I know Kant says it. But he also claims that nothing else can be said about noumena, only that they exist. I seem to be strongly convinced that this statement involves a contradiction and therefore cannot have any proper meaning. My disagreement seems to involve the definition of the word "exist", not so much in how a particular person defines it, but what meaning it could possibly have. I guess I claim that the statement "noumena exist" attempts to give the word "exist" meaning that no word or concept can possibly have - meaning completely detatched from subjective phenomenal experience.

As a thought experiment: If we knew that that there was no other experiencing mind or sentience outside of earth, and we knew that all life on earth would end in one year, but we could build an underground facility that would reseed life on earth and thaw out embryos and restart human life on earth in 100 million years, I would leave behind our current astronomy texts because I would know that they would be just as applicable to the new remade sentient beings. Likewise with respect to math texts. So, I believe that the milky way and the operation of division would continue to exist while they were not being experienced, but "exist" in the sense that is informed by subjective phenomenal experience. They exhibit the phenomenon of existence.

I got the strong impression from my limited exposure to epistemology that all experience is of phenomena, and that all meaning is informed by experience, however indirectly. Do I have a misconception here, or is this view controversial? Kant seems to agree for the most part - this perspective would seem to be the reason why he asserts that no statement about noumena can be made - noumena, not being phenomena, are not experiencable. but he reserves that one word "exist". He must be implying that "exist" contains meaning which is not informed by phenomenal experience. Is there a debate on this topic?

It seems to me that the word "exist" refers to a phenomenon and is informed by my subjective phenomenal experience. When you say "Your car will continue to exist while you are unconscious" I will say "Yeah, I know what you mean!" but noumena are by definition not phenomena, and so unexperiencable, and incapible of exhibiting any phenomena. I would tend to include "existence" among the phenomena that noumena, by definition, does not exhibit. So, to say "Noumena exist" is like saying "that which doesn't exist, exists"

I'd be grateful for any perspectives or criticisms of my conceptions on this topic.

  • I think it might be worth adding that my mind is certainly open to the possibility that based on our experience and observations maybe it could be demonstrated that something that we could call "noumena" must exist. But if it could be demonstrated through reason, based on phenomenal experience wouldn't it then be a "phenomenon" too?
    – laertiades
    Jan 28, 2021 at 17:13
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    You are right that one can not apply the empirical/experiential sense of "exist" to the noumena, applying categories of experience beyond any possible experience is generally a mistake, according to Kant. However, noumena, like anything within or outside of experience, are still subject to abstract speculation and formal logic, so analytic reasoning is applicable to them, and taking phenomena as the premise one can infer "noumena exist" in the same detached abstract sense as "something is".
    – Conifold
    Jan 28, 2021 at 18:51
  • Thank you for that @Conifold. "something is" seems to have meaning to me and "noumena exist" doesn't. I have some further questions for anybody kind enough to respond: Would you say that the concept (of noumena) is analogous to imaginary numbers - Both having a definition and function in statements, but neither having an experiential source for meaning?
    – laertiades
    Jan 28, 2021 at 20:40
  • What would be the clearest complete definition of noumena? "That, without which, phenomena could not exist?" Do we need to accept any assumptions for this to have meaning? For example, we need to assume that everything has to have a cause, or source, or reason? Or, every thing assumes an other?
    – laertiades
    Jan 28, 2021 at 20:41
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    Noumena are not analogous to imaginary numbers. The latter have synthetic "pure intuitions" (hence experience) attached to them, like all mathematical entities, the former are empty concepts without any intuitions. Nor are they subject to the law of causality, which is also synthetic a priori. Officially, noumena are not so much mystical as just hollow, but you are right in a sense. Kant implied that the noumena have something to do with God, and his successors ran with it by suggesting that we have esoteric "intellectual intuition" (which Kant denied) that gives us glimpses of them.
    – Conifold
    Jan 29, 2021 at 0:02

1 Answer 1


I will offer a point of view informed by a branch of formal language theory that I was exposed to in computer science. From this point of view, ontologies are a matter of choice. English, of course, is not a formal language, but a natural language. But there may be certain "jargons" within English that are formal languages. That is, they use the same syntax, and vocabulary (or some subsets thereof) but in addition have certain precise syntactic and semantic rules. I think this is somewhat akin to Wittgenstein's "language games", though I am not a Wittgenstein expert.

By the statement "ontologies are a matter of choice", I mean that one can create a formal language in which various terms may be associated with the verb "exists", or which may be said to be "real", or "actual", or any variety of similar related terms. One can communicate using that language. Or one can choose another language in which a different set of terms may be associated with the words "exists" or "real" etc. Neither language is "right", they are just different tools that we may use.

One desirable feature of a language that we may look for in our choice of language is that it be sufficiently expressive. Another desirable feature is that it restrict our ability to utter things we don't find worthy of expression. "Nonsense" statements, or self-contradictory statements generally fall into that category.

In the language that you wish to use, at least for now, there are statements which are true. Those very same statements may or may not be true in another language. One of these statements that you have identified is

the milky way and the operation of division would continue to exist while they were not being experienced, but "exist" in the sense that is informed by subjective phenomenal experience. They exhibit the phenomenon of existence.

If you recognize that as a choice rather than as a more accurate statement about reality than some alternate expression, then you may come to see that whether or not "noumena exist" is also a choice. Would your language suffer by including among its true statements "noumena exist"? Possibly. But that really depends upon your priorities. If restricting "existence" to the "phenomenal" is important to you, then go for it. (Personally, that is not important to me.)

  • Interesting point. Thank you. Personally I prefer to think of my choice as expanding the "phenomenal" to occupy all of "existence", rather than restricting "existence" to the phenomenal. the latter giving the impression that I am small minded. But on a more serious note, surely we can say that some notions are just plain old false. For example, the notion of ether. Is it not possible that the notion of noumena will go the same way as the notion of ether, regardless of the language?
    – laertiades
    Jan 29, 2021 at 3:57
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    Physical theories generally provide for predictions. There are perhaps exceptions, but they do not occur to me off the top of my head. Physical theories that seem to predict particular outcomes, which outcomes don't come to pass tend to fall into disfavor. So, in many languages, these theories are said to be false. "noumena exist" or "noumena doe not exists" are statements which do not seem to have any predictive value, thus that particular road to preferring one over the other doesn't seem to be available. Jan 29, 2021 at 4:19
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    That's one way to look at it, but not "in the Kantian sense." Kant would probably rather have said that his ontology is true, not a matter of choice. Not necessarily a problem with the approach, but this answer is trying to evaluate Kant, not understand him
    – b a
    Jan 29, 2021 at 12:32
  • Could it be said that the statement "noumena exist" is a purely objective truth and therefore cannot have any meaning whatsoever to a purely subjective experiencer?
    – laertiades
    Jan 29, 2021 at 15:58
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    You might try the Russian Marxists. In particular Plekhanov, Lenin, and also Engels (Anti-Durhing) although he was not a Russian. Jan 30, 2021 at 1:36

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