Kelly Ross' essay Why I am a Platonist contains an analysis of Kant's response to Hume's 'is/ought' problem.

Interesting essay.

Quick reaction from a non philosopher. So often in philosophy argument seems to come down to the view that we require transcendental justification for morality or aesthetics for them to be meaningful. Values can't be coherent or even brought into being without either God and/or a version of idealism. In other words, idealism or god are the necessary requirement for ineligibility. The logical absolutes and even the existence of language could be claimed to be dependent on this too.

The idealism of our present time seems to be this notion of inter-subjective communities of agreement which help us to establish shared but subjective truths. In the era of the dead metanarrative this seems as optimistic as we are able to be about truth, beauty and goodness.

I think the latter approach resonates stronger for me but I understand the powerful narrative and tradition of the first. The first seems to say that right and wrong and notions of beauty are a kind of magic that are inaccessible to secular thought. I certainly know that there are Christians with presuppositional apologetics who would argue that atheists are indeed able to tell right from wrong, but only because God wrote this knowledge 'upon their hearts.' Perhaps another vestigial trace of the Logos in Neo-Platonist guise.

*

Spot on. The 'realm of quality' or 'domain of value'. Why modern philosophy can't go along with that, is because of the conviction that the Universe is empty of meaning, and meaning is always only a social or subjective construction - there is no 'real meaning' as it were. Perhaps it's innaccessible to secular thought because that is intended or defined in such a way as to exclude consideration of such ideas. See this post again.

What keeps leading back to this trail is the reality of intelligible objects, which I've just posted about in the thread on non-physical realities. (I've been corresponding with Kelly Ross, he's quite an approachable fellow. I don't agree with all his analyses but they certainly help me get my head around a lot of difficult issues.)

Re-visiting this thread because the book I've just read, Mind and the Cosmic Order, has provided a new interpretive model for 'the noumenal'.

This is the first paragraph in the introduction:

Let’s begin with a thought-experiment: Imagine that all life has vanished from the universe, but everything else is undisturbed. Matter is scattered about in space in the same way as it is now, there is sunlight, there are stars, planets and galaxies—but all of it is unseen. There is no human or animal eye to cast a glance at objects, hence nothing is discerned, recognized or even noticed. Objects in the unobserved universe have no shape, color or individual appearance, because shape and appearance are created by minds. Nor do they have features, because features correspond to categories of animal sensation. This is the way the early universe was before the emergence of life—and the way the present universe is outside the view of any observer. — Pinter, Charles. Mind and the Cosmic Order (p. 1)

What the observer brings is the picture:

When we open our eyes and observe the world around us, we don’t see a smooth, evenly distributed continuum, but a scene that is sharply and unambiguously divided into separate objects. Each of these objects is familiar to us, we know their identities, and we are able to name them. To the animal [i.e. sensory] mind, the world is subdivided into separate, discrete things. Without a separation into independent parts, nothing would be comprehensible, there could be no understanding, and thought would not be possible.

...Common sense has us believe that the world really does consist of separate objects exactly as we see it, for we suppose that nature comes to us ready-carved. But in fact, the animal visual system does such a thorough job of partitioning the visual array into familiar objects, that it is impossible for us to look at a scene and not perceive it as composed of separate things. — (p. 67)

He makes the point that the scientific 'view from nowhere' comprises nothing more than, or apart from, the formal relationships of objects and forces without any features:

with no color, appearance, feel, weight or any other discernible features. In fact, every feature which might impact the senses—hence produce an impression of some kind—is absent because in this hypothetical universe there is no life and there are no senses. Everything material may be there, but not the senses. As Kant said about the noumenal world (which is the same as the mind-independent world), nothing can be said about its objects except that they exist. — p.118

So in this usage 'the noumenal' actually conforms with its dictionary definition, that being a 'pure object of thought' (with the caveat that 'thought' here means 'quantitative expression'.) He points out that the formal objects of science do not comprise any kind of image:

When you speak of a straight line in science, you must suppress the image of the taut string in mind. You must force yourself to forgo any mental picture of what a straight line looks like, and instead, think of it as nothing but an empty word. When you use that word, you may hold the image of the taut string in mind, but that’s for your own benefit: It may guide your intuition but should not participate in your reasoning. ...If that were permitted, then the laws of science would depend on the meanings we attach to concepts—on the mental images we hold in mind. — Pp118-120

He says that science proceeds by the 'addition of simples' meaning the discovery of the simplest quantitative elements which can combine to produce complexity. But the structure of complex phenomena are brought to them by the perceiver:

Newton’s equations, which apply to pairs of bodies in space, determine the trajectories of planets around the sun. However, these trajectories are meaningful only to beings who see and conceive in Gestalts. The shape of an orbit, though it exists only in the eyes of a Gestalt observer, is a direct consequence of Newton’s laws, and no further principle is needed to account for it. Although the shapes of orbits are fully determined by the underlying physics (that is, by addition of simples), orbits exist only in the scheme of reality of Gestalt observers. The reality which a Gestalt observer perceives is quite different from that of the underlying physical world. In the Gestalt whole, the observer sees patterns—and these patterns do not exist in the ground reality because patterns emerge only in spread-out wholes and exist only in Gestalt perception. — p124

However, thoughts are real, but in a different sense to the formal objects of scientific analysis:

Sensations, beliefs, imaginings and feelings are often referred to as figments, that is, creations of the mind. A mental image is taken to be something less than real: For one thing, it has no material substance and is impossible to detect except in the mind of the perceiver. It is true that sensations are caused by electrochemical events in a brain, but when experienced by a living mind, sensations are decisively different in kind from electrons in motion. They are indeed “figments” because they exist nowhere except in awareness. As a matter of fact, they exist only as claims made by sentient beings, with no material evidence to back up those claims. Indeed, brain scans reveal electrical activity, but do not display sensations or inner experience. — (p. 52).

Pinter advocates for a form of dualism but it's exceptionally clear and quite simple. And it does dovetail quite well with Kant's transcendental idealism except that he doesn't go into the nature and structure of reason, as such - although that would have made it a completely different book. One of the main advantages of this book is its clarity and focus. It has really helped me to understand the sense in which the world is 'mind-generated' - not the world in its entirety, not the whole vast universe of space and time, but 'world' as, and insofar as it is, a meaningful whole - which is the meaning of 'cosmos' - and in which the mind plays a fundamental part.

the meaningful connectedness between things — the hierarchical organization of all we perceive — is the result of the Gestalt nature of perception and thought, and exists only as a property of mind. These insights give the first glimmerings of a new way of seeing the cosmos: not as a mineral wasteland but a place inhabited by creatures.

:up:

Does Pinter account for what generates the structure and properties of (the) mind(s) which generates the structure and properties of the world / cosmos?

One of the main advantages of this book is its clarity and focus. It has really helped me to understand the sense in which the world is 'mind-generated' - not the world in its entirety, not the whole vast universe of space and time, but 'world' as, and insofar as it is, a meaningful whole - which is the meaning of 'cosmos' - and in which the mind plays a fundamental part. — Wayfarer

Thank you - this is helpful. Food for thought. I can see how this is all compatible with phenomenology. I guess the aspect left out of this - the nature of and structure of reason - probably does also need to be engaged with to make the entire 'vision' coherent.

Does Pinter account for what generates the structure and properties of (the) mind(s) which generates the structure and properties of the world / cosmos? — 180 Proof

He does say that 'the animal sensorium' is present in even the most simple of sentient creatures - the example he gives is an insect type called fairyflies, which are tiny, 0.13 and 0.25 mm, but which have organs for digestion, reproduction etc. His view is that from the earliest species, animals form gestalts of their environment in order to negotiate it, so that what is meaningful to a species are the gestalts that are shaped by their purposes, which in turn are shaped by the exigencies of survival. He discusses Donald Hoffman for several pages.

What Hoffman  claims is that the way objects appear to us is dictated by considerations of fitness and not realism. What an animal experiences seeing may be unlike a high-fidelity reproduction of reality, with all its complexity and inscrutability—yet it may be far more helpful when the animal needs to size up the current situation correctly and act appropriately. The claim is that so long as all the experiences a creature has with objects are consistent with one another—with no discrepancies of any kind—the creature is far better off interacting in mind with usefully simplified and schematized replicas.

