Immanuel Kant and the Noumenon

The Limits of Reason

Rational argument leads one to the conclusion both (1) that Time must have had a beginning and (2) that Time cannot have had a beginning.
Also (1) that Space must have a boundary, and (2) that it cannot have a boundary.
For when we try to imagine each wing of these contradictions, we find ourselves (at the same time) obliged to imagine its contradictory.
Rather similarly we find it equally possible to imagine (1) that we have Free Will, and (2) that we are causally determined.

Kant argues therefore that reason can lead us into contradictions. It is not therefore wholly to be trusted. Reality cannot wholly correspond to what reason tells us; and thus we cannot understand reality by the use of reason alone. We must therefore turn to experience.

The Limits of Experience

However, experience cannot provide certain knowledge of independent reality since (1) it cannot ever be confirmed that our sense-perceptions actually correspond in every detail to external objects. For we cannot step outside our own consciousness to check whether that consciousness is telling us ‘the whole truth and nothing but the truth’ about external objects.
It is in any case clear that what our senses tell us about the objects around us is (at least to a large extent) relative to our senses. For example, the colours that we see in external objects are phenomena which are relative to our brain- and/or mind-processes.
Secondly (2) we cannot form any conception of objects independently of the categories of experience and thought, and all of these are subject-dependent. For instance, when I see any object, I see it as existing in time and space, as being of a certain colour, uttering certain sounds, smelling in a certain way, etc. In short I cannot see it independently of my mental conceptions and of my nervous system.

Our perception of the world is thus limited. Behind appearances therefore there must lie things which, by definition, could never figure in experience.

Among the things we cannot ever directly perceive, but which we assume exist, are the laws of causality. According to Kant (who received this insight from Hume) the causal connexion between events is a thing that we suppose on the basis of observation and experience, certainly, but which we can never observe. It too lies outside experience.
It must however be supposed; for without assuming causal laws we could not make sense of the world. Similarly, without assuming the reality of space and time, the world would make no sense to us.

There are thus features of the empirical world which we must necessarily assume, though these are neither observable nor logically deducible. But we have to presuppose them because we would not ‘understand ’ the world without them. Certain preconditions have to be met before there can be any experience at all; these preconditions are constitutive of experience. Brian Magee puts this particularly clearly:

If we think in terms of the metaphor of catching things in the network of experience, these are the meshes of our nets. Only what can be caught in them is available to us. Anything that passes through them untouched will not be picked up by us, and nor will whatever falls outside our nets altogether. Only what our nets catch will be ours, and only what they can catch can be ours.

Scientific law itself is in exactly the same position as ordinary experience. It is subject to the limitations of human understanding; it is obliged to work with such basic categories of the understanding as causality, time, space, the existence of objects, etc. Scientific law simply cannot step outside certain preconditions. It therefore cannot possibly assert its own immunity to the arguments of Kant. It is as much a human creation as any other aspect of the human world.

We find therefore that there are limits to our understanding: what our physical & mental equipment cannot mediate cannot be experienced by us. This does not imply that what our physical & mental equipment cannot mediate cannot exist. Far from it. That would be a logical fallacy obvious to the most down-to-earth common sense; though it is one which unfortunately most materialist philosophers fell into long ago.

On the contrary there are no grounds whatever for pretending that reality must conform to the narrow limits of what we human beings can understand, grasp or know. Indeed, the whole of the preceding argument shows that we must admit that, since there are visibly limits to our understanding, the universe must therefore contain a reality or realities outside the possibility of these being known by human beings.

This independent reality outside the possibility of experience is termed by Kant the noumenon. He names it this in opposition to the ordinary world of appearances or of phenomena. ‘Since all forms of experience are inevitably subject-dependent, therefore whatever the nature of independent reality may be, it must lie permanently outside all possibility of experience.’ For experience is an ‘interpreter’s translation’ of reality: whatever the ‘real reality’ may be, when we experience it, it has been transformed by our experiential apparatus into something which expresses it differently, approximately and/or partially.

The Five Ms

We attempt to overcome these problems by pooling our isolated experiences (our subjective perceptions) in negotiated collective agreements as to ‘What appears to be the case to most of us.’ We call these agreements ‘objectivity’ – though they are actually purely derivative and provisional. So-called ‘objective fact’, whether in science or in everyday life, derives entirely from a pooling of individual subjective experience. We elicit from these claims to ‘objectivity’ our notions of the Four Ms, namely matter, materialism, models and mechanism. These notions are often thought to constitute a total explanation of the world.

