Noumenon

In metaphysics, the noumenon (/ˈnɒuːmɪnɒn/, from Greek: [εν]νοούμενον) is a posited object or event that exists without sense or perception.^[1][2] The term noumenon is generally used in contrast with or in relation to phenomenon, which refers to anything that can be apprehended by or is an object of the senses. Modern philosophy has generally been skeptical of the possibility of knowledge independent of the senses, and Immanuel Kant gave this point of view its canonical expression: that the noumenal world may exist, but it is completely unknowable through human sensation. In Kantian philosophy, the unknowable noumenon is often linked to the unknowable "thing-in-itself" (in Kant's German, Ding an sich), although how to characterize the nature of the relationship is a question yet open to some controversy.

Etymology

The Greek word νοούμενoν nooúmenon, plural νοούμενα nooúmena, is the neuter middle-passive present participle of νοεῖν noeîn "to think, to mean", which in turn originates from the word νοῦς noûs, an Attic contracted form of νόος nóos "perception, understanding, mind".^[3][4] A rough equivalent in English would be "something that is thought", or "the object of an act of thought".

Concept in pre-Kantian philosophy

The Oxford Companion to Philosophy proclaims "Platonic Ideas and Forms are noumena, and phenomena are things displaying themselves to the senses. [...] that noumena and the noumenal world are objects of the highest knowledge, truths, and values is Plato's principal legacy to philosophy."^[5] However, that noumena and the noumenal world were objects of the highest knowledge, truths, and values were disputed from the start, beginning with Democritus, his follower Pyrrho, founder of Pyrrhonism, and even in the Academy starting with Arcesilaus and the introduction of Academic Skepticism. In these traditions of philosophical skepticism, noumena are suspected of being delusions. Plato's allegory of the cave may be interpreted as an illustration of the noumenal/phenomenal distinction.

Classical Taoist philosophy was well aware of a similar concept, as expressed by its proverb "[phenomenal] Tao which can be spoken is not true [nomenal] Tao".

Kant's usage

Overview

As expressed in Kant's Critique of Pure Reason, human understanding is structured by "concepts of the understanding", or pure categories of understanding found prior to experience in the mind, and which make outer experiences possible as counterpart to the rational faculties of the mind.^[6][7]

By Kant's account, when one employs a concept to describe or categorize noumena (the objects of inquiry, investigation or analysis of the workings of the world), one is employing a way of describing or categorizing phenomena (the observable manifestations of those objects of inquiry, investigation or analysis). Kant posited methods by which human understanding makes sense of and thus intuits phenomena that appear to the mind: the concepts of the transcendental aesthetic, as well as that of the transcendental analytic, transcendental logic and transcendental deduction.^[8][9][10] Taken together, Kant's "categories of understanding" are the principles of the human mind which necessarily are brought to bear in attempting to understand the world in which we exist (that is, to understand, or attempt to understand, "things in themselves"). In each instance the word "transcendental" refers to the process that the human mind must exercise to understand or grasp the form of, and order among, phenomena. Kant asserts that to "transcend" a direct observation or experience is to use reason and classifications to strive to correlate with the phenomena that are observed. Humans can make sense out of phenomena in these various ways, but in doing so can never know the "things-in-themselves", the actual objects and dynamics of the natural world in their noumenal dimension - this being the negative correlate to phenomena and that which escapes the limits of human understanding. By Kant's Critique, our minds may attempt to correlate in useful ways, perhaps even closely accurate ways, with the structure and order of the various aspects of the universe, but cannot know these "things-in-themselves" (noumena) directly. Rather, we must infer the extent to which the human rational faculties can reach the object of "things-in-themselves" by our observations of the manifestations of those things that can be perceived via the physical senses, that is, of phenomena, and by ordering these perceptions in the mind infer the validity of our perceptions to the rational categories used to understand them in a rational system, this rational system (transcendental analytic), being the categories of the understanding as free from empirical contingency.^[11][12]