Pinter, Charles. Mind and the Cosmic Order (pp. 12-13). Springer International Publishing. Kindle Edition.

More on Hoffman's theories can be found here.

I don't see how that – panpsychism? – answers my question.

I can see how this is all compatible with phenomenology. — Tom Storm

Don't miss the main point.

No, Pinter does not try and explain the origin of mind. Wise choice, I think.

I read Hoffman's book recently. It's pretty good. I was a little disappointed that it didn't go into any of the research on the way information about the noumenal makes it into the mind. Information theoretic approaches cover this quite well IMO, even if they can't solve the hard problem, so it seemed like a bit of a hole.

I’ve only read the Hoffman article I linked to, though probably should invest some time in the book. At first I was sceptical about Hoffman but I’m beginning to see the sense in what he’s saying.

In my post about Pinter’s book above, I specifically mention where in his account he says the noumenal enters the picture. It’s not at all as I would have thought - not some ghostly backstage thingimy, but the purely quantitative attributes of the ‘simples’ of scientific analysis.

My philosophical interpretation is close to what Pinter hints at: that sentient beings bring meaning into a meaningless universe, they open up an experiential dimension to existence which is otherwise absent. (That's why we're called 'beings'!) The fundamental problem with modern philosophy and science is in regarding beings as objects, rather than recognising that their nature as beings will always elude objective analysis, and the concommitant belief that the universe depicted by science is the only real universe, thereby forgetting the role of the observing mind in bringing meaning to it. (I think this is what Heidegger means by the 'forgetfulness of being'.)

It’s also close to what Nagel says:

We ourselves, as physical organisms, are part of [the] universe, composed of the same basic elements as everything else, and recent advances in molecular biology have greatly increased our understanding of the physical and chemical basis of life. Since our mental lives evidently depend on our existence as physical organisms, especially on the functioning of our central nervous systems, it seems natural to think that the physical sciences can in principle provide the basis for an explanation of the mental aspects of reality as well — that physics can aspire finally to be a theory of everything.

However, I believe this possibility is ruled out by the conditions that have defined the physical sciences from the beginning. The physical sciences can describe organisms like ourselves as parts of the objective spatio-temporal order – our structure and behavior in space and time – but they cannot describe the subjective experiences of such organisms or how the world appears to their different particular points of view. There can be a purely physical description of the neurophysiological processes that give rise to an experience, and also of the physical behavior that is typically associated with it, but such a description, however complete, will leave out the subjective essence of the experience – how it is from the point of view of its subject — without which it would not be a conscious experience at all. — Thomas Nagel, Core of Mind and Cosmos

No, Pinter does not try and explain the origin of mind. Wise choice, I think. — Wayfarer

So then, like Kant, his account of "noumenon" begs the question.

Don't miss the main point. — Wayfarer

You'll have to help me. I got this.

the world is 'mind-generated' - not the world in its entirety, not the whole vast universe of space and time, but 'world' as, and insofar as it is, a meaningful whole - which is the meaning of 'cosmos' - and in which the mind plays a fundamental part. — Wayfarer

These are great questions. I haven't read the thread, but I am a recovering Kant-thusiast. So take my answers for what you will....

Can Kant’s noumenal world to be understood to potentially have any kind of physical form (waves, for instance) which we cannot apprehend directly? Or is the use of the word ‘physical’ here entirely superfluous? — Tom Storm

I would say that Kant's noumenal world cannot have any kind of physical form, on pain of contradiction.

On that, though, I think Kant thinks action is the bridge between phenomenal reality and noumenal.

But what his actual philosophy says -- no. It's not possible.

Following Kant, we obviously construct the phenomenal world we know out of the noumenal world in some way - presumably from the sensations which present themselves to our consciousness. Is there any simple way of describing how this is might be understood to actually work?

If we follow Kant I don't think this is obvious -- I think it's an easy inference which makes sense of his writings, but it's not obvious. And I say it's not obvious because you're tripping across a conceptual bump Kant kind of didn't address, or at least tried to address and didn't satisfy.

