with materialists/physicalists gravitating towards the kinds of explanations that could be given in purely physical terms.

When you say numbers are 'inherent in nature', what does it mean? You won't literally find anything like 'a number' in nature. — Wayfarer

Well, obviously you are not going to find fives or tens laying around; and I said "number is inherent in nature" not "numbers are inherent in nature".

It is said that crows and monkeys are able to differentiate between groups of 2 and 3 people, but I don't think that qualifies as counting. — Wayfarer

That would seem to qualify as an ability to recognize different numbers of objects. It is counting, I would say, though it seems obviously not self-reflective or linguistic counting.

https://www.scientificamerican.com/article/how-animals-have-the-ability-to-count/

it isn't time taken as a measurement system of identical units Smolen is talking about, it is the aspect of time as transformation. One could say that this aspect of time is not a mental construct. Istead of referring to it as 'time' you could talk about it as creative recursivity. If the entire history of the universe could be generated by a formula. Justthe formula itself would be enough to understand everything that would unfold from it, and time would not contribute anything useful to this understanding. But if the infolding of the universe is a process in which each present moment of time is not exhaustively predictable in a linearly causal fashion from the previous moment, then time becomes something more than an empty construct. Or one could say, the nature of objective reality itself presupposes novelty.

I think number is inherent in nature; so number is not merely the product of minds.That much seems obvious to me. — Janus

Could you specify some examples of number being inherent in nature?

And yet you say you are a "physicalist" not a "mentalist". Seems like an ontological distinction to me. — Janus

Physicalism says that every thing/object/existent is physical; that includes minds since minds are things. Mental states are distinct from non-mental states. Both mental states and non-mental states are just particular kinds of physical states.

But if the infolding of the universe is a process in which each present moment of time is not exhaustively predictable in a linearly causal fashion from the previous moment, then time becomes something more than an empty construct. Or one could say, the nature of objective reality itself presupposes novelty. — Joshs

Suppose that this is the case, that each present moment is not predictable. What does this say about the future? It is impossible that there is physical existence in the future, because what will exist has not yet been determined. Then we must assign to everything on the future side of the present, what has not yet occurred, some sort of non-physical existence.

Physics is the science of the fundamental constituents of reality and their interactions. — tom

...if you're a Materialist, and believe that this physical universe is all of reality.

I don't think there are many Materialists here.

Michael Ossipoff

"I generally refer to criticisms of Dennett (which are not hard to find) as arguments for why materialist theories of mind are doomed to fail."
Let's get specific. If you believe that Nagel's criticism of Dennett's materialism is spot on, then my response is that Nagel is in no position to critique Dennett on this issue, given that Dennett's attempt involves bridging the gap between naturalism and phenomenological philosophy, which claims to resituate the subject-object binary. I don't see Nagel as effectively grasping phenomenological or post-phenomenological philosophy. Your response to Dennett would be more effective if you could find me asomeone from these philosophical traditions who believe all materialisms are doomed attempts at incorporating mental phenomena.
You'd have to exclude Dan Zahavi, for instance, one of the best phenomenological philosophers currently writing.

I'm perfectly fine with a position stating there is nothing outside of this universe. The issue for me is what sort of materialism is up to the job of taking into account phenomena relating to the subjective, the mental, consciosness etc.
If you are against all materialisms, what sort of philosophical account do you think deals with reality better?
I ask because for me the interesting battle today isn't between materialist and and subjectivist philosophers, but between Cartesian philosophies( which includes the neo-Kantianiam of Putnam, Searle, Nagel, Chalmers and Fodor). and post-Cartesian philosophers(Rorty, Husserl, Merleau-Ponty, Heidegger, Derrida, etc).

Could you specify some examples of number being inherent in nature? — numberjohnny5

Number is inherent in nature if there are multiple things.

Number is a concept that humans developed that requires the notion of a pure identity. Numbers are purely self-identical abstractions.
Humans didn't always see the world in terms of a self-Identical counting(Piaget studied the development of the concept of number in children).

I'm perfectly fine with a position stating there is nothing outside of this universe — Joshs

By my metaphysics, this universe is one of infinitely-many systems of inter-referring abstract if-then facts about hypotheticals. Among the infinity of such systems, there must be one that matches the events and relations of our physical universe.

A set of hypothetical physical-quantity variable-values, and a physical law (consisting of a hypothetical relation among those values), are part of the "if" premise of an if-then fact.

...except that one of those physical-quantity variable-values could be taken as the "then" premise of that if-then fact.

A mathematical theorem is an if-then fact whose "if" premise includes, but needn't be limited to, a set of mathematical axioms (geometric or algebraic).

There are infinitely many systems of inter-referring abstract logical facts, including systems of facts of the types described above. As I said above, among that infinity of such systems, there must be one that matches the events and relations of this physical universe. There's no reason to believe that this physical universe is other than that.

Instead of one world of "is", infinitely-many worlds of "if".

Could the Materialist's objectively existent physical universe superfluously exist alongside with, and duplicating, the events and relations of that system of abstract facts? Sure, I can't prove it doesn't. But the suggestion of that is an unverifiable and unfalsifiable proposition that posits a brute-fact.

