What is "intuition" for Kant?

Question

Intuition appears to be a relatively abstract concept, an incomplete cognition, and thus not directly experienceable. Kant says that all knowledge is constituted of two parts: reception of objects external to us through the senses (sensual receptivity), and thinking, by means of the received objects, or as instigated by these receptions that come to us ("spontaneity in the production of concepts").

(The above is entirely based on Critique of Pure Reason, Paragraph 1, Part Second, Transcendental Logic I. Of Logic in General)

He says that in order to have a cognition we need both intuition and conceptions. Is intuition, then, some kind of highly momentary un-reflected state of passive receptivity? Is it more of a theoretical concept which does not form an experienceable part of cognition?

Even the second part of the process (conceptual part) he describes in the telling phrase: "spontaneity in the production of concepts". If concepts are also occurring spontaneously, without much active, controlled thinking taking place, