1. There is experience, therefore something exists.
2. That something, or a part of it, must be producing experience.
3. The unified parts of that something which are producing it is the ‘I’.
4. The ‘I’ can only produce experience through (data) input (i.e., sensibility).
5. The production of experience via sensibility (and whatever may afterwards interpret such sensibility) entails that one’s experience is a representation.

I see...so would 'immanent' be simply possible [human] knowledge of things?

Hello Mww,

It is the function of understanding/judgement, to as closely mirror the thing as it is in itself with the thing as it is represented in us. So….not by happenstance, but by logic, Nature herself being the arbiter.

I am hesitant to agree here: wouldn’t it be more that the understanding/judgment facutly(ies) are preconditioned to try to represent things according to principles, conceptions, and judgments? I don’t see how that would entail a close mirroring of the things-in-themselves.

I rather position transcendent in opposition to immanent rather than transcendental, that’s all.

What do you mean by "immanent", and how it is contrasted to "transcendental"?

Hello Mww,

While this is in accord with Kantian T.I., there is nothing implied therein having to do with negative knowledge. “Impossible to know”, or, knowledge not possible to obtain, with respect to thing-in-themselves, merely highlights human sensory limitation and says nothing whatsoever about the cognitive aspect of the overall human intellectual system. It is absurd to expect a system to make a determination on something that was never given to it.
…
So…..upon sufficient reflection, you might find that rather than having negative knowledge of X, there is only positive knowledge of yourself, re: you know there is something you cannot know, from which follows, that forcing the former at the expense of the latter is what the A/B quote is meant to indicate.

This is a really good point I, admittedly, missed. @Corvus I change my mind: I don’t have negative knowledge of the things-in-themselves because it could be the case that what I negate of is false (since I know nothing about it). Instead, I know that what I am given is not a thing-in-itself, but the thing-in-itself could turn out to be a mirror (by happenstance) of what I am given (and I would never know it). Thusly, I cannot say "this X is not Y" but rather "I only have knowledge of Y, which is not X".

Yes, but not for scientific reasons.

Hello Corvus,

For you to arrive at the conclusion that you don't know anything about X, you should have known,...You know a lot about X, when you don't know anything about X. Consequently the conclusion you don't know anything about X is false….And negative knowledge is also knowledge, no?

That’s fine by me. I just don’t think the colloquial expression “I know nothing of X” is contradicted here, since it precludes negative knowledge. But I do not have a problem admitting that I have negative knowledge of X when I “know nothing about it”.

Hello 180 proof,

Again: philosophical statements.

For me, since I am not grasping exactly what the terms you are using are denoting, this just becomes a circular loop: conceptual supposition ↔ philosophical statement. What do either of these mean in your view? Can you be more specific please?

Hello Pantagruel,

If the sensations are fabricated then are you implying that your intuitions of objectivity are unreliable? As long as you are not effacing the link with objectivity that the intuition effects.

If the sensations are fabricated, then I would never know it; but, yes, they would be unreliable with relation to whatever actual exists in the world-in-itself. It wouldn’t change much about practical life though, because, either way, I a condemned to compare experiences and navigate my life with them. So if I were, for example, in a matrix, then it really would not impact my practical life at all. I still have to do what I have to do.

Hello Tom Storm,

How much Kant have you read? Have you moved away from Kastrup? I think many people with an interest in philosophy end up here abouts at some point. I held a similar view (mainly through secondary sources) in the 1980’s.

I have read critique of pure reason, prolegomena, and the groundwork for the metaphysics of morals. I working on reading his critique of practical reason and judgment books.

In terms of Kastrup, yes I am moving away from that view.

Moreover, you alluded that you used to have a similar view, but have moved past it: could you please elaborate on what convinced you against the view?

I guess I also find myself wondering, if accurate. so what? Does it make any difference to how one lives? How is this way of thinking of use?

The implications is that we cannot do proper ontology but rather create paradigms of possible human experience.

Any book suggestions? Or counter arguments to transcendental idealism that you find hold weight?

What do you mean by a conceptual supposition or interpretation? Facts can make a concept true or not true--e.g., the concept of a cat.

Your summary of Transcendental Idealism reminded me of a Quantum pioneer's response to the question whether queer quantum science revealed anything about the Real world. It also sounds like something a modern Buddha might say. Or like the spoon-bending-boy to Neo

Yeah I could see why, since we share a bit of scientific anti-realism (at least metaphysically).

In which case, they should be of no concern to us. Not exactly a contention, I know, but an entirely reasonable judgment.

:up:

Not exactly entirely? For one thing, we know that they are impossible to know, so we know something about them partially, but not entirely.

Not knowing anything about X does not entail knowledge of anything about X.

Another way to put it, is that I have only negative knowledge of X by negation and never positive knowledge.

I think this contradicts an essential characteristic of transcendental intuition, which is that effect a synthesis of the subjective and the objective. Hence its transcendental character.

I am not following: could you please elaborate? I don't see any proof offered by Kant that actually proves (transcendentally) that my intuitions are not fabricated but, rather, just that they must have intuited objects outside of me in space in order to determine myself within the representations.

Hello Manuel,

Sorry Bob, I missed this somehow.

Absolutely no worries!

No. This case, and other cases of manifest reality are mind dependent. Being able to sit on is a mental construction as are the things we designate as "sittable".

Interesting. To me, either I can sit on something, in the strict sense of being actually capable (and not whether I would prefer to call it ‘sittable’ or not), or I cannot; and, thusly, it is outside of my control, strictly speaking, whether something has the property of ‘being sittable’. I agree, though, that we could restrict that property to be loaded with sociological and psychological limitations, but that would exclude or overinclude things which shouldn’t have been.

Hello Mww,

Even if I grant all three points are assumed as true, what makes them transcendent claims?

One cannot transcendentally nor empirically prove that there are real (in the sense of non-fabricated) objects which excite their senses or sensations which are “fed” to their faculty of judgment and understanding. It is entirely possible that one is fabricating all the intuitions they have or their senses are picking up fabricated information from an external source (but, in the case of the latter, one would know there is an transcendent world, it just wouldn’t be comprised of real objects).

In the case of proving that the ‘I’ exists, it may be possible to transcendentally prove it if it is required in order to experience in the first place; but I am hesitant whether that is truly possible or not. I could say that there must be something producing the experience which I have, for otherwise it would be nothing “underneath” experience and that is impossible, and that something must be unified; and that unified thing is the ‘I’. So perhaps this one isn’t a transcendent claim afterall.

In the case of there being a distinction between my experience and the world itself, this may also, upon further thought, be proven (potentially) transcendentally. As I could say that if there must be something producing experience and it is the ‘I’, then it must be experiencing by input of raw data (i.e., senses); and thusly there is a distinction between the sensations and the things-in-themselves.

So maybe only the first is transcendent?

Hello Janus,

How can metaphysical statements or standpoints be truth-apt if their truth is undecidable? The only way I could parse that would be to say that they might be true even though we have no imaginable way of determining their truth.

They are not actually undecidable just because no person is currently capable of deciding it. For example, imagine we are incapable of reaching a certain part of space (right now) and someone says there is a teapot there, just floating around. Is that statement non-cognitive simply because we can’t evalutate it right now as either true or false? Of course not! It is truth-apt because it has the capacity to be either true or false, irregardless of whether we can evaluate it right now or not.

I guess I am just not following why one would believe that truth-aptness is tied to suggestive evidence from reality as opposed to be merely, in principle, true or false. It seems odd to me. For example, imagine that I have never experienced a TV before, now imagine somehow explained, in principle, how a TV works and made the statement "a TV is in the other room". Even though I haven't experienced a TV and I don't actually know if it is possible for the, in principle, blueprint to work, I nevertheless say that statement is truth-apt simply because it could be evaluated as true or false.

Hello baker,

If there is such a thing as a "moral fact", then it must exist somehow independently of persons.
How can people learn what the moral facts are?
How can people know that they have the correct knowledge of moral facts?
On the grounds of what should one person trust another to tell her what moral facts are?

Ultimately, the same way, I suppose, that we derive that there is something at all which exists independently of persons: intuitions and evidence.

And with this view, how do you account for persons?

In what relation are persons to right and wrong?

Morality, as a definition, should include our metaethical commitments: so I say it is the study of what is right or wrong, period. However, I think that morality is an inevitable mixture of facts and non-facts (i.e., facts and tastes). The individual plays a part in it.

Also, if I remember correctly, the person that I responded to with that quote was asking about “personal morality”, which I do not make such a distinction at all (even in the case that some [or even all] moral statements are contingent on subjects) because it draws an invalid line between what one thinks is right or wrong for themselves vs. universally: all moral statements should contain the element of obligation. I cannot say “stealing is always wrong” but caveat it with “personally”: either it is always wrong to steal, or it isn’t.