Anyone would agree that Materialism posits a big brute-fact.

My metaphysics (which I briefly outlined above, and will fill in better in about an hour) makes and needs no assumptions, and posits no brute-fact.

The issue for me is what sort of materialism is up to the job of taking into account phenomena relating to the subjective, the mental, consciosness etc.

The Hard Problem of Consciousness. Many or most (but not all) Materialists perceive that illusory problem. There's no problem.

We're animals. There's no such thing as Mind, Consciousness, etc., separate from the body.
We're animals, and animals are unitary. No separate Consciousness or Mind.

An animal is a purposefully-responsive device. ...like a mousetrap, a refrigerator-lightswitch, or a thermostat. ...but more complex, and influenced by its natural-selection origin.

Consciousness or awareness is the property of being a purposefully-responsive device.

A purposefully-responsive device's experience is its surroundings and events, in the context of its purposes, as a purposefully-responsive device.

If you are against all materialisms, what sort of philosophical account do you think deals with reality better?

I briefly outlined it above. I have to prepare dinner for my 2-person household now, but in about an hour or so maybe there'll be something to add, that I've left out.

...but, in the meantime, I invite comments, disagreements or questions.

In pre-existing terms, my metaphysics could be called an Eliminative Ontic Structural Anti-Realism.

Michael Faraday suggested the principle of that metaphysics in 1844.

Since then, as you probably know, Wittgenstein has been quoted here, as saying that there are no things, just facts. ...which seems to agree with this metaphysics.

(...if "things" means "things that aren't facts", or maybe "physical things". ...as opposed to its more general meaning: "Things are whatever can be referred to.")

Tippler and Tegmark have made similar proposals, but it seems to me that they've both missed the mark in various ways.

Michael Ossipoff

Whether our concept of number happens to be an abstraction of mind or not, our concept is derived from the perception of our environment.
Number is analytic, the absolute properties of any one number mean that there is always a predictable outcome, e.g. 5*5 = 25.
It is in this sense that we use number to predict outcomes or or objectify our observations, i.e. calculate lengths or distances, & calculate speed and force.
From this it seems, rather than self-identification, number is used in the process of identifying our externals through an internal process (e.g. counting).
The accuracy of mathematics and physics to describe material things and their processes means that our concept of number is accurate, but only as accurate as our observations.
Observable 'physics' is thereby limited by our own effective capacity to perceive physical reality.
For example, it is becoming evermore apparent in the realm of quantum physics that the mechanics of the subatomic world is much different to that which we perceive/observe directly.
Physics in and of itself, however, must work using mathematics. It's as easy as 1 + 1 = 2... supposedly.
In the quantum realm, calculations get much more complex and in some cases it becomes impossible to predict outcomes as we would expect; for instance, Heisenberg's uncertainty principle.
Despite the seeming unpredictability, one thing that is inherent in seemingly all things is proportion.
Whether it be in the form of quantum probability or even mass or volume, I am defining proportion as the relationship of two numerical entities in equalling a singularity.
Simply, a + 2a = 3a.
This proportion is inherent within all things that physics currently understands and can reduce to simple formula. The real problem arises in relationships we do not understand, because things don't add up when we run the arithmetic.
While number is an effective means to understand the world as far as we can observe, there is no way
to determine whether our conception of number is purely a figment of our own perception or exists objectively within reality at large, but it seems that through the bridge of our perception number is an effective way to describe reality at large, but the further we delve, the less effective number becomes.
One thing is consistent, however - proportion, where proportion is a relationship between two entities/variables.
While the world is in perpetual flux, number is absolute.
It is the relationship between absolutes that excites the state of variability.
Until again, change (function) meets constant (number).
Besides, 'numbers' by themselves aren't worth talking about. What is a number without it's relationship to other numbers? Or without it's individual proportion to a larger whole?
Self-identity has nothing to do with it.
Numbers are used to identify individualistic variables among others, such as a cat predicting it's trajectory when jumping.
It's not number how we would understand it in our model of 123456... , but number as proportion between singular entities as is the relationship between two numbers or variables that truly of interest.
Thus is the cornerstone for maths, physics, chemistry, and too biology.
Proportion either describes number or number describes proportion, but this is missing the point.
So, for all you avid sceptics: Proportion is inherent in nature. Am I wrong?

Sorry for being long drawn out and painful but I needed to go into depth.

As for the topic of physicality, 'physicality' as we describe it is contingent upon the experience of 'physicality', and 'physical' experience is determined by sensory perception.
Therefore, our understanding of 'physicality' in an objective sense is meaningless because it is contingent upon our perception to be understood within the realm of, say, physics and maths.
What is physical must be that which is an entity that undergoes physical change. Entity being, for example, photon. Physical change being for example, linear movement.
Therefore, what is 'material' is problematic, but what is 'physical' is not.
A photon is hardly material, although it does have insignificant mass.
However, a photon is involved in physical change - movement.
Therefore, a photon can be considered physical.
I'm going to leave it at this because I'd like to see some responses before I continue.

