Kant is specific when he tells us that the concept of noumenon is a “boundary concept”:
The concept of a noumenon is therefore merely a boundary concept, in order to limit the pretension of sensibility, and therefore only of negative use. But it is nevertheless not invented arbitrarily, but is rather connected with the limitation of sensibility, yet without being able to posit anything positive outside of the domain of the latter.1
This notion that noumenon is a limit concept, a negative limitation on sensible intuition which binds it to the circle of appearance and representation is a well known aspect of Kant’s system. He makes a point in acknowledging the limits of understanding and its use as empirical sensibility and that it “does not reflect on the sources of its own cognition” but is rather well suited to “determining for itself the boundaries of its use and knowing what may lie within and what without its whole sphere; for to this end the deep inquiries that we have undertaken are requisite.” (KL 8416) So Kant was already in agreement with those scientists who tell us that we might as well give up the notion of accessing the source of cognition since the very device (“cognition”) we would use to do so is blind to its own very real physical processes within the brain. Rather cognition was always built to confront the environment within which our evolutionary existence is tasked. No more, no less.
We’ll come to his definition and limitation of the Transcendental Analytic: That the understanding can never accomplish a priori anything more than to anticipate the form of a possible experience in general, and, since that which is not appearance cannot be an object of experience, it can never overstep the limits of sensibility, within which alone objects are given to us. (KL 8524) In other words we cannot step out of the circle of our sensible intuition to know things as they are in-themselves. Speculative realists want to call this the correlational circle.
Kant says it this way: “Thinking is the action of relating given intuitions to an object.” (KL 8530) Then will qualify it telling us that we have access not to the object-in-itself as it is, but rather we only ever have access to the thought of an object in general through the pure category in which an abstraction is made from any condition of sensible intuition as the only one that is possible for us. (KL 8532) It’s at this point that he introduces the division of phenomena and noumenon:
Appearances, to the extent that as objects they are thought in accordance with the unity of the categories, are called phaenomena. If, however, I suppose there to be things that are merely objects of the understanding and that, nevertheless, can be given to an intuition, although not to sensible intuition (as coram intuiti intellectuali), then such things would be called noumena (intelligibilia). (KL 8551)
The key here is “intuition”. He will say that sensible intuition is what we as humans are limited too, yet whatever noumena are they might be given to another type of intuition. Then he’ll clarify this telling us that all we have is the sensible intuition of objects that are formed as representations from appearances, and that we never have access to objects directly but only indirectly through these same representations which through inference suggest a “transcendental object” independent of sensibility.(KL 8569) But because all we ever have access too is the representation of this object as sensible intuition it “cannot even be separated from the sensible data, for then nothing would remain through which it would be thought. It is therefore no object of cognition in itself, but only the representation of appearances under the concept of an object in general, which is determinable through the manifold of those appearances.” (KL 8576)
Again Kant will stipulate that sensibility and its field, namely that of appearances, are themselves limited by the understanding, in that they do not pertain to things in themselves, but only to the way in which, on account of our subjective constitution, things appear to us. This was the result of the entire Transcendental Aesthetic, and it also follows naturally from the concept of an appearance in general that something must correspond to it which is not in itself appearance, for appearance can be nothing for itself and outside of our kind of representation; thus, if there is not to be a constant circle, the word “appearance” must already indicate a relation to something the immediate representation of which is, to be sure, sensible, but which in itself, without this constitution of our sensibility (on which the form of our intuition is grounded), must be something, i.e., an object independent of sensibility. (KL 8585)
This notion that if we are not to be caught in a circle of idealism, that appearance itself “must already indicate a relation to something” that is outside sensibility to which the appearance as representation refers as an “object independent of sensibility”. So in this sense Kant is a realist. This is where it gets tricky because its this acknowledgement of an independent object existing outside sensible intuition to which our representations as appearances refer Kant develops his concept of noumenon. And, as he’ll stipulate it “is not at all positive and does not signify a determinate cognition of any sort of thing, but rather only the thinking of something in general, in which I abstract from all form of sensible intuition.” (KL 8591) He’ll continue:
But in order for a noumenon to signify a true object, to be distinguished from all phenomena, it is not enough that I liberate my thoughts from all conditions of sensible intuition, but I must in addition have ground to assume another kind of intuition than this sensible one, under which such an object could be given; for otherwise my thought is empty, even though free of contradiction. To be sure, above we were able to prove not that sensible intuition is the only possible intuition, but rather that it is the only one possible for us; but we also could not prove that yet another kind of intuition is possible, and, although our thinking can abstract from that sensibility, the question still remains whether it is not then a mere form of a concept and whether any object at all is left over after this separation. (KL 8593-8602).