"In principle" there is not any fact of the matter that can make the statement true. At most, it's a supposition expressed (confusedly) in a declarative, or categorical, form (as philosophers are wont to do).

I think the difference between our views on truthmakers is that I seem to think that what qualifies a statement as truth-apt (truth-bearing) is that it is not expressing something which is metaphysically, actually, nor logically impossible; whereas, for you, it seems like the qualification is that some fact about reality suggests, to some degree, that it is true. Is that correct?

Philosophical statements are propositional, because they are truth-apt. Let's take one of your previous examples (of a philosophical statement that you say is non-propositional): "Consciousness is fundamental to reality". Are you saying that, in principle, that statement is not truth-apt? Are you, likewise, saying it is a non-cognitive statement?

Yes, by all means. I will read your counter-argument, and get back to you. My response will also be not too quick due to other things I have to do in my daily life. Please bear with us. :) Thank you.

Absolutely no worries, my friend! I look forward to you response!

A truth-maker is a referent to which a truth-claim (i.e. truth-bearer) statement refers that makes the statement true; it's not the "agent" asserting or "making" the statement.

I read the article you mentioned, and I don't see how it helps your case (but perhaps I am misunderstanding). I am not talking about truth-bearing statements but, rather, truth-apt statements, which appear to be different: the former is a proposition which is true, which clearly indicates the need of a truth-maker, and the latter is merely the capacity to be true or false. Hence, even at the very beginning of your article (that you linked), it said:

“x makes it true that p” is a construction that signifies, if it signifies anything at all, a relation borne to a truth-bearer by something else, a truth-maker

If a 'p' is false, then there is absolutely no truth-maker for p; but p is truth-apt. A non-truth-apt proposition is one that cannot be, even in principle, evaluated to true or false (such as desires in emotivism): they are non-cognitive.

Hello Manuel,

That it is a-priori is not in doubt. Nevertheless, it is intelligible for me to suppose that there is a reason (which we may not know, nor ever know) for why the universe acts in one way rather than another, than for no reason at all, meaning, that in a few seconds, we'd begin to see apples going back up to the trees and so forth.

That is fair and I agree now. I think we must be able to get at some transcendent truths to get the whole transcendental philosophy afoot. If we know that we sense ‘objects’ (whatever they may be), then the strict regularity of our experience must indicate that the sensations of the objects is regular (transcendentally) and that suggests the objects themselves are regular (be them whatever they may actually be). This could potentially work as an argument for causality beyond our a priori ability to represent objects. Then, again, it could be that some of reality is causally linked, and some of it isn’t; and we only have access to those that are.

It's a bit stronger. I believe an atom has mind-independent properties, a chair does not. But we do not know if an atom reaches the in itself or no.

So, you don’t think the property of ‘being able to sit on it’ is mind-independent?

Hello L’Elephant,

I apologize for the late response!

So, you don't include your own personal choice, no matter what your society's rules are? I mean, your own personhood -- the internal dialogue that goes on inside your feelings and mind about justice and compassion and fairness?

I don’t define morality with a split between society and self: I define it as simply what is right or wrong, period. I am not saying that whatever society says is the standard, nor the individual but, rather, that morality is the study of what is right or wrong (period).

Hello Baker,

I apologize for the belated response!

If moral facts are something that some people still need to discover and some already know them, then on the grounds of what should the thusly ignorant trust those who propose to have said knowledge?

I am not following the relevance of this (to our original conversation): could you please elaborate? The current state of knowledge of moral facts doesn’t negate the possibility of their existence; and I would suppose that if a person doesn’t buy the arguments for moral facticity that another person is providing, then they shouldn’t trust them.

Secondly, how do you explain that people disagree on what the moral facts are?

People disagree all the time. Why would that negate the possibility or existence of moral facts?

And what should they do when they disagreee about them? And especially, when such disagreement is between people where one person has more socio-economic power than the other person?

Again, to me, this just seems irrelevant to whether moral realism is true. There could be moral facts, confusion between societies about what they are, and disagreement between people about moral facts at the same time.

Hello 180 Proof,

I am sorry for the later response! I got rather busy, but I did not forget about your response.

What makes a statement "truth-apt" that does not refer, even if only in principle, to at least one truth-maker?

The same way that a moral law can exist without a moral law maker: the statement just needs to, in principle, be able to be evaluated as true or false (as being in a state of one or the other). Why would something be truth-apt require an agent to create it?

Hello Manuel,

I am sorry for the late response, my friend! I have not forgotten your response, but haven’t had the time to respond.

Firstly, after digesting my OP more, I think my original argument is flawed (and will be posting an amendment to the OP to address that, which I would really appreciate it if you read it and shared your thoughts thereon).

However, with that being said, I am going to respond to your response in light my shifted thinking (that way we don’t waste time arguing about things we may agree with each other on now).

But this sounds as if experience is experience of something that is only a representation and nothing else in any case. I don't think that follows, are natural numbers a representation or are they real constituents of reality?

Of course, our experience of something is a mixture of a priori and empirical datum, so some of our content of our representations are really a reflection of non-representations (such as math): so I can get on board here (with you). However, I must confess ignorance on whether the things-in-themselves adhere to mathematical principles; but I can say that our representations (of them) do (as a priori means by which we represent them in space and time).

That 2+2=4, regardless of how you write the numbers, will be a fact, regardless of people being around or not, it's a fact - it's true regardless of belief or consciousness.

True, but it doesn’t follow (from that) that math pertains to the objects-in-themselves nor the representations of them. For a full-blown mathematical anti-realist, I would imagine they would say that 2+2=4 is a mathematical proposition which is true irregardless of how we feel or what we experience; but that it is only a reflection of our self-reflective cognition (i.e., reason) as the means by which we think about our representations.

As for causality, again, yes, we discover it through experience. But we have to options: either things "just happen", that is, there is no reason why light can't escape a black hole, which suggests that there is no reason why light could escape a black hole, or why a photon couldn't turn in to an electron.

So, I am starting to embrace Kantianism a bit more: I find it quite plausible that causality is the necessary inference we make of (intuited) sensations and thusly is it a priori certain—albeit not necessarily pertaining to the objects-in-themselves.

However, yes, one could just argued inductively for causality; but then it doesn’t carry the necessity that the term used to mean.

I don't agree. It's not a semantic issue, but a conceptual one. We don't sit on what we interpret as "spikes", but we could sit on many things - that depends on what we take to fit under the conception of chair.

An atom is not like this, I cannot, with significant flexibility, decide that an atom is a proton or that energy is made of particles. That doesn't happen with chairs or tables or keys, etc.

I understand what you are saying; but let me be more specific to clarify. Let’s say a ‘chair’ is a 4-legged object with a flat surface (on top) to sit on. Now, in the same manner that I can point to something and claim it is an ‘atom’ or it isn’t, I can do so with a ‘chair’. I think, and correct me if I am wrong, you are just noting that the concept of a chair is looser than the concept of an atom, which I agree with.

We can't have a form of experience without something providing that form which is not experience. Otherwise, I could, by mere thinking change a notebook to a puddle of water. But I can't. Something prevents me, which is not my imagination, but a fact about something existing.

I don’t agree with my original argument (and I will note it in the OP why), but I don’t think that it necessarily follows that the form of experience is provided by something transcendentally beyond it: I think that is borrowed from experience itself.

Also, just because you can think you way into changing what you experience, does not mean that you know anything about what is beyond it. I think there is another way, I would say, to infer that my argument is flawed (which I will put in the OP).

Hello Corvus,

I apologize for the belated response. I was very busy the past week (or so), but I can assure you that your response was not forgotten.

As I have said already, my definition is various. But I usually go by metaphysics is philosophy itself.
…

All my previous posts in this thread have been pointing out on this issue. But your replies seemed not relevant to my points.

Ok, so, after thoroughly digesting my own OP for the past week or so, I think I understand more what you are getting at; and I am going to provide a counter-argument to my OP as an amending thereof. Please, if you are still interested in this discussion board, read it and let me know what you think.

For the purposes of this discussion, what is your definition of morality?

In its most broad sense, the study of that which is right and wrong (viz., what is permissible, omissable, obligatory, and impermissible).

Hello Corvus,

The OP's definition of metaphysics is too restrictive, so it seems the discussions will end up nowhere, even after months of circling around the points.

Then, what is your definition? I don’t remember you ever giving one (although I may just be misremembering).

Also the OP conclusion that metaphysics is an illegitimate source of knowledge seems inconsistent with the content of the arguments in the OP's replies. The content of the OP's post is filled with both metaphysical and pseudo metaphysical concepts and comments, which are self contradictory and inconsistent.

Could you please give me an example (so that we can go over it)?

Hello Manuel,

Because our experiments show us that the data we are receiving reacts from something that is not merely mental - in other words, there is retrodiction that fits in to events we can now see and evaluate. Which is why I believe that when are mental faculties happen to coincide with aspects of the external world, we have a science.

How do you know this? Those experiments are just experiences more precisely and rationally carried out (than every-day-to-day ones). Thusly, it cannot be said that we receive anything if we take away the forms of our experience, since there isn’t even justification for there being causality.

Chairs are folk-psychological concepts, heck, you if you put a trashcan upside down, you can call it and use it as a chair

But this is just a semantic issue. I am talking about the thing which we normally call a ‘chair’, which is not a trashcan flipped upside down. My point was that the thing we point out as a chair is just as real as what we point out as an atom.

A chair does not remain in the world, something very much like a photon will remain.

This doesn’t make sense to me, since you argued this on the basis of semantics. The word ‘chair’ will certainly cease to exist, but not the thing we referred to as the chair.

Here I disagree completely, things in themselves must be the ground stuff of reality. Adding another layer does fall prey to infinite regress. Which is why I think in these domains we stick to negative claims about what they cannot be.

But they can’t be said to ground reality sans the model, which is where Kant goes wrong, since we cannot grant that anything we experience exists beyond it. Takeaway the forms of one’s experience, and nothing we experienced remains.

Because atoms and planets behave as if we were not watching them

Exactly, and this why we behave as though they do exist beyond our experience of them. My own identity as an existent person that is experiencing the planet is equally conditioned by my forms of experience, and are not valid beyond them.

But who studies metaphysics as that which is beyond all possible experience? Not Descartes, not Locke nor much that come to mind prior to Kant.

How did they define metaphysics?

Where we disagree then, is that I think epistemic structural realism is correct, science really does describe the structural components of the world, as they are mind-independently (not beyond all possible experience), but you go beyond and say, science describes our experience of the world, not aspects independent of us, so I think that's the main issue.

I would say they study things independent of us: but the very concept of “independence of oneself” is conditioned by those forms of experience, and are not valid beyond that.

On the other hand, would you not agree that it gives us knowledge of what it is possible to imagine as well as what it is not possible to imagine?

Sure, I can get on board with that. But it doesn't give us knowledge of reality (other than knowledge of human conceivability).

Hello 180 Proof,

And the truth-makers for these statements are?

Why is this relevant? Can a statement not be truth-apt without having a truth-maker?

Without any mind to construct the proposition, the proposition itself still expresses, if constructed, a truth-apt claim.

e.g. An assembled pile of logs, Bob, is not equivalent to a painting of "a log cabin".

To determine “what things are” is semantically equivalent to deducing concepts and interpretations of “what things are”. They are the same painting of the log cabin, expresses verbally differently.

Those modifiers ain't working ...

I don’t know what you are referring to: could you please elaborate?

Metaphysics is the study of what it rationally makes sense to say about the most general prerequisites and implications of counterintuitive physics

Something making rational sense about the prerequisites of physics entails it is a claim pertaining to something which is beyond experience but necessary to explain that experience.

Hello Joshs,

I think phenomenologists would agree that our ability to represent or model is not primary. They would say instead that there is no experience of any kind that is not conditioned by prior experience, which anticipatively projects forward into and shapes what we actually experience

Oh, I see. What about initial experience then? Or were you conveying a priori knowledge as opposed to “prior experience”?

This mutual dependence between subjective projection and objective appearance is most fundamentally what the world actually is, and we can never get beyond or beneath this intertwined structure of experience to get to an independently objective world or an inner subjective realm.

This sounds an awful lot like Kantianism.

Hello 180 Proof,

Really? How about ...

We must be using the term ‘proposition’ toto genere differently. By it, I mean a grammatical statement that expresses something that is truth-apt.

How is the claim, for example, “all truths are relative” not a grammatical statement that is truth-apt? Or “Consciousness is fundamental to reality”, or “mathematical structures are real”, … ?

Metaphysics is the attempt at determining ‘what things are’. No?
No. It's more like an "attempt at" deducing concepts and interpretions of "what things are".

That’s the same thing. To determine something is to derive concepts and interpretations of something. How is that different?

My point is that it is a study that thinks it can get at what reality actually is, and what things in that reality are. If not, then it is really just the study of determining models of what we experience, which is fine….