According to Kant, objects of which we are cognizant via the physical senses are merely representations of unknown somethings—what Kant refers to as the transcendental object—as interpreted through the a priori or categories of the understanding. These unknown somethings are manifested within the noumenon—although we can never know how or why as our perceptions of these unknown somethings via our physical senses are bound by the limitations of the categories of the understanding and we are therefore never able to fully know the "thing-in-itself".^[13]

Noumenon and the thing-in-itself

Many accounts of Kant's philosophy treat "noumenon" and "thing-in-itself" as synonymous, and there is textual evidence for this relationship.^[14] However, Stephen Palmquist holds that "noumenon" and "thing-in-itself" are only loosely synonymous, inasmuch as they represent the same concept viewed from two different perspectives,^[15][16] and other scholars also argue that they are not identical.^[17] Schopenhauer criticised Kant for changing the meaning of "noumenon". Opinion is far from unanimous.^[18] Kant's writings show points of difference between noumena and things-in-themselves. For instance, he regards things-in-themselves as existing:

...though we cannot know these objects as things in themselves, we must yet be in a position at least to think them as things in themselves; otherwise we should be landed in the absurd conclusion that there can be appearance without anything that appears.^[19]

..but is much more doubtful about noumena:

But in that case a noumenon is not for our understanding a special [kind of] object, namely, an intelligible object; the [sort of] understanding to which it might belong is itself a problem. For we cannot in the least represent to ourselves the possibility of an understanding which should know its object, not discursively through categories, but intuitively in a non-sensible intuition.^[20]

A crucial difference between the noumenon and the thing-in-itself is that to call something a noumenon is to claim a kind of knowledge, whereas Kant insisted that the thing-in-itself is unknowable. Interpreters have debated whether the latter claim makes sense: it seems to imply that we know at least one thing about the thing-in-itself (i.e., that it is unknowable). But Stephen Palmquist explains that this is part of Kant's definition of the term, to the extent that anyone who claims to have found a way of making the thing-in-itself knowable must be adopting a non-Kantian position.^[21]

Positive and negative noumena

Kant also makes a distinction between positive and negative noumena:^[22][23]

If by 'noumenon' we mean a thing so far as it is not an object of our sensible intuition, and so abstract from our mode of intuiting it, this is a noumenon in the negative sense of the term.^[24]

But if we understand by it an object of a non-sensible intuition, we thereby presuppose a special mode of intuition, namely, the intellectual, which is not that which we possess, and of which we cannot comprehend even the possibility. This would be 'noumenon' in the positive sense of the term.^[25]

The positive noumena, if they existed, would be immaterial entities that can only be apprehended by a special, non-sensory faculty: "intellectual intuition". Kant doubts that we have such a faculty, because for him intellectual intuition would mean that thinking of an entity, and its being represented, would be the same. He argues that humans have no way to apprehend positive noumena:

Since, however, such a type of intuition, intellectual intuition, forms no part whatsoever of our faculty of knowledge, it follows that the employment of the categories can never extend further than to the objects of experience. Doubtless, indeed, there are intelligible entities corresponding to the sensible entities; there may also be intelligible entities to which our sensible faculty of intuition has no relation whatsoever; but our concepts of understanding, being mere forms of thought for our sensible intuition, could not in the least apply to them. That, therefore, which we entitle 'noumenon' must be understood as being such only in a negative sense.^[26]

The noumenon as a limiting concept

Even if noumena are unknowable, they are still needed as a limiting concept,^[27] Kant tells us. Without them, there would be only phenomena, and since potentially we have complete knowledge of our phenomena, we would in a sense know everything. In his own words:

Further, the concept of a noumenon is necessary, to prevent sensible intuition from being extended to things in themselves, and thus to limit the objective validity of sensible knowledge.^[28]