Humans he will tell us are only given sensible intuition, yet there must be “another kind of intuition than this sensible one, under which such an object could be given; for otherwise my thought is empty, even though free of contradiction.” As he states it sensible intuition “is the only one possible for us”, yet “another kind of intuition is possible” but to prove this is the problem as he suggests: “the question still remains whether it is not then a mere form of a concept and whether any object at all is left over after this separation”. This would be the Gordian knot of consciousness that would lead to so many blind alleys in the following two hundred years. In fact this is where philosophy is situated even today trying to get out of this box of sensibility. It might be that only the neurosciences might provide the clue. Or that we shuck the whole program of consciousness out the window and go with an asignifying form of materialist relations. Either way we’re stuck with this Gordian knot.
This is where he will once again reemphasize the concept of the noumenon, i.e., of a thing that is not to be thought of as an object of the senses but rather as a thing in itself (solely through a pure understanding), saying it is not at all contradictory; for one cannot assert of sensibility that it is the only possible kind of intuition. (KL 8621)
So in this sense the noumenon acts as a heuristic device to limit sensibility within the confines and boundaries of representational thought. Kant will conclude saying whatever the object is in-itself, the noumenon, “will always remain unknown to us, so that it even remains unknown whether such a transcendental (extraordinary) cognition is possible at all, at least as one that stands under our customary categories. With us understanding and sensibility can determine an object only in combination. If we separate them, then we have intuitions without concepts, or concepts without intuitions, but in either case representations that we cannot relate to any determinate object.” (KL 8660-8667)
Kant came up against a wall realizing that at least from his philosophical notions of sensibility, intuition, representation we could infer that something exists independently of us, but we could not know what this something is; and, yet, he did not exclude that some other type or mode of intuition might someday allow access to this realm of the noumenon. Of course later philosophers, and even Kant’s contemporaries would begin elaborate critiques and problematizations of this whole representational theory of sensible intuition. Even now this is still not concluded. Those within both Speculative Realism and certain materialist philosophies have been trying since Kant to break out of this prison of sensibility, seeking a way into this other type or kind of intuition and a way to think and know the noumenal.
Critique’s of kant’s category theory
Some like my friend R. Scott Bakker say we should forget philosophy and hand it over to the neuroscientists who are already discovering heuristical and hardware devices to do just that. The point is that maybe evolution did not require us to “know” what things are in themselves, but rather gave us other survival mechanisms which allowed us to represent only what the brain gives us after it filters out the excess of reality and delivers to us the fragments and images we need to get on with the tasks at hand. The neurosciences have already shown us that we never perceive reality directly, but only after the fact, after the brain has processed all the data and filtered what it concludes is pertinent. We know and see only the history of this decision.
Kant’s buried himself in feed-back loops of brain and consciousness, where the latter is always bound to what the brain constructs in way of representations of reality objects rather than the objects as they are in themselves; and, truth be told, the brain neglects what isn’t needed or necessary for the task in hand, and it decides even the task. So we are bound to a realm of information neglect, blind to our own knowledge not even knowing that what we know is but a miniscule of the data our brain happily filters out. What we finally perceive as an “object” is but a fragment of what the brain registers then gives us as representation. We don’t even know that we neglect what we don’t know and will never know. Some term this “meta-cognitive myopia“.