I disagree; number is inherent in multiplicity which is found everywhere in nature. Think about social animals like dogs or baboons where each individual recognizes all the other different individuals and responds uniquely to each.

bum the origin of the meaning of the word 'number' is the Proto-indo-European word for 'to divide' In other words, it is an operation performed on objects, which is what mathematical concepts are tools for. There are actually probably many different meanings for number depending on the context and purpose for which it's used. Animals cognize and respond to each other and to objects in different ways, just as we do, but does a concept like number really capture one single essence of reality, or does this term potentially refer to a variety of ways of interacting with the world? I suppose for me multiplicity could work as an irreducible presupposition for the thinking of any reality, but number is already a derived, and more complex term.

Your view of mathematics has been referred to by Lakoff and Nunez as mathematical Romanticism, the idea that concepts represent an independently existing external reality that our abstractions correspond to. Within this view, we marvel at how miraculously accurate our mathematical descriptions are. What we don't take into account is that mathematical operations are inventions. They are social constructions that evolve along with the rest of culture. Since our physics is also a construction that guides our interactions in the world rather than a correspondence or mirror of it, we've rigged the game beforehand without realizing it. Our math wonderfully describes our physical world because we've artificially carved the world up In such a way as to be amenable to our mathematical constructions of it.
That doesn't mean that our math is t useful to us, just that there's nothing platonic about it. It's a device like any other we invent.

What we don't take into account is that mathematical operations are inventions. They are social constructions that evolve along with the rest of culture. Since our physics is also a construction that guides our interactions in the world rather than a correspondence or mirror of it, we've rigged the game beforehand without realizing it. — Joshs

I think the problem with mathematical operations being 'social constructions' is that through them, many genuinely novel discoveries have been made. I mean, mathematical physics is not a parlour game, it does have obvious material consequences and even philosophical implications, which in no way were foreseen by those who founded the discipline. In fact the history of modern physics seems to comprise the discovery of ever stranger things, ideas which are literally beyond the ability of the human imagination to picture, but at least some of them give rise to predictions which can subsequently be validated. For that matter, recall that many of the consequences of Einstein's theories couldn't be tested at the time, because of shortcomings in the equipment; but over the ensuing century, as the apparatus became more sophisticated, a lot of the predictions were born out. How many times have we seen the headline 'Einstein proved right, again?' I'm not sure, but a lot more than the contrary.

So I really don't buy this 'deflationary' account of mathematical ability, nor do I think it is something that can be profitably analysed through the lense of evolutionary biology or cultural history.

Husserl said that each moment of experienced time( time consciousness) was a tripartite structure of retention, Immediate presentation and protention. In order to experience any 'now' , we are also experiencing g the passing of the just prior now, in he form of retention, a kind of trace of memory. The now also has a protentional component, an anticipating or intending beyond itself into the future. If you think about it, this makes some sense. Awareness is situated as anticipatory, as being directed toward the future.
The fact of the matter is that experienced reality never repeats itself exactly, not our perceptions moment to moment or our conceptually accessible world. So we are already used to the idea, from our own experience of it, that the future is going to evade our attempts to precisely duplicate our present or past. Rather than making future reality, however you want to characterize
it, nonexistent, it does the opposite. EX-istence moment to moment implies a certain aspect of non-predictability, of exceeding the past in some qualitative way. But that isnt normally a problem for us. For instance, our perceptual system is designed to optimize for regularities, patterns, consistencies in the flux of incoming sensation. So we don't normally notice the fact that our perceptual world is not self-identical moment to moment. It apppears that way to us because our perceptions abstract the regularities.
That is what the physical world is, a reality of constant flux, out of which we are able to extract and construct regularities.
If we try to turn these regularities into determinisms, we may preserve a prectability at the cost of a meaningful understanding of a constantly developing world.

I'm wondering how your model of if-then abstractions as a description of reality accounts for what it is that these abstractions are derived from. I don't mean an external world of material objects. I mean the moment to moment experiences that constitutes all of our awarenesses, of changing perceptual features, of affective valenced dispositions and inclinations, of fragments of meanings, etc. Arent these building blocks of the abstract facts that populate your system in some sense more real than the concepts derived from them? I guess I'm wondering how your world changes and evolves. Is it through trying on for size new ways of talking about the world?

Number is inherent in nature if there are multiple things. — Janus

I don't know if you're not confusing and/or conflating "number" with "multiple things". "Number" is a mathematical construct existing within an axiomatic system. "Multiple things" are objects or groups of objects. Those are ontologically two different "kinds" of things. The former is a mental construct that is applied to the latter. The number "2", for example, is not actually in or between two objects. If you think it is, could you specify where it would be?

So I really don't buy this 'deflationary' account of mathematical ability, nor do I think it is something that can be profitably analysed through the lense of evolutionary biology or cultural history. — Wayfarer

I really do wonder about math. Tegmark has said that all physical properties are mathematical. Leaving aside consciousness and how we experience the world, it is a very deep question as to what isn't mathematical about the fundamental stuff that makes up everything else, like electrons and quantum fields. The fact that they exist? That they have spatial & temporal extension of some sort?