It will be seen that the alleged totality of this explanation is a Fifth M. I.e. a Mistake.

The Evolutionary Argument

It has sometimes been argued that we must know the nature of the world with some accuracy, since our evolutionary survival depends on it. However evolution will ensure only the minimum amount of knowledge (whether real or approximate) which suffices for survival. It cannot entail total knowledge.

Ultimate Reality and Free Will

Must we accept that there is indeed such an unknown as Kant’s noumenon? One of Kant’s most famous arguments is as follows. We do (most of us) have moral concepts which we do (most of the time) regard as meaningful. But for the application of these concepts to be practicable, such terms as ‘right, wrong, fairness, duty, ought, should not, choice, integrity, honesty’ need to be meaningful. But for them to be meaningful, we human beings need to possess Free Will.

Unfortunately, if determinist philosophers are right, there is no such thing as Free Will. Everything (they say) is controlled by the blind forces of causality which, if you trace them far enough, will reach right back to the Big Bang. And those things which are not controlled by blind causality are the result of equally blind chance. Such materialist philosophers (and also certain materialist scientists) believe that we human beings are simply mechanical objects of an extraordinarily complex kind, and hence we must be subject to the universal scientific laws of causality. Our belief that we have Free Will is simply a prescientific delusion. I call this stance “vimfortism” (from the Latin vim = by force, and forte = by chance

But, says Kant, “Ought implies can.’ In short, unless we can act autonomously, our feeling that we ought to has no explanation. If it is impossible for me to act as I know I should, all morality is false.

Some determinists go so far as to say that, yes indeed, morality is meaningless. But do they act like that? Do they in fact disregard all fairness and justice; do they transgress all notions of morality, value or compassion? Has any of them ever faced up to what such behaviour would entail? Of how others would begin to treat them if they did behave in this way? Of how they themselves would begin to bitterly complain of ‘injustice’ and of ‘being unfairly treated’, and would appeal in short to precisely those values whose existence (in their comfortable lecture halls) they deny!

We must conclude that the determinists refute themselves. We must assert that ‘Ought’ does imply ‘Can’. Moral values must be real; and our ability to act morally must be real too.

This carries with it a devastating conclusion. Neither moral values nor Free Will can be explicable materially. They must lie quite outside the mechanically functioning laws of nature,’ i.e. outside vimfortism. It follows that some part of the normal human being lies, not inside the empirical world, but outside it. ‘In this way … the fact of the existence of a transcendental realm, a part of reality that is not the empirical world, is rationally demonstrable, and is therefore known by us with certainty.’

We thus find a part of the noumenon present in ourselves.

What lies in the Noumenon?

Free Will is intimately connected with consciousness. And since materialist explanations of consciousness fail, consciousness itself must also be part of the noumenon. What else, however, lies in the noumenon cannot be known, since it is outside our ability to experience it. We cannot know whether there is a God, or whether there is life after death. But equally we cannot know that there is not a God, or that we don’t have life after death. Both the position of the believer and of the atheist are equally a matter of faith or trust.

It is however evident, from the fact that (if you start from materialist and rationalist principles) Free Will is inexplicable, that the transcendental realm of the noumenon must be held to contain / constitute / possess certain attributes of a non-material and spiritual reality. The remarkable insights of Kant thus provide powerful support for an anti-materialist philosophy.


Guyer, Paul (1992) ed. Cambridge Companion to Kant, CUP. Cambridge & New
Magee, Brian (1997) Confessions of a Philosopher, Weidenfeld, London

5 thoughts on “Immanuel Kant and the Noumenon

  1. hi, a wonderful explanation of the noumenon. i didn’t quite understand it before, but your text helped me to understand it better. thank you. :)

      • In first place, sorry about the type in Giftwish (In Spanish the book has a different name, and I didn’t remember the correct English one)

        I was looking for you, because recently I was speaking with a friend about one of my favorite books ever: Giftwish. I read it twenty years ago, but I have not forget it. So, I though about to look for the writter and say: THANK YOU VERY MUCH. Twenty years ago my mother gifted me this book (one of the best gifts I have had ever), and in this moment I couldn’t imagine how much this book influenced me in the next years. Giftwish was my first experience in fantastic literature, and maybe, If I had read another book, I had not developed my love for literature, fantasy and legends so strong. Your book was really inspiring to me.

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