Klaus Fiedler describes “meta-cognitive myopia”, using a term once suggested by Robyn Dawes, is the phenomenon that people are pretty accurate in utilizing even large amounts of stimulus information, whereas they are naive and almost blind regarding the history and validity of the stimulus data. This uncritical reliance on the information given is the most conspicuous when the task context makes it crystal-clear that the stimulus data (Kant’s sensible intuition) should not be trusted. In the introduction, MM is located within a broader framework of meta-cognition research, and several examples are provided to illustrate the phenomenon. The central message is laid out that MM offers an alternative account of many biases in judgment and decision making, which have been traditionally explained in terms of capacity constraints, limited reasoning ability, motivational forces, or severely biased environmental input. The explanatory power of the MM construct, and its theoretical potential to predict new findings, is then demonstrated in a major review section with reference to five paradigms:
- inability to discard irrelevant information;
- utilization of selectively sampled information;
- conditional inference biases;
- sample-size neglect;
- and myopia for the impact of aggregation levels.
The final discussion Fiedler tells us is concerned with the learning origins of MM and the question of why evolution did not equip Homo sapiens with more effective meta-cognitive tools. An analysis of the costs and benefits will reveal that MM may serve important adaptive functions, and that eliminating MM may have maladaptive effects. Nevertheless, in the context of many real decision problems, the costs and irrational consequences of MM cannot be denied.
R. Scott Bakker in a post The Metacritique of Reason will argue that Kant and his followers up to our own time believe that philosophical reflection possessed the capacity to apprehend the superordinate activity of cognition, that it could accurately theorize reason and understanding. We now possess ample empirical grounds to think this is simply not the case. There’s the mounting evidence comprising what Princeton psychologist Emily Pronin has termed the ‘Introspection Illusion,’ direct evidence of metacognitive incompetence or neglect, but the fact is, every nonconscious function experimentally isolated by cognitive science illuminates another constraining/constitutive cognitive activity utterly invisible to philosophical reflection, another ignorance that the Intentionalist believes has no bearing on their attempts to understand understanding. For Scott we are blind to our own cognitive capacities because of medial neglect, the way structural complicity, astronomical complexity, and evolutionary youth effectively renders the brain unwittingly blind to itself. Medial neglect means that the limits of cognition systematically elude cognition. We have no way of intuiting the swarm of subpersonal heuristics that comprise human cognition, no nondiscursive means of plugging them into the field of the natural. And so we become a yardstick we cannot measure, victims of the Only-game-in-town Effect, the way the absence of explicit alternatives leads to the default assumption that no alternatives exist.
Yet, we must go back to Kant’s original statement which stipulated cognition of this nondiscursive domain as a boundary concept in my opening remarks where he makes it obvious that sensibility has limits and is bound by limited capacity to cognize due to a lack of access to the “sources of its own cognition”. Kant was well aware that we are encompassed by a world of information to which we have no access too, and was trying to build tools to access only what is “given” to us through the mental fabrications that the brain “sources” constructs through its mechanisms. I think if Kant lived today he’d admit just how little philosophers truly know, and how much we coming to realize that the little we do know neglects a great deal. We build reality out of bits and pieces of what the brain sees fit to give us in way of evolutionary processes of signifying and asygnifying systems. For Kant we are limited to the boundary zone beyond which the “pretension of sensibility” has little access:
The concept of a noumenon is therefore merely a boundary concept, in order to limit the pretension of sensibility, and therefore only of negative use. But it is nevertheless not invented arbitrarily, but is rather connected with the limitation of sensibility, yet without being able to posit anything positive outside of the domain of the latter.
- Kant, Immanuel (1998-01-13). Critique of Pure Reason (The Cambridge Edition of the Works of Immanuel Kant) (Kindle Locations 8633-8634). Cambridge University Press. Kindle Edition.