If we are consistent with Kant's words, then we have no role in constructing a world out of the noumena. We construct phenomena.

In the phenomenal world we are always operating from some kind of sense making schema. We make sense of the world we apprehend and choices based on this - which may have impact upon our very survival (don’t jump off that cliff, don't smoke, etc). Could dying then be taken as an example of receiving direct feedback from the noumenal world?

Here I'd say yes, funnily enough. Mostly because Kant puts immortality (the soul) as one of the Ideas which are permanently sought after by Reason. A way of expressing Kant's thoughts on the soul are -- well, you won't know until you die. And then -- you'll either really really know in the same way you know you have a hand. Or won't exist at all. (basically saying the question is worthless to explore, on a scientific level of knowledge)

:up: In that case, you do get it. I just thought I might have distracted you from the main point of my review with that remark about the constitution of reason which is really outside the purview of Pinter's book (though obviously not of Kant!)

I'll have to check it out. Seems like similar conclusions to Hoffman's as far as the noumenal world is concerned, at least in that the reality of the 'view from nowhere' would be an objectless world, quite indescribable to us. One of the more interesting theories Hoffman had was that elements of how we perceive three dimensional space might be an artifact of an error correcting code used in perception. This might explain how we have observations supporting the Holographic Principal, but don't experience a two dimensional world, or at least it explains it more plausibly than some of the other ones I've heard.

I do think his arguments on how evolution shaped perception do a good job explaining why we insist on thinking about very small things as just paired down versions of the sorts of "medium sized objects" we have around us. We have evidence that some of our "deepest" measures of physical reality are subjective at heart (e.g., entropy re: the Gibbs Paradox), and this subjectivity flows from thinking about small objects as just being shrunk down large objects. For example, if haecceity is simply a property of the statistical tendency of very large collections of small things not to become completely indistinguishable from one another, then a great deal of how we measure potential microstates, the use of extensive formulas, is arbitrary and the result of how we evolved to deal with very large collections of "stuff," not how that stuff actually appears to work at the scales we are investigating. So, we also get non-extensive forms of entropy, Tsallis entropy, etc. and end up with situations where entropy is different if we know we have mixed two different gases than it is if we do not know this fact (i.e. subjective). But this seems like a problem when we are defining time using this same measure.

The main analogy used in Against Reality is that of a computer desktop screen. On a desktop, you see icons representing a trashcan you can drag files into. You rearrange files in folders. All this is completely unlike how the changes are actually processed within the computer, as adjustments of microscopic logic gates. We experience an email dragged into a trash can. We can also pull the email back out of the can. In reality, all that goes on is a very large number of changes in a few different types of logic gates relative to others. The idea is that our senses similarly provide us with a useful "desktop" interface. The "real world" might be as far from our sensory models as the electrical activity of a microprocessor is from dropping one file into another. In which case, a lot of our deep scientific problems might stem from the projection of the logic of our "desktop interfaces," into the world.

For Hoffman it is ludicrous to talk of "neurons giving rise to minds," as such because "neurons" only exist in the minds of human beings. Our idea of neurons might have some relation to the noumenal, but it is by no means very direct.

Having read Becker's What is Real? on quantum foundations just before The Case Against Reality, I found this to be more reasonable than I might have before. After all, we have this huge issue of an arbitrary classical/quantum divide hanging over our sciences that seems less and less supportable. We also have all sorts of holes that have emerged in the conventional model of relativistic space-time, such that space-time looks to be in similar shape to Newtonian space and time circa the later 19th century (i.e. ready for replacement).

We know our laws are just gross approximations. Newton's Laws don't actually describe how physics works, they describe an idealized system with only two bodies, where those bodies do not have composite parts and are in isolation. The issue is that we mistake predictive power and usefulness for veracity, which is falling into the very same trick as when we assume our senses must report the world "as it is," because they are useful. But selection for usefulness is a different criteria than selection for truth.

Indeed, in Deacon's Steps to A Science of Biosemiotics its pointed out that life has to filter out truth, as actual representations of the truth would entail bringing in so much entropy into the organism that it would dissolve.