What our understanding acquires through this concept of a noumenon, is a negative extension; that is to say, understanding is not limited through sensibility; on the contrary, it itself limits sensibility by applying the term noumena to things in themselves (things not regarded as appearances). But in so doing it at the same time sets limits to itself, recognising that it cannot know these noumena through any of the categories, and that it must therefore think them only under the title of an unknown something.^[29]

Furthermore, for Kant, the existence of a noumenal world limits reason to what he perceives to be its proper bounds, making many questions of traditional metaphysics, such as the existence of God, the soul, and free will unanswerable by reason. Kant derives this from his definition of knowledge as "the determination of given representations to an object".^[30] As there are no appearances of these entities in the phenomenal, Kant is able to make the claim that they cannot be known to a mind that works upon "such knowledge that has to do only with appearances".^[31] These questions are ultimately the "proper object of faith, but not of reason".^[32]

The dual-object and dual-aspect interpretations

Kantian scholars have long debated two contrasting interpretations of the thing-in-itself. One is the dual object view, according to which the thing-in-itself is an entity distinct from the phenomena to which it gives rise. The other is the dual aspect view, according to which the thing-in-itself and the thing-as-it-appears are two "sides" of the same thing. This view is supported by the textual fact that "Most occurrences of the phrase 'things-in-themselves' are shorthand for the phrase, 'things considered in themselves' (Dinge an sich selbst betrachten)."^[33] Although we cannot see things apart from the way we do in fact perceive them via the physical senses, we can think them apart from our mode of sensibility (physical perception); thus making the thing-in-itself a kind of noumenon or object of thought.

Criticisms of Kant's noumenon

Pre-Kantian critique

Though the term noumenon did not come into common usage until Kant, the idea that undergirds it, that matter has an absolute existence which causes it to emanate certain phenomena, had historically been subjected to criticism. George Berkeley, who pre-dated Kant, asserted that matter, independent of an observant mind, is metaphysically impossible. Qualities associated with matter, such as shape, color, smell, texture, weight, temperature, and sound are all dependent on minds, which allow only for relative perception, not absolute perception. The complete absence of such minds (and more importantly an omnipotent mind) would render those same qualities unobservable and even unimaginable. Berkeley called this philosophy immaterialism. Essentially there could be no such thing as matter without a mind.

Schopenhauer's critique

Schopenhauer claimed that Kant used the word noumenon incorrectly. He explained in his "Critique of the Kantian philosophy", which first appeared as an appendix to The World as Will and Representation:

But it was just this distinction between abstract knowledge and knowledge of perception, entirely overlooked by Kant, which the ancient philosophers denoted by noumena and phenomena. (See Sextus Empiricus, Outlines of Pyrrhonism, Book I, Chapter 13, ' What is thought (noumena) is opposed to what appears or is perceived (phenomena).' ) This contrast and utter disproportion greatly occupied these philosophers in the philosophemes of the Eleatics, in Plato's doctrine of the Ideas, in the dialectic of the Megarics, and later the scholastics in the dispute between nominalism and realism, whose seed, so late in developing, was already contained in the opposite mental tendencies of Plato and Aristotle. But Kant who, in an unwarrantable manner, entirely neglected the thing for the expression of which those words phenomena and noumena had already been taken, now takes possession of the words, as if they were still unclaimed, in order to denote by them his things-in-themselves and his phenomena.^[34]

The noumenon's original meaning of "that which is thought" is not compatible with the "thing-in-itself", the latter meaning things as they exist apart from their existence as images in the mind of an observer.

See also

• Anatta
• Condition of possibility
• Haecceity
• Hypokeimenon
• Ineffability
• Schopenhauer's criticism of the Kantian philosophy
• Transcendental idealism
• Unobservable
• The Void (philosophy)

Notes

External links

Look up noumenon in Wiktionary, the free dictionary.

• The surd of metaphysics; an inquiry into the question: Are there things-in-themselves? (1903) Paul Carus, 1852–1919
• Article from undergraduate journal Noesis