Hello Joshs,

Kant’s metaphysics grounds the condition of possibility of experience in something prior to experience. This turns the subjective categories into in-themselves objects, transcendent to the experience they condition.

Correct. He derives transcendental truths. But the problem (I have with him) is that he derives them with the presumption that things still have a causal relationship to us, while also denying that they necessarily have a causal relationship. He takes our direct experience as justification that we represent, and then uses that to annihilate any knowledge that we actually represent anything.

Your recommendation to start out from pure experience runs the risk of substituting for Kant’s idealist metaphysics an empiricist metaphysics in which we assume the objects of pure experience can be made to appear to us disconnected from the presuppositions and expectations we bring to our apprehension of them.

Sort of (I guess). I would say that my view is more a pragmatism, which is definitely more empiricist than Kant, such that we can only produce models for experience and never say that we have any definitive a priori knowledge nor that there are objects impacting our sensibility that, in turn, produce representations. Instead, a priori knowledge is a part of the model wherein we represent things to ourselves. Within my model, I have no problem saying we represent things, and that we do not directly apprehend them.

Phenomenologists like Merleau-Ponty, who advocated a return to the things themselves, argues that the pure experience of things always comes already conditioned by prior experience. Things appear out of a background interpretive field.

Of course. We experience things with preconstructed abilities to represent; but this isn’t where knowledge starts: that’s a model we came up with to predict our experience. It could be that we don’t represent anything at all, nor do ‘we’ exist in the world as it actual is.

Hello Manuel,

If you have science in mind, then I do think you have a model of reality, as close as we can get to it. Sure, it is the human conception, there being no other we can access, unless we do so indirectly. It seems we disagree on what science describes.

How do you know how accurate the knowledge humans can gain through the prism of their experience to reality? Why can’t reality be, for example, actually acausal, irrational, etc.?

By definition, there is not chair absent us, a planet or an atom is a different thing, something we postulate which belongs in the external world.

My point was that the chair does exist, if it there right now, independently of your observation of it; but that this is just a model of experience, and that is not to say that reality has chairs, atoms, nor planets like we perceive them.

I would say that the ‘world in-itself’ as whatever is strictly beyond our experience is the ‘absolute’ and the ‘world in-itself’ within the model that we represent the world is one which would have to have certain properties (presupposed by the model itself)(such as causality, they “impact” us in some way, etc.). — Bob Ross

I don't follow your argument here.

I think the single biggest problem for Kant is that he starts out with a model and not pure experience. We should always start epistemically with pure experience. We do not know immediately that our conscious experience is a representation, once we do take up that model then Kant’s arguments come into play.

For Kant, the phenomena vs. in-itself is a distinction founded within the paradigm (the model) that represent the world (thusly there’s a representation and whatever is actually there that was represented). But this knowledge, this model, is also only valid, under my view, for possible experience; since a close examination of the forms of one’s experience determines that all evidence of us representing the world is conditioned by them.

So, the phenomena vs. in-itself is an incomplete: the absolute is whatever exists beyond our possible forms of experience, and the in-themselves and phenomena are within the possibility of our experience.

Then this is quite different from the title of the OP, because you say you have in mind metaphysics in the sense of beyond all possible experience

The study of things-in-themselves is not solely (necessarily) metaphysics (in the sense of the study of that which is beyond the possibility of experience). There could be something else posited that isn’t a thing-in-itself.

I would add then, that physics in this sense, is metaphysics, because it postulates things that, though discovered through experience, do not depend on experience for existence.

But the knowledge of them is dependent on our experience, and so we can only say that we should expect them to behave within experience as if they persisted beyond our experience in a similar manner within a noumenal space and time—knowing full well we know nothing about what is actually happening in the world in-itself.

I think I follow, but there is more evidence to consider than what reaches consciousness. What reaches experience is but a small portion of everything there is. We don't experience photons - in the sense in which we are aware of them working in us - nor do we experience electrons or plenty of hues in the electromagnetic spectrum and so on.

This is all fine and good within our model of experience, which includes considering things which exist that we cannot directly perceive, of which we perceive (indirect) evidence of their existence.

The issue I have is that, given the title of the OP, you are saying or insinuating that metaphysics is an illegitimate source of knowledge, I disagree with that, because I think it covers much more than whatever is "beyond all possible experience."

But my OP is using the definition of metaphysics which is the study of that which is beyond all possible experience, so within that terminology I am saying it is an illegitimate source of knowledge (which you seem to agree with, but disagree with the semantics).