My own personal view is that the 'view from nowhere" or "God's eye view" is a sort of demon haunting the sciences. It makes no sense in the context of our physics. Things only have and exchange information in relation to other things. We need descriptions that have this baked into the cake. A thing is what it is for something else. Fichte was totally right to write off the "thing in itself," as nonsense.

We also need to recognize that, within a single phenomena we want to examine, a thing might fit into any of the three points of a semiotic triangle. Vision might have the object seen as the referent, the patterns of photoreceptor activation sent down the optic nerve as symbol, and the brain as interpretant. But within the context of the entire phenomena it may be that a pattern of neuronal activation in one region of the brain is the referent, the symbol is another pattern of activation within neurons connecting the referent area to another processing area, and the interpretant is this new processing area, which may itself be a symbol or referent in another set of parallel relationships. These relationships, and the definition of systems themselves, are necessarily arbitrary subjective abstractions. That's fine, it turns out entropy is too. It will still pay to have a way to formalize these subjective relationships somehow.

Information, when defined as the "difference that makes a difference," changes in context. Objects that may be synonyms in one type of relationship might be distinct in another.



I feel like this is sort of inevitable. You have to assume the noumenal exists from the outset. Otherwise you can always just see science as a description of how mental objects interact. You can't fully exorcise radical skepticism, but plenty of good works have been done to talk people down off the ledge of skepticism (the Phenomenology of Spirit being the example I always look to).

Kastrupt's Idea of the World, while advancing a less than convincing idealist ontology, has a very succinct overview of the seemingly intractable problems facing realism and particularly physicalism. But the interesting thing to me is that the same arguments he uses can be easily flipped around to show how, assuming that physicalism is true, we would still have these same intractable issues anyhow.

Science will always have a problem explaining the characteristics of subjective experience because you're asking a set of abstractions that exist as a subset of the world of experience to explain all of experience. Its asking something ontologically derivative to explain its ontological primitive. However, it would seem to hold that this would be a problem even if physicalism were the case, so in a way it's a helpful explanation of physicslism's apparent failings and only damaging to certain formulations of naive realism.

This seems like a real benefit. Parts of the Hard Problem can be chalked up to the same sorts of epistemological issues that keep solipsism and radical skepticism viable. This I find far more convincing than arguments that try to tell you that experience isn't actually real to deal with the issue, which always seemed like a giant bait and switch to me.

Kastrupt's Idea of the World, while advancing a less than convincing idealist ontology, has a very succinct overview of the seemingly intractable problems facing realism and particularly physicalism. But the interesting thing to me is that the same arguments he uses can be easily flipped around to show how, assuming that physicalism is true, we would still have these same intractable issues anyhow. — Count Timothy von Icarus

Can you say a little more? Why do you find Kastrup's Analytic Idealism less than convincing? I ask out of interest, and am personally not invested in his ontology.

You have to assume the noumenal exists from the outset [ ... ] You can't fully exorcise radical skepticism, but plenty of good works have been done to talk people down off the ledge of skepticism (the Phenomenology of Spirit being the example I always look to). — Count Timothy von Icarus

I don't think so. Hegel completely rejects Kant's noumenon / thing-in-itself – he doesn't "have to assume" it and neither do we (pace Schopenhauer).

Yeah, bit of a red herring on my part. I mentioned the Phenomenology only because it's a good work arguing against radical skepticism. I see the two things (moving past radical skepticism and adopting realism) as somewhat related in that I don't think there is a way to resolve all objections to them completely to anyone's satisfaction based on logic alone. Decarte's Demon could always be feeding you any evidence you think you get from experience, there is no way to rule that out (or to totally rule out Hume's arguments against induction, same sort of issue), but there are obviously benefits to moving on from that place of skepticism.



I thought it was unconvincing because the explanation of how there can be multiple minds within a larger, universe sized-mind seemed fairly ad hoc. He uses disassociative disorders and multiple personality disorders as the model for his explanation and there just doesn't seem to be any reason to think this big ontologically basic mind would reflect these disorders.

Then he has living things as being the possessors of these disassociated minds. He then claims that AI will never be minded because minds are unique to things that are alive. But the line between living and nonliving is not clearly defined today, so this seems fairly fuzzy at best, open to an argument along the lines of Hemple's Dilemma at worst.

