But can’t you see that the same principle applies to all empirical facts? Not simply what existed prior to human life, but anything that happened in the past. From a naturalistic perspective, of course there’s a temporal sequence within which the human species is a recent arrival (‘a mere blip’, as if often said). — Wayfarer

Please indulge me and answer the questions. Is it false that there was a moving asteriod before humans?

It’s not false, but I feel the question is being asked for a reason over and above its facticity, namely, by way of introducing a naturalist philosophy of mind.

↪fdrake It’s not false, but I feel the question is being asked for a reason over and above its facticity, namely, by way of introducing a naturalist philosophy of mind. — Wayfarer

Do you agree that the fact entails that there was space before human minds? Because it had to move in space to move. It's an asteroid.

I take it you don't know if you can conceive of a world without mind or consciousness.

I take it you don't know if you can conceive of a world without mind or consciousness. — frank

The problem with this question is a world without mind or consciousness would be a world in which you did not have mind or consciousness, in which case it is obvious that you could not conceive it.

But this should not be taken to mean that there is anything that prohibits a world without mind or consciousness. That there is mind or consciousness does not mean that there must be mind or consciousness or that there cannot be a world without mind or consciousness.

The problem with this question is a world without mind or consciousness would be a world in which you did not have mind or consciousness, in which case it is obvious that you could not conceive it. — Fooloso4

I guess I phrased that poorly. Can you conceive of a world that is devoid of consciousness? One in which there is no consciousness?

I don't think Wayfarer was going to answer it however I phrased it, tho. :)

Are you a panpsychist? — frank

I see panpsychism as a kind of pseudo-scientific claim - that consciousness (actually I prefer ‘mind’) exists as an attribute or potential within any and every object. But this doesn’t come to terms with the meaning of the ‘process of objectification’.

Do you agree that the fact entails that there was space before human minds? Because it had to move in space to move. It's an asteroid. — fdrake

All due respect, we’re talking past each other.

All due respect, we’re talking past each other. — Wayfarer

If you say my argument is question begging, and I've made it into something like a syllogism, you should be able to tell me precisely in what premise or inference I'm begging the question. If it's not in premise (1), I've moved onto premise (2). So I'll ask again:

Do you agree that the fact entails that there was space before human minds? Because it had to move in space to move as asteroids do.

Premise (1) begs the question. The existence of "an asteroid" assumes the human spatial-temporal perspective which individuates and identifies something as "an asteroid". Therefore it is really impossible that there was such a thing as an asteroid before humans, because it requires a human to identify a thing as "an asteroid" in order that there is such a thing as an asteroid. Unless you believe that God identified things, and called them "asteroids" before there were human beings, there was no such thing as "an asteroid" before there were humans beings.

It depends on what is meant by saying that prior to humans there were asteroids. Something extra-mental (at least in the sense of 'beyond' or 'outside' the human mind) is obviously involved in producing the human experience of a world of phenomena (including asteroids), and it seems safe to at least entertain the idea that that "extramental something" pre-existed humans.

So, if by saying there were asteroids all that is meant is that whatever it is (apart from the human itself) that produces the human experience of asteroids pre-existed humans, then there would seem to be no problem. As I have said before, saying there were asteroids prior to humans just means that if we had been there we would have seen asteroids.

What I’m arguing is that time itself, the sequential ordering of events along a specific scale, is grounded in the mind. That’s the import of the passage I quoted from Paul Davies:

"The passage of time is not absolute; it always involves a change of one physical system relative to another, for example, how many times the hands of the clock go around relative to the rotation of the Earth. When it comes to the Universe as a whole, time loses its meaning, for there is nothing else relative to which the universe may be said to change. This 'vanishing' of time for the entire universe becomes very explicit in quantum cosmology, where the time variable simply drops out of the quantum description. It may readily be restored by considering the Universe to be separated into two subsystems: an observer with a clock, and the rest of the Universe. So the observer plays an absolutely crucial role in this respect. Linde expresses it graphically: 'thus we see that without introducing an observer, we have a dead universe, which does not evolve in time', and, 'we are together, the Universe and us. The moment you say the Universe exists without any observers, I cannot make any sense out of that. I cannot imagine a consistent theory of everything that ignores consciousness...in the absence of observers, our universe is dead'." — Wayfarer

Davies is referring to the world, not mind, when he says, "... how many times the hands of the clock go around relative to the rotation of the Earth."

