From what I understand noumena is the external reality, "the real of the "real." We can never have knowledge of noumena. You are right, we have no use to us other than it is the external reality upon which our reality is based. — Arthur Rupel
Sorry, Arthur, but this understanding is self-contradictory. If noumena were the external reality then it would be of use to us necessarily. Noumena are
not that which our reality is based, that being the thing-in-itself, which is the real empirical object that affects our sensibility. This understanding highlights a common misinterpretation, in as much as because no knowledge of two disparate conceptions is at all possible, those two conceptions are the same.
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We can never have an appearance from nothing. It must come from something (Kant's statement) — Arthur Rupel
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This is correct, as shown here: “...For, otherwise, we should require to affirm the existence of an appearance, without something that appears—which would be absurd....”. In other words, there are real objects external to us. That’s all he is saying. Kant was, after all, an empirical realist.
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and that something is the "thing in itself," — Arthur Rupel
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Only in the most liberal interpretations. When you’re talking about Kantian reason, all you can talk about is that which is internal in us, and nothing whatsoever concerning that which is external to us, except for the fact that’s its there. It follows that appearance is not so much the thing-in-itself, which is external, but that which is passed on from perception, which is internal. Thus, appearance, in and of itself, simply stands for that “something” that has caused perception to react to an affectation on it.
Properly speaking, the “thing-in-itself” is a term of knowledge, not of cognition. Think of counting to ten in the most logical way, in which you start at one. If knowledge is the ten, then the affect on perception is the one. At one, the “thing-in-itself” has no meaning. At ten, what we know is what reason has told us, and reason only tells us anything, by means of itself. That which affected our senses, that which appeared to us, tells us nothing at all about itself, other than it is there. In effect, what we know, is a determination from appearances alone, if for no other reason than that’s how the human cognitive system works. Which of course, has always begged the question.....what tells us what we know from appearance is not exactly the same as what we would know about the thing that appeared. Such may indeed be the case, but in this particular speculative metaphysics, if reason is the source of knowledge, the thing-in-itself cannot be, because if we had two sources we would have no means to determine which was correct in the event of a conflict between them.
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one view of noumena. — Arthur Rupel
Yeah, I suppose it could be one view, but it most certainly is not Kant’s view. One of the greatest feats of Kantian theoretical epistemology is its completeness, meaning that guy had an answer for every-damn-thing. Well, if there are only two possible sources of knowledge, knowledge of the empirically real and knowledge of the rationally thought, and if the “thing-in-itself” is proved to be a limitation on the former, then there absolutely must be a limitation on the latter, if only for the sake of logical consistency. Empirical knowledge is derived from sensibility, rational knowledge is derived from the understanding. Therefore, that which limits rational (a priori) knowledge must be a limit on understanding. Kant limits the faculty of understanding by positing its pure conceptions, called categories, can only be applied to phenomena, which, from the above, are shown to come from the faculty of intuition. But noumena are merely thought in general a priori, which means they have no object of intuition to represent them, which means the categories cannot be applied to them, which means we can have no cognition of them, hence they are meaningless. But......what are they, if they can be thought? We can’t say. We could say, if we had a mode of non-empirically grounded intuition to which the categories could be applied, but we don’t, so understanding is brought up short. He goes on to grant the possibility of “intellectual” intuitions, but nonetheless, the categories still couldn’t synthesize a mere intellectual object into either an empirical or rational cognition without devolving the entire system into an irreconcilable inconsistency.
All this because of the common misunderstanding, that because both the thing-in-itself and noumena are unknowable, they are the same thing. They are very far from the same thing, and even though Kant himself confuses everybody by actually calling them out identically, within the context of his doing that, he does not mean them to be the same thing. Thought of the same way, perhaps, but never thought of as being the same thing.
So.......
how do we get phenomena from noumena. — Arthur Rupel
By having a faculty of intuition other than the one we actually have, which makes explicit....we don’t.
“......But if we understand by it an object of a non-sensuous intuition, we in this case assume a peculiar mode of intuition, an intellectual intuition, to wit, which does not, however, belong to us, of the very possibility of which we have no notion—and this is a noumenon in the positive sense of the term. The doctrine of sensibility is also the doctrine of noumena in the negative sense, that is, of things which the understanding is obliged to cogitate apart from any relation to our mode of intuition, consequently not as mere phenomena....”
Print reference: CPR, B307, 1787, in Meiklejohn, 1855, B307 slightly re-worded in Kemp Smith, 1929, but irrespective of translator, Sec I, First Division, Book II, Chapter III.
Good luck and have fun with it.