These two parts seemed quite ad hoc to me.

Edit: I should note, this was "The Idea of the World," I haven't read his others.

For Hoffman it is ludicrous to talk of "neurons giving rise to minds," as such because "neurons" only exist in the minds of human beings. — Count Timothy von Icarus

That's an argument I've pursued on this forum myself. The entire problem with physicalism is the meaning of causation or 'giving rise to' when proposing a causal relationship between the brain and the mind, even though it is so widely assumed as an obvious truth. Kastrup puts it like this:

qualities have no function under materialism, for quantitatively-defined physical models are supposed to be causally-closed; that is, sufficient to explain every natural phenomenon. As such, it must make no difference to the survival fitness of an organism whether the data processing taking place in its brain is accompanied by experience or not: whatever the case, the processing will produce the same effects; the organism will behave in exactly the same way and stand exactly the same chance to survive and reproduce. Qualia are, at best, superfluous extras.

Therefore, under materialist premises, phenomenal consciousness cannot have been favoured by natural selection. Indeed, it shouldn’t exist at all; we should all be unconscious zombies, going about our business in exactly the same way we actually do, but without an accompanying inner life. If evolution is true—which we have every reason to believe is the case—our very sentience contradicts materialism. — Bernard Kastrup, Consciousness Cannot have Evolved (paywalled)

Which is precisely why Dennett wants to eliminate it ;-) (And actually, there's a connection between that insight, and the 'argument from reason', which likewise argues that to reduce reason to an evolutionary adaptation is to undermine its sovereignty.)

I read Adam Becker's book also, but I thought it got tangled in the weeds towards the end - longing for a realist conclusion which is not there to be found. Manjit Kumar's book Quantum is better IMO. I'm also impressed by QBism, which Pinter mentions.

Charles Pinter's book is an unsung classic in my view. I think it helps that he's outside academic philosophy - he's a mathematician with a long interest in neural modelling. But it's a model of clarity and conciseness and I recommend it.

A major theme of this book is that “reality” is not confined to matter and its physical properties. There is a whole firmament of appearances, sensations, perceptions, insights and wide-ranging Gestalt vision. These things exist in the minds of sentient creatures, and are often won by hard and persistent effort. It is true that they exist only in animal minds, but they are nonetheless real and indispensable aspects of the universe. What is shown above is that the very existence of hierarchically complex objects is confined to the minds of living observers. Only living minds apprehend complexity and multiplicity. Complexity exists in the universe solely because it is discerned—in fact created—in minds. It exists only in minds.

Pinter, Charles. Mind and the Cosmic Order (pp. 86-88). Springer International Publishing. Kindle Edition.

The problem I find with Hoffmann's theory is that if reality were nothing like what we experience, then how could he justifiably arrive at the conclusion that reality is nothing like what we experience?

He has studied evolution, game theory, brains and so on to arrive at his theory; but then according to his theory evolution, game theory and brains cannot be anything like what and how we think they are, which, if accepted, seems to lead inexorably to the conclusion that his theory is completely without ground.

The problem I find with Hoffmann's theory is that if reality is nothing like what we experience, then how could he arrive at the conclusion that reality is nothing like what we experience. — Janus

Through reason and experimental observation. He calls his theory 'conscious realism' - objective reality is something in the minds of conscious agents. But because we're all immersed in the same milieu, the experiences of those agents will sync to a very high degree. It there a reality 'outside of' or 'apart from' that? Well, how could you tell? You can't stand outside your own cognitive apparatus to determine that.

The idea that what we’re doing is measuring publicly accessible objects, the idea that objectivity results from the fact that you and I can measure the same object in the exact same situation and get the same results — it’s very clear from quantum mechanics that that idea has to go. Physics tells us that there are no public physical objects. So what’s going on? Here’s how I think about it. I can talk to you about my headache and believe that I am communicating effectively with you, because you’ve had your own headaches. The same thing is true as apples and the moon and the sun and the universe. Just like you have your own headache, you have your own moon. But I assume it’s relevantly similar to mine. That’s an assumption that could be false, but that’s the source of my communication, and that’s the best we can do in terms of public physical objects and objective science. — Donald Hoffman

That is compatible with QBism (not to mention a lot of the ideas that Apokrisis brings in).