The only reference to mind or consciousness is Linde's claim in the second-last line, but that doesn't follow from anything he or Davies said in that passage, the import of which is that time is reference-frame dependent. That is, time does not apply to the universe as a whole, it applies to subsystems.

For an explanation of how time vanishes for the universe as a whole, see Quantum Experiment Shows How Time ‘Emerges’ from Entanglement.

Davies is referring to the world, not mind — Andrew M

He explicitly states ‘an observer with a clock’.

He explicitly states ‘an observer with a clock’. — Wayfarer

In a physics context, an observer is "a frame of reference from which a set of objects or events are being measured", not a reference to mind.

It's useful to separate the idea of the reference frame of a system from the idea of the consciousness of a system. Time is reference frame-dependent, not mind-dependent. Which is why it is coherent to say that the Earth aged prior to the existence of human beings.

n a physics context, an observer is "a frame of reference from which a set of objects or events are being measured", not a reference to mind. — Andrew M

Definitions that are created by physicists. And measurement is a conscious process.

Scale and perspective likewise imply a point of view, because you can’t have either without a comparison.

Recall that we’re speaking about ‘things as they appear to us’, not ‘things as they are in themselves.’ That is the fundamental point in this conversation.

It’s not false, but I feel the question is being asked for a reason over and above its facticity, namely, by way of introducing a naturalist philosophy of mind. — Wayfarer

I'm puzzled as to why you detest naturalistic philosophies of mind so much! Is it because you feel they threaten your religious faith? I don't see why that should be.

You have said before that if reason is evolved then it is undermined. I don't buy this. In fact Hegel sees reason as evolving, and sees the real as being intrinsically rational. On this account logic would be expected to evolve and perfect itself via the "practice" of sensory experience most broadly conceived. Reason and logic are not bloodless transparencies.

Definitions that are created by physicists. — Wayfarer

You were quoting physicists as supporting your argument.

And measurement is a conscious process.

Scale and perspective likewise imply a point of view, because you can’t have either without a comparison.

Recall that we’re speaking about ‘things as they appear to us’, not ‘things as they are in themselves.’ That is the fundamental point in this conversation. — Wayfarer

So the Earth appears to be 4.5 billion years old but isn't really?

The human point-of-view is a relational one (i.e., between natural systems, of which a human is one) and does not depend on a Kantian phenomenal/noumenal distinction.

Do you agree that the fact Reveal entails that there was space before human minds? Because it had to move in space to move as asteroids do. — fdrake

The problem is that you’re answering a philosophical question about the nature of knowledge with a scientific question based on the knowledge of nature. That's why we're talking past one another. (I've now answered AndrewM below about a similar point.)

I'm puzzled as to why you detest naturalistic philosophies of mind so much! Is it because you feel they threaten your religious faith? — Janus

I don't 'detest' them, and I try not to engage in inflammatory language; I criticize them.

Hegel sees reason as evolving, — Janus

But Hegel is hardly representative of modern evolutionary thinking or even current philosophy for that matter. Tielhard du Chardin and Henri Bergson are others who interpreted evolution philosophically, but they are generally ignored; outside places like philosophy forums you'd hardly hear of them. (For that matter, Alfred Russel Wallace differed completely with Darwin on the question of the evolution of h. sapiens, on similar grounds.)

My view is humans obviously evolved according to the outlines of evolutionary theory but that once the evolved to the point of language- and tool-using beings, they are able to 'transcend the biological', as it were. But because evolutionary theory stands in as a kind of secular creation theory, then all kinds of conclusions are read into it which are beyond its scope. Chief amongst them is that language and reason have a kind of Darwinian rationale, that they can be understood in the same terms as other adaptations (Dawkins says somewhere that language is like 'a fantastic peacock's tail' i.e. superb for propagating the genome). It's simply taken for granted, it's what everyone knows, or thinks they know.

So the Earth appears to be 4.5 billion years old but isn't really? — Andrew M

Kant, as we may recall, professed to be both an empirical realist, AND a transcendental idealist. He himself was well versed in the cosmological science of his day and in fact his theory of nebular formation, adapted by LaPlace, is still part of astronomical theory to this day.

So how could he be both? Because the 'transcendental idealist' perspective is about the grounds of the possibility of knowledge itself. It is not about natural phenomena, but about the nature of our understanding, of how 'nature' is known to us (i.e. as phenomena) and how we must necessarily understand appearances in accordance with the apparatus of the understanding. This is the basis of his well-known Copernican revolution in philosophy, that 'things conform to thoughts, not thoughts to things'.

So how does this bear on the age of the universe? It is an empirical fact (unless of course disproven by some other discovery.) Whereas, what I have been debating with fdrake goes back to:

Nature doesn't turn on human understanding, surely you can understand that. This fact alone, and our capacity to understand it, should perturb us away from any attempt to derive the ontology of this indifferent, inhuman nature, from the a priori structures of our experiences. — fdrake

The difficult philosophical issue here is the relationship between temporal and logical priority. The planet, living systems, and h. sapiens plainly evolved along the lines somewhat understood by science (again pending further discoveries). But I'm taking issue with the notion that the nature of reason herself - the a priori and necessary truths, and so on - can be understood along those lines. I believe that fdrake, along with the majority, believe that reason (etc) is an evolved capacity, and therefore can be understood naturalistically along those lines. To try and come to a point, this is the mainstream view of evolutionary naturalism, which is the subject of criticism in Nagel's book, Mind and Cosmos. (I say that, because it's a long and very acrimonious debate between a lot of heavyweights, and I don't have time to try and spell out all the intricacies.)

But, suffice to say, that I still believe that human beings are ultimately not simply reducible to biological or any other purely physical causes. We have a biological side, but what ultimately what our real nature is, is not something known to the objective or physical sciences, because it transcends them. The philosophical argument for that, is that logical and arithmetical truths transcend contingent facts; that's why, in Greek philosophy, you had the idea of the 'rational soul', which is that man, by the power of reason, could realise his identity as something 'transcending the biological' (which was ultimately merged, with uneven results, into Christian eschatology. It's tremendously non-PC nowadays, but fortunately, I'm only an amateur on a forum, not an academic having to defend such an outrageous idea in the Secular Academy.)

The human point-of-view is a relational one (i.e., between natural systems, of which a human is one) and does not depend on a Kantian phenomenal/noumenal distinction. — Andrew M

That distinction doesn't require the blessing of naturalism.

It depends on what is meant by saying that prior to humans there were asteroids. Something extra-mental (at least in the sense of 'beyond' or 'outside' the human mind) is obviously involved in producing the human experience of a world of phenomena (including asteroids), and it seems safe to at least entertain the idea that that "extramental something" pre-existed humans. — Janus

So it doesn't make sense to say that there were things called "asteroids" at that time, does it?

So, if by saying there were asteroids all that is meant is that whatever it is (apart from the human itself) that produces the human experience of asteroids pre-existed humans, then there would seem to be no problem. — Janus

This is blatantly false in two distinct ways. First, it is the human being with its many systems, which produces the experience of an asteroid. I agree that there is something "extra" involved, but it is incorrect to say that this extra thing is what produces the experience. That's what separates the position I'm arguing from the brain in a vat scenario. The brain in the vat requires the evil genius to "produce" the experience, I argue that the brain produces the experience. I accept, on the basis of evidence, that there is something extra, but the extra thing is not necessary, therefore we cannot say that it is the cause of experience.

Second, if we assume the reality of this "extra" thing, the first thing that is evident about it, is that what exists at one time is distinctly different from what exists at another time. Whatever it is, that "extra" thing, which might contribute to a human experience of a asteroid today, or might have contributed to an experience yesterday, was not the same before human existence. So you have a faulty assumption of continuity, "sameness", which does not account for the reality of change. You need some principles to base this idea, that the same "extra" thing which contributes to a human experience existed prior to human beings, when the evidence indicates that we live in a world of change.

The problem is that you’re answering a philosophical question about the nature of knowledge with a scientific question based on the knowledge of nature. That's why we're talking past one another. (I've now answered AndrewM below about a similar point.) — Wayfarer

Do you agree that the (existence of a moving asteroid prior to the existence of humans) entails that there was space before human minds? Because it had to move in space to move as asteroids do.

Edit: you are absolutely fine leveraging scientific thinking whenever it serves your perspective, and I won't let you subject me to this double standard.

My view is humans obviously evolved according to the outlines of evolutionary theory but that once the evolved to the point of language- and tool-using beings, they are able to 'transcend the biological', as it were. — Wayfarer

So humans did evolve from animal precursors? And this evolution occurred prior to the advent of the consciousness and reason that, according to you, constructs empirical reality?

First, it is the human being with its many systems, which produces the experience of an asteroid. I agree that there is something "extra" involved, but it is incorrect to say that this extra thing is what produces the experience. — Metaphysician Undercover

There is no experience of the asteroid without the asteroid, and the light that reflects from the surface of the asteroid that enables us to see it. In fact it is the conditions of the world, taken as a whole, including the human, that produces the experience of the asteroid, so the "something else" that produces the experience of an asteroid is nothing less than the whole world.

The problem is that you’re answering a philosophical question about the nature of knowledge with a scientific question based on the knowledge of nature. That's why we're talking past one another. (I've now answered AndrewM below about a similar point.) — Wayfarer

The problem is that you're giving two contrary answers to the same question. :-) You seem to be saying that space and time existed in a scientific sense prior to humans, but not in a philosophical sense.

So how could he be both? Because the 'transcendental idealist' perspective is about the grounds of the possibility of knowledge itself. It is not about natural phenomena, but about the nature of our understanding, of how 'nature' is known to us (i.e. as phenomena) and how we must necessarily understand appearances in accordance with the apparatus of the understanding. This is the basis of his well-known Copernican revolution in philosophy, that 'things conform to thoughts, not thoughts to things'. — Wayfarer

So the Earth conforms to thoughts of the Earth? If so, does that imply that without humans there would be no Earth?

The human point-of-view is a relational one (i.e., between natural systems, of which a human is one) and does not depend on a Kantian phenomenal/noumenal distinction.
— Andrew M

That distinction doesn't require the blessing of naturalism. — Wayfarer

Understandably, since the Kantian distinction opposes a natural epistemology. The natural distinction is, for example, that there can be a straight stick that appears bent in water. The Kantian distinction is that the straight stick is itself "an appearance" and not what the stick is "in itself".

I may be mistaken, but I think this shows an inaccurate understanding of Kant.

The Kantian distinction is that the straight stick is itself "an appearance" and not what the stick is "in itself". — Andrew M

This is not at all true - Berkeley addresses the same point, and Kant in much greater detail. What Kant means by 'phenomenon' or 'appearance' is not mere phenomenon or mere appearance.

You seem to be saying that space and time existed in a scientific sense prior to humans, but not in a philosophical sense. — Andrew M

Empirically, it is obviously true, but the philosophical analysis is about how we know this (or anything!) to be true. Don't forget, philosophy is concerned with the nature of knowledge, the ground of knowledge, in a way that science is not. Naturalism assumes that the natural order is consistent and existent. A passage on Quine puts it like this:

“Abandonment of the goal of a first philosophy. [Naturalism] sees natural science as an inquiry into reality, fallible and corrigible but not answerable to any supra-scientific tribunal, and not in need of any justification beyond observation and the hypothetico-deductive method” (Quine 1981: 72).

Quine's naturalism was developed in large part as a response to positivism. Positivism requires that any justified belief be constructed out of, and be reducible to, claims about observable phenomena. We know about ordinary objects like trees because we have sense experience, or sense data, of trees directly. We know about very small or very distant objects, despite having no direct sense experience of them, by having sense data of their effects, say electron trails in a cloud chamber. For the positivists, any scientific claim must be reducible to sense data.

Instead of starting with sense data and reconstructing a world of trees and persons, Quine assumes that ordinary objects exist.

But it's just that assumption which has been called into question by physics - that's why all of the controversy about the 'observer problem'. The many-worlds interpretation, which I believe you endorse, was only thought of as a solution to that problem, so it's some problem!

It's also called into question by philosophy. When we 'see the tree', what's actually going on? There's no 'light inside the skull'. The brain constructs the image on the basis of received sense-data combined with judgement; this is what's really happening. But when naturalism eschews 'first philosophy' it 'brackets out' all those considerations and says, more or less, 'let's start with what is "really there" '. And in doing that, the critical project of philosophy has been abandoned. Or, essentially, we're equating science with metaphysics.

Speaking of positivism, Bohr's well-known saying 'If you're not shocked by quantum physics, then you can't have understood it', was a statement made after he had given a talk to the Vienna Circle positivists. After hearing him, they all seemed positively sanguine - and that's what he said!

If so, does that imply that without humans there would be no Earth? — Andrew M

It's not so simple as that. It's about judgements of what is real, of the ground of the understanding. I know it's perplexing, baffling and an apparent outrage to common sense but I have good reason to argue it. (Actually, in this context, I've learned a lot from Buddhist philosophy of 'mind-only' and 'emptiness', which provide an interpretive framework within which these ideas make sense.)

There is no experience of the asteroid without the asteroid.. — Janus

But this is false. There could be an hallucination in which there is an experience of an asteroid, in which case there is the experience of that asteroid, the imaginary asteroid. Therefore there is the experience of the asteroid (the fictional asteroid) without any real physical asteroid. And this is not a small problem to be dismissed as nonsense, because in particle physics there are no real fundamental particles. There is something which is experienced, and the name "particle" is given to that experience, but there are no actual physical particles. So there is the experience of particles without any real physical particles.

In fact it is the conditions of the world, taken as a whole, including the human, that produces the experience of the asteroid, so the "something else" that produces the experience of an asteroid is nothing less than the whole world. — Janus

How would you account for imagination and creativity then? Suppose that someone creates a tune, and hums it in one's mind, or someone creates an image of a fictional asteroid, or a physicist creates a fictional particle. Why would you say that "the whole world" produces this experience when it's really just the imagination of the creator? .

There could be an hallucination in which there is an experience of an asteroid — Metaphysician Undercover

A mass hallucination of an asteroid is a highly dubious proposition to say the least.

Why would it have to be a mass hallucination? if one person hallucinates an asteroid, then that person can speak about that asteroid.

Hallucinating an asteroid is not seeing an asteroid.

We weren't talking about seeing an asteroid, we were talking about experiencing an asteroid, and what it is which "produces" the experience. I think that it is the systems within the human being which produce the experience, though I agreed that there is something "extra " involved with the experience. But you were claiming that the extra thing produces the experience. That, I think is clearly false.

The point is that there is no direct chain of causation between the thing within the experience, and the sensible "extra" thing which you claim produces the experience, so it is false to say that the sensible thing produces the experience. In reality, the causal chain which produces the experience occurs within the human being, and the things which are sensed act as influences on this experience. This is evident in the reality of hallucinations, dreams, and imagination. You cannot just dismiss the reality of these experiences for the sake of supporting your claim that the sensible "extra" thing produces the experience. Then suggest that we were discussing "seeing" rather than "experiencing".

Consider for example, the experience of hearing someone play the piano. What you hear is a series of notes and chords, music. If you look, with your eyes, you see someone playing the piano, and the person's actions correspond with what you hear. Because of this temporal correspondence, between what you hear and what you see, you might conclude that the person's actions at the piano are causing you to hear music. But you'd be forgetting the role that the human body plays in selecting a very specific and minute part of the vast reality around it, the notes, and focusing on that very tiny aspect, to hear the music independent of sights, smells etc., and even other sounds. Likewise, when you look with your eyes, you must focus on a very tiny aspect of the vast environment, to see that it is the particular actions of the person at the piano which correspond to what you hear.

So it really is the human body which produces the experience, through a process of selecting from what is available in the environment. Each sense is designed to distinguish a very unique type of information, indicating that the body has developed ways of separating out, and focusing in on very tiny aspects of a vast world, creating an "experience" through this process of separating things from each other. The experience is created by this process of separating things out, which the senses do, distinguishing minute parts, along with the brain synthesizing all this distinct information into a unity. The "experience" is the unity, and this unity is synthetic, produced within the body, with information selected by the body..

↪Andrew M I may be mistaken, but I think this shows an inaccurate understanding of Kant.

The Kantian distinction is that the straight stick is itself "an appearance" and not what the stick is "in itself".
— Andrew M

This is not at all true - Berkeley addresses the same point, and Kant in much greater detail. What Kant means by 'phenomenon' or 'appearance' is not mere phenomenon or mere appearance. — Wayfarer

I'd be keen to get to the bottom of this. From the SEP entry on Kant’s Transcendental Idealism, 'Objects in space and time are said to be "appearances", and [Kant] argues that we know nothing of substance about the things in themselves of which they are appearances.'

That is, according to Kant, the straight stick is an appearance and the things in themselves that give rise to the appearance of the straight stick are unknowable.

If you don't think that's right, how would you (briefly) characterize Kant's phenomena/noumena distinction?

" “Abandonment of the goal of a first philosophy. [Naturalism] sees natural science as an inquiry into reality, fallible and corrigible but not answerable to any supra-scientific tribunal, and not in need of any justification beyond observation and the hypothetico-deductive method” (Quine 1981: 72).
...
Instead of starting with sense data and reconstructing a world of trees and persons, Quine assumes that ordinary objects exist." [A passage on Quine] — Wayfarer

I agree with Quine about ordinary objects (and the rejection of sense data and positivism), but would put the inquiry issue like this: While physics is the study of nature, metaphysics is the study of the study of nature (which is itself a part of nature). So a natural metaphysics is reflective in a way that operational physics is not.

But it's just that assumption which has been called into question by physics - that's why all of the controversy about the 'observer problem'. — Wayfarer

What has been called into question by physics is an implicit assumption about ordinary objects, termed counterfactual definiteness. No interpretation denies that trees and persons exist.

It's also called into question by philosophy. When we 'see the tree', what's actually going on? There's no 'light inside the skull'. The brain constructs the image on the basis of received sense-data combined with judgement; this is what's really happening. But when naturalism eschews 'first philosophy' it 'brackets out' all those considerations and says, more or less, 'let's start with what is "really there" '. And in doing that, the critical project of philosophy has been abandoned. Or, essentially, we're equating science with metaphysics. — Wayfarer

The phrase 'see the tree' is a language abstraction and implies nothing about the underlying natural processes. The role of science is to investigate the objects and processes involved. The role of philosophy is to sort out the conceptual problems that arise (such as 'light in skulls' and 'sense-data').

It's not so simple as that. It's about judgements of what is real, of the ground of the understanding. I know it's perplexing, baffling and an apparent outrage to common sense but I have good reason to argue it. (Actually, in this context, I've learned a lot from Buddhist philosophy of 'mind-only' and 'emptiness', which provide an interpretive framework within which these ideas make sense.) — Wayfarer

Equally, I know that positing the reality of ordinary objects is perplexing, baffling and an apparent outrage to philosophical sensibilities but I have good reason to argue it. ;-) Observation and reflection on the natural world provides an interpretive framework within which these ideas make sense.

We weren't talking about seeing an asteroid, we were talking about experiencing an asteroid, and what it is which "produces" the experience. — Metaphysician Undercover

The logic is the same with either "seeing" or "experiencing".Hallucinating an asteroid is not experiencing an asteroid, but experiencing an hallucination. If an asteroid is experienced then it follows that the asteroid plays an essential part in producing that experience. The logic here is irrefutable.

I'd be keen to get to the bottom of this. From the SEP entry on Kant’s Transcendental Idealism, 'Objects in space and time are said to be "appearances", and [Kant] argues that we know nothing of substance about the things in themselves of which they are appearances.'

That is, according to Kant, the straight stick is an appearance and the things in themselves that give rise to the appearance of the straight stick are unknowable.

If you don't think that's right, how would you (briefly) characterize Kant's phenomena/noumena distinction? — Andrew M

Hasty answer as I'm on duty.

Note that the optical illusion example is often thrown at Berkeley, but he does have an answer to it.

Say we see an oar in water, Hylas says, and it appears bent to us. We then lift it out and see that it is really straight; the bent appearance was an illusion caused by the water's refraction. On Philonous' view, though, we cannot say that we were wrong about the initial judgement; if we perceived the stick as bent then the stick had to have been bent. Similarly, since we see the moon's surface as smooth we cannot really say that the moon's surface is not smooth; the way that it appears to us has to be the way it is.

Philonous has an answer to this worry as well. While we cannot be wrong about the particular idea, he explains, we can still be wrong in our judgement. Ideas occur in regular patterns, and it is these coherent and regular sensations that make up real things, not just the independent ideas of each isolated sensation. The bent stick can be called an illusion, therefore, because that sensation is not coherently and regularly connected to the others. If we pull the stick out of the water, or we reach down and touch the stick, we will get a sensation of a straight stick. It is this coherent pattern of sensations that makes the stick. If we judge that the stick is bent, therefore, then we have made the wrong judgement, because we have judged incorrectly about what sensation we will have when we touch the stick or when we remove it from the water.

Over and above that - after the first edition of CPR was published, many critics said Kant was simply repeating Berkeley. So in the preface to the second edition contained his 'critique of material idealism' aimed at Berkeley (which you can find an account of here).

My interpretation is as follows: to say that we have knowledge of only of phenomena is not to say we know nothing, as pragmatically speaking, the phenomenal domain exhibits all of the regularities and consistencies which natural science observes. So when I said 'not mere appearance', I'm saying that Kant doesn't regard the appearance of phenomena as a mere trifle or an optical illusion or something that can simply be dismissed.

The meaning of noumenal is derived from the root 'nous', so one meaning of 'noumenal' is 'ideal object'. There's a Platonic echo in that (which I'm not entirely sure Kant was aware of) but in the Platonist tradition (including Aristotelian realism) the forms were grasped by nous in a purely rational manner (as distinct from the material object which was apprehended by the senses). So in some ways our grasp of actual particulars is always deficient in some respects - reflecting the Platonic intuition about the imperfect nature of the sensory domain. I think in effect, the Kantian 'synthesis' of intellectual and sensory elements somewhat resembles hylomorphism (I guess there's a study of that somewhere out there.)

I find in discussions of the idea of 'things in themselves' that many people have a sense that the phrase implies we could 'pull back the curtain' and 'see things as they really are' , or that it implies some 'reality behind the reality' if only we could see it. Whereas it seems to me to indicate something about the inevitable limit of knowledge due to our sensory and intellectual limitations.

But the practical import for all of these discussions is that 'things only ever exist from a perspective'. That is, nothing has real 'self-existence' or exists in its own right. (It's this principle which is also found in Buddhist philosophy). In some ways, the 'atom' fulfilled the role of the ideal or ultimate object, but the upshot of 20th century physics has thrown that into doubt. But we are used to attributing inherent reality to the objective realm without understanding the way in which this based in our own mind. It is part and parcel of post-Enlightenment modernity.