Are noumena part of space and time or not? If not, and they differ from things in themselves, then what are they (is it)? Saying noumena "mark the limit" just isn't clear to me. — Xtrix

Insofar as noumena as quite literally defined by their being non-sensible intuitions, no, they are not subject to the forms of space and time. And if the fact that noumena mark the limit of the sensible is unclear, perhaps your beef is with with Kant:

"The concept of a noumenon is thus a merely limiting concept, the function of which is to curb the pretensions of sensibility; and it is therefore only of negative employment. At the same time it is no arbitrary invention; it is bound up with the limitation of sensibility, though it cannot affirm anything positive beyond the field of sensibility." (B311)

What exactly is "gotten rid of" when the subject goes away? In that case, why not just say the thing in itself goes away too? Who's to say? — Xtrix

The transcendental constitution of reality goes away - at least, in its human form (Kant leaves it an open as to whether there are other forms of (non-human?) intuition: "our kind of intuition does not extend to all things, but only to objects of our senses, that consequently its objective validity is limited, and that a place therefore remains open for some other kind of intuition, and so for things as its objects" (B342)). As for who's to say - Kant's to say:

"Understanding accordingly limits sensibility [via the noumenon - SX], but does not thereby extend its own sphere. In the process of warning the latter that it must not presume to claim applicability to things-in-themselves but only to appearances" (A288, my bolding). There could hardly be a clearer distinction between the remit of noumena and the thing-in-itself than in this passage.

"The concept of a noumenon is thus a merely limiting concept, the function of which is to curb the pretensions of sensibility; and it is therefore only of negative employment. At the same time it is no arbitrary invention; it is bound up with the limitation of sensibility, though it cannot affirm anything positive beyond the field of sensibility." (B311) — StreetlightX

Yes, a limiting concept. Just as the thing in itself is a limiting concept. He's not saying noumena ARE the limit, as you stated, he's saying it's a limiting concept. You could just as easily replace "noumenon" here with "thing-in-itself" and Kant would be make exactly the same point. I still see no grounds for a distinction, or at least the one being made here on this thread.

"Understanding accordingly limits sensibility, but does not thereby extend its own sphere. In the process of warning the latter that it must not presume to claim applicability to things-in-themselves but only to appearances" (A288, my bolding). There could hardly be a clearer distinction between the remit of noumena and the thing-in-itself than in this passage. — StreetlightX

Our understanding limits sensibility, and can claim applicability to appearances only, not to things in themselves. This is what he says. If this is the clearest distinction, then I'm truly unconvinced and don't see how anyone can arrive at the conclusion that noumena are somehow different from things-in-themselves.

If both are not subjected to space and time, then what's the difference? Nothing. In my view these passages cited certainly don't support any such differentiation, and in fact at least one has been cited that clearly states they're the same thing.

I think it's unmotivatable to make this move, and really don't see what it adds, but to each his own.

But Kant does not say that the thing in itself is a limiting concept. Really, find me a passage. You won't be able to. Which follows from that fact that the thing-in-itself, as I keep saying, is not defined by it's relation to the subject, as the noumenon is.

Your argument in general is somewhat odd: it's true that both share a certain 'quality' (that of not being subject to space and time), but this alone cannot say anything as to their idenity. Two apples may be green, but that does not make them the same apple.

So they're both "ideas"? This seems so riddled with confusion I really don't know how to respond. But if it makes sense to you, you're a smarter guy than me. — Xtrix

I probably didn't explain it that simply after all. The way I understand it is that 'noumenon' is an idea of a limit beyond which sensory experience cannot go. A limit is itself an idea or at least a conceptual 'object' so 'noumenon' is in that sense an idea of an idea.

'Thing in itself' is an idea of an actuality which is totally independent of (and not merely a limit to) sensory experience and any and all human knowledge and understanding.

It's a subtle and, on some interpretations, perhaps a barely coherent, distinction, so....

Which follows from that fact that the thing-in-itself, as I keep saying, is not defined by it's relation to the subject, as the noumenon is. — StreetlightX

What is the thing in itself "independent of"? The subject. You said so yourself. Yet it's not defined in relation to the subject?

Your argument in general is somewhat odd: it's true that both share a certain 'quality' (that of not being subject to space and time), but this alone cannot say anything as to their idenity. Two apples may be green, but that does not make them the same apple. — StreetlightX

True, but if both noumenon and thing in itself are beyond space and time (green), what ELSE makes them different? You say the relation to the subject, that noumena is the limit or the mark of the limit. I say both can be applied to things in themselves as well.

If both are unknowable, how can we differentiate? It's like saying there are numberless, timeless, spaceless apples -- but there are two, and they're different somehow, but both are also unknowable. It makes no sense to me. Better to just say that human beings have scope and limits -- a scope bounded by space and time. Beyond this limit (of space and time), whatever there is we can't know -- because what we know is, again, bounded, and thus if we could know something about it it wouldn't be noumenal, it'd be phenomenal. What's the point of saying, "From the subjects point of view, the word for our limit is noumenon, which would disappear if we disappeared -- but from the point of view of nowhere, there's a thing in itself which lives on regardless"?

It frustrating to me. If there's something I'm truly missing, I want to know. Obviously it's convincing to a lot of people here -- more than I realized -- so I don't disparage it, but I still think my reading is more accurate.

Things we think aren't phenomena? "God" and "soul" and the "Universe" are not phenomena or knowledge? Than how can you speak about them at all? — Xtrix

Similarly we talk about rivers of honey or flying horses. Mixing concepts or using meaningful words in wrong contexts where they mean nothing.

I probably didn't explain it that simply after all. The way I understand it is that 'noumenon' is an idea of a limit beyond which sensory experience cannot go. A limit is itself an idea or at least a conceptual 'object' so 'noumenon' is in that sense an idea of an idea. — Janus

'Thing in itself' is an idea of an actuality which is totally independent of (and not merely a limit to) sensory experience and any and all human knowledge and understanding. — Janus

Ok, I follow you here a little more. If noumenon is a word for (or idea of) the limit of our understanding, fine. That's, I believe, what Streetlight and Mmw are saying as well. But I don't see any need for it. Why not just say "the limit of our understanding"? Why the idea of an idea, to use your phrase? It sounds to me like "noumenon" now becomes a word for "boundary," like being on the fence -- not a thing in itself, but not appearance/representation ("phenomenal"). I suppose you could read some passages this way (and only some), but I don't really see what it adds or why it's important.

Similarly we talk about rivers of honey or flying horses. Mixing concepts or using meaningful words in wrong contexts where they mean nothing. — David Mo

OK, but that's all phenomena as well, in my view. It's all experience -- the experience of imagination, of creative use of words, metaphor, etc. Again, thinking is an activity and thus phenomenal.

though we cannot know these objects as things in themselves, we must yet be in a position at least to think them as things in themselves; — Xtrix

Kant distinguishes between knowing and thinking. We can think about infinity, but not know it. Knowing implies defining and grasping its existence.

Kant distinguishes between knowing and thinking. We can think about infinity, but not know it. Knowing implies defining and grasping its existence. — David Mo

And both are phenomena.

Representations of our sensibility is an affect on our senses. An affect on our senses is a perception. A perception requires what we call an outward object. Outward objects are outward things. Outward objects in themselves are things-in-themselves. Outward objects in themselves are perceived. things-in-themselves are perceived. That which is merely perceived is unknown to us. Things-in-themselves are unknown to us. — Mww

Your argument is wrong. To think that an undetermined "something" has caused A is not the same as knowing the cause of A. Moreover, Kant says countless times that we cannot perceive things in themselves. This is the main point of CPR.

That's an interesting statement in the context of this thread. The relevant question is whether it points to a subject/object duality or to an underlying symmetry. That is the measurement problem. — Andrew M

I have not understand what symmetry you refer.

Anyway, Bohr, Einstein, Heisenberg et alia thought that quantum mechanics posed a problem of subjectivity to science. Bernard d'Espagnat (https://en.wikipedia.org/wiki/Bernard_d%27Espagnat) devoted an article to the importance of Kant to understand quantum mechanics.

One might say: noumena are things-in-themselves under the aspect of the transcendental subject. However, get rid of the transcendental subject, and one similarly 'gets rid' of noumena - but not things-in-themselves, which are subject-independant. — StreetlightX

It's the same thing even if you call it by different names. "Noumena" is another way of saying "thing in-itself". If the subject disappears, the name disappears, not the named thing.

If both are unknowable, how can we differentiate? — Xtrix

By their respective relation to the subject! I keep repeating this - in fact it was the first thing I said here: noumena are the limit of sensibility. They are only defined in relation to our capacity for knowledge. Things-in-themselves, by contrast, are defined by having no relation to our capacity for knowledge. The difference between not-X and not X.

@fdrake made the same point in a different way: "The noumenon marks the limit of the sensible; the sensibility being a human faculty ... The thing-in-itself is the name for being insofar as it is not conditioned by our faculties; it is that which exceeds the limitations of our faculties."

I've run out of ways of saying the same thing.

OK, but that's all phenomena as well, in my view. It's all experience — Xtrix

This is your way of saying it, not Kant's. Besides, there's a difference between imagination and the world of noumena in Kant. In the imagination, sensitive objects are mixed up in the wrong context. The fantastic entity could be perceived in strange circumstances, outside of normal life. This is not the case with noumena because they are outside of any perceptible circumstance: outside of space and time.

By their respective relation to the subject! I keep repeating this - in fact it was the first thing I said here: noumena are the limit of sensibility. They are only defined in relation to our capacity for knowledge. Things-in-themselves, by contrast, are defined by having no relation to our capacity for knowledge. The difference between not-X and not X. — StreetlightX

And when Kant says that the thing itself cannot be known, does he not put it in relation to our knowledge? To say that it marks the limit of our knowledge is the same as saying that it is outside our knowledge.
It's not true that numena are "only defined" by their relationship to knowledge. Noumenon is defined as "the way we call things in themselves". Two ways of calling the same thing!

It's not true that numena are "only defined" by their relationship to knowledge. — David Mo

Incorrect. Here is Kant: "The concept of a noumenon is thus a merely limiting concept, the function of which is to curb the pretensions of sensibility; and it is therefore only of negative employment. At the same time it is no arbitrary invention; it is bound up with the limitation of sensibility, though it cannot affirm anything positive beyond the field of sensibility." (B311) No sensibility, no noumena. The two are inextricable concepts.

As for the thing-in-itself, it has a relation with our capacity for knowledge, but is not defined by it, unlike the noumenon. I may be a brother to my sister, but my sister is not nothing other than a sibling to me. The noumenon, however, is nothing other than the insensible - non-sensible intuition (intelligible entity). Difference between not-X and not X. Again.

"The concept of a noumenon is thus a merely limiting concept, — StreetlightX

Here you see:

"Now the doctrine of sensibility is at the same time the doctrine of the
noumenon in the negative sense, i.e., of things that the understanding
must think without this relation to our kind of intuition, thus not
merely as appearances but as things in themselves, but about which,
however, it also understands that in this abstraction it cannot consider
making any use of its categories, since they have significance only in re-
lation to the unity of intuitions in space and time, and can even deter-
mine this unity a priori." (CP308) [Emphasis mine]

If the sensitivity disappears, the concept of the thing itself also disappears, because it is defined in contrast to the phenomena, which Kant also calls appearances. You see that in this text Kant opposes the thing itself to the phenomenon (appearances). That is, the thing itself is the same as the noumenon: that which is opposed to the phenomenon.

I think you are confusing Kant's words: He says that noumenon in the negative sense is nothing more than the concept that specifies the limits of knowledge, as opposed to noúmeno in the positive sense, which seeks to go beyond them (classical metaphysics). It does not say that the only being of the noumenon is in the understanding.

He says that the concept of noumenon "only" is limiting. Not that noumenon is just a concept.

If the sensitivity disappears, the concept of the thing itself also disappears — David Mo

This makes of Kant an idealist in the Berkeleyian sense, which he militates against throughout the CoPR. As I said, noumena are indeed things-in-themselves, but the converse does not hold.

Either way you need to make up your mind: either the noumena are defined only in relation to the understanding, or they are not. You can't have it both ways.

This makes of Kant an idealist in the Berkeleyian sense, — StreetlightX

If the concept of imbecility disappeared, imbeciles wouldn't disappear. Unfortunately. You keep confusing the concept of noumenon or thing in itself with the existence of things.

You keep confusing the concept of noumenon or thing in itself with the existence of things. — David Mo

You keep stringing the two together without argument.

You keep stringing the two together without argument. — StreetlightX

Does this one work?

"The concept of a noumenon, (...) as a thing in itself" (B310)

Not only I, but other participants in the forum have already given you several texts in which Kant identifies noumenon and thing in itself in the same way: what falls outside the conditions of understanding, but you ignore them.

but you ignore them. — David Mo

Not at all. I've repeatedly acknowledged that noumena can be understood as things-in-themselves. Only that the converse does not hold in all cases. There is an asymmetry.

Not at all. I've repeatedly acknowledged that noumena can be understood as things-in-themselves. Only that the converse does not hold in all cases. — StreetlightX

Can you quote Kant to demonstrate that distinction?

Well, I'll say goodbye with a quote in which Kant identifies noumenon and thing itself directly:

"...a way in which the object exists in itself (noumenon), without regard to the intuition to which our sensibility is limited". (B346)

Can you quote Kant to demonstrate that distinction? — David Mo

I already did!: "Understanding accordingly limits sensibility, but does not thereby extend its own sphere. In the process of warning the latter that it must not presume to claim applicability to things-in-themselves but only to appearances". (A288)

That is: the limitation set by the understanding on sensibility does not apply to things-in-themselves. Noumena are 'appearence-relative', and only appearence-relative. Things-in-themselves are not.

Further down: "If we want to call this object a noumenon because the representation of it is nothing sensible, we are free to do so. But since we cannot apply any of our concepts of the understanding to it, this representation still remains empty for us, and serves for nothing but to designate the boundaries of our sensible cognition" (B346, my emphasis)

It should be noted to that your partial quote (B346), in context, comes at the end of a discussion in which the idea that limitations of understanding extends beyond sensibility, is a mistake. So the start of Kant's sentence, which you conveniently cut off, reads:

"We therefore think something in general, and on the one side determine it sensibly, only we also distinguish the object represented in general and in abstracto from this way of intuiting it; thus there remains to us a way of determining it merely through thinking that is, to be sure, a merely logical form without content, but that nevertheless seems to us to be a way in which the object exists in itself (noumenon), without regard to the intuition to which our sensibility is limited".

But this 'seems' is precisely, a mistake. To regard the noumenon as that 'without regard to which the intuition to which our sensibility is limited' is an error: the whole section is a 'critique of pure understanding': a critique which posits that to think noumena as abstracted from sensibility is a total mistake. What you quote in defence of your position is for Kant paradigmatic of a transcendental exercise of the understanding which must be avoided at all costs!

I don't know why this thread has been hijacked by people talking about Kant, it must be a kind of Twister played by philosophers.

It's really very simple as Wayfarer pointed out in the first reply. The distinction between subject and object is a function of the mind body duality of humans.

So subject is that perceived, understood, inferred and discussed by the mind.

The object is what is sensed, or encountered by the body.

Simples.

The second they (stimuli) hit the sense organs, they become representations to us, unless you argue that what effects us from "outside" corresponds exactly to what we sense, perceive, etc. That's fine, but it's not Kant. — Xtrix

Yes, what effects us from outside corresponds exactly to what we sense. That which effects our eyes exactly corresponds to what we see; that which effects our ears corresponds exactly to what we hear, etc. We have to have consistency between incoming data and what the cognitive system works with.

The stimuli become sensation (rods and cones, eardrum, pressure...), that which becomes an appearance (optic nerve, those little tiny bones....I forget the name, skin), from a sensation is a representation of it.
——————

So how are representations created? By the brain and nervous system on the "occasion of sense," through our cognitive faculty. — Xtrix

The brain and nervous system have nothing to do with a speculative epistemological system. Just as intuition, conceptions and representations have nothing to do with cognitive neuroscience. Two different domains of investigation. When it comes right down to life and living, all our mental mechanics are done by the brain, but that is soooooo boring for the philosopher.

As to how representations are created: “....we have not here anything to do....”. We don’t know., and it really doesn’t matter, in a purely speculative epistemological theory.
——————

Saying we can't create representations "outside of us" is not true -- there's all kinds of things outside me: trees, books, rivers, anything at all. — Xtrix

All kinds of things are outside us, but they are not representations, they are real, physical objects of experience, because they have particular names in accordance with the conceptions understood as belonging to them, thus cognized as a certain thing.
——————

Yes, we perceive objects. We don't perceive objects in themselves. — Xtrix

I just quoted Kant as saying that’s exactly what we do.
“...objects are quite unknown to us in themselves, and what we call outward objects, are nothing else but mere representations of our sensibility...”
Object are quite unknown to us in themselves says exactly the same as objects in themselves are quite unknown to us.
——————-

I think this stems from the above and not using sensation and perception in the same way I am. Again, I consider them phenomena, and by phenomena I mean literally anything experienceable. — Xtrix

Fine. Go right ahead. That’s the easy way out of digging the subtleties from the theory. Literally anything experienceable is a possible experience. No merely possible experience can be a phenomenon. A merely possible experience will have a merely possible phenomenon as it condition. I can think swimming the English Channel, and it is experienceable, but the perception, the sensation and indeed the very phenomenon, are entirely absent.
——————-

I don't see how "things" and "representations" are different. — Xtrix

“....The capacity for receiving representations (receptivity) through the mode in which we are affected by objects, is called sensibility....”

This tells you representations are a consequence of objects, or, of things, and if they are a consequence, they cannot be antecedent to or simultaneous with, that which is their cause. And don’t be confused by “receiving representations” such that they appear with the object. When conditioned by “the mode in which we are affected” makes clear all representations are generated after they are perceived.
——————

So whatever affects us certainly isn't empty to us -- it's any object at all, and not just trees and books but feelings, emotions, pains, thoughts, etc. — Xtrix

Again, a common misunderstanding. Books, trees, yes. Feelings, emotions, pain, thought.....no. None of those are given representations by sensibility, even if the object which causes them, may be, thus can never be empirical cognitions. Feelings are relative subjective conditions alone, and have no object of their own. You cannot draw a feeling on a piece of paper as you can draw a tree; you can only draw that which you think is responsible for that feeling.
—————-

Imagining a pink unicorn is still an idea, yes? Imagination is an experience as well, bounded by our human limits. That's still part of phenomenology. — Xtrix

We don't care about the phenomenology. Just because Kant gave a very specific task to a relatively small part of his system doesn’t make him one. Besides, phenomena are not even used in pure reason, in which the faculty of sensibility is not in play.

Imagination is not an experience. Empirical cognition is. Imagination is at the beginning of the thought process and is below our attention, while experience is the culmination of the thought process and is quite apparent to us. While we certainly think the object of imagination, in this case the pink unicorn, such is not an experience, because it is not an empirical cognition given from an object of sense.

A pink unicorn is an idea, yes, Imagining a pink unicorn is not an idea, it is a rational activity of the thinking subject. So called because imagination is supposed to synthesize appearance with intuition, but with e.g., pink unicorns, nothing appears, which means imagination is creating a phenomenon from intuition alone without synthesizing anything, but rather, is merely combining like content. This is why we can imagine weird stuff, because understanding can find no contradictions in an object comprised of just one kind of content.

And the band played on.........

By their respective relation to the subject! — StreetlightX

And as I said before, they're both related to the subject. If you argue the thing in itself somehow sticks around with no subject, yet the noumenon disappears with the subject gone, then the noumenon is either subject-dependent and thus phenomenal, or there's no difference between it and the thing in itself, which (at least as a concept) disappears with no subject as well. I see no difference, and the point was to differentiate the two.

I've run out of ways of saying the same thing. — StreetlightX

Fair enough. And I've heard you, but still think it's a mistake.

I have not understand what symmetry you refer. — David Mo

Per symmetry, a measurement is simply an interaction between two quantum systems (with no implication of consciousness or subjectivity in either system).

Anyway, Bohr, Einstein, Heisenberg et alia thought that quantum mechanics posed a problem of subjectivity to science. — David Mo

They didn't. Heisenberg, for example, said:

Of course the introduction of the observer must not be misunderstood to imply that some kind of subjective features are to be brought into the description of nature. The observer has, rather, only the function of registering decisions, i.e., processes in space and time, and it does not matter whether the observer is an apparatus or a human being; but the registration, i.e., the transition from the "possible" to the "actual," is absolutely necessary here and cannot be omitted from the interpretation of quantum theory. — Werner Heisenberg - Physics and Philosophy

--

Bernard d'Espagnat (https://en.wikipedia.org/wiki/Bernard_d%27Espagnat) devoted an article to the importance of Kant to understand quantum mechanics. — David Mo

I'm not familiar with his writings. Can you, or anyone else, explain why Kant should be considered important for understanding QM or science generally?