QBism would say, it’s not that the world is built up from stuff on “the outside” as the Greeks would have had it. Nor is it built up from stuff on “the inside” as the idealists, like George Berkeley and Eddington, would have it. Rather, the stuff of the world is in the character of what each of us encounters every living moment — stuff that is neither inside nor outside, but prior to the very notion of a cut between the two at all. — Chris Fuchs

Which is also what Charles Pinter is saying.

(It's also what I've tried to say many times over the years in saying that reality has a subjective pole or element that is not noticed or hidden, which for some reason you kept insisting was obvious.)

These two parts seemed quite ad hoc to me. — Count Timothy von Icarus

Thanks for the clarification. I hear you.

Through reason and experimental observation. — Wayfarer

But if reality were nothing like what we experience, no kind of observation would be telling us anything that we could justifiably base any theory on. For example the idea of evolution is based on the fossil record; and observation of plants and animals and their similarities and differences, and also on studying DNA profiles but according to his theory all that could tell us nothing about how species evolved, and indeed the very idea of species evolving and sharing traits and DNA would be groundless.How do you think he could address this problem?

But if reality were nothing like what we experience, — Janus

He's not saying that. I don't think you've taken in what he's saying. I would say (although he doesn't say) that what he and Chris Fuchs are both calling into question is the assumption of a mind-independent reality.

He's not saying that. I don't think you've taken in what he's saying. — Wayfarer

What do you think he's saying?

The same thing is true as apples and the moon and the sun and the universe. Just like you have your own headache, you have your own moon. But I assume it’s relevantly similar to mine. That’s an assumption that could be false, but that’s the source of my communication, and that’s the best we can do in terms of public physical objects and objective science. — Donald Hoffman

So, if it were true that your apple is nothing like mine. leaving aside the fact that we can both reliably point to the apple and agree that it is an apple, we can also agree about it's colour and unique features. Say it's a red apple with three yellow spots and I point to where I see the yellow spots and ask you what you see there. I would wager my house that you would say you see three yellow spots. How would Hoffmann explain that, if the apple you see and the apple I see were not "relevantly similar"?

The idea that what we’re doing is measuring publicly accessible objects, the idea that objectivity results from the fact that you and I can measure the same object in the exact same situation and get the same results — it’s very clear from quantum mechanics that that idea has to go. Physics tells us that there are no public physical objects. So what’s going on? Here’s how I think about it. I can talk to you about my headache and believe that I am communicating effectively with you, because you’ve had your own headaches. The same thing is true as apples and the moon and the sun and the universe. Just like you have your own headache, you have your own moon. But I assume it’s relevantly similar to mine. That’s an assumption that could be false, but that’s the source of my communication, and that’s the best we can do in terms of public physical objects and objective science. — Donald Hoffman

Reality is not 'just an experience'. It's a constructive activity which synthesises elements of sensory data with the categories of the understanding to generate the phenomenal experience. What's being called into question is the existence of what is purportedly 'outside of' or 'independent of' those gestalts.

For example the idea of evolution is based on the fossil record; and observation of plants and animals and their similarities and differences, and also on studying DNA profiles but according to his theory all that could tell us nothing about how species evolved, and indeed the very idea of species evolving and sharing traits and DNA would be groundless.How do you think he could address this problem? — Janus

Kastrup (a different idealist thinker) simply argues that all we experience is real - it just isn't physical. So signs and fossils and DNA and an oncoming bus - are all important readings on a dashboard that hold real consequences. They are mind when observed from a different perspective. But this stuff is very elusive and cannot be demonstrated other than undermining materialist ontologies.

Reality is not 'just an experience'. It's a constructive activity which synthesises elements of sensory data with the categories of the understanding to generate the phenomenal experience. — Wayfarer

The interesting part of this for me is unpacking what these 'categories of understanding' are. Not wanting to race ahead but I am assuming that here you would subscribe to a Platonist model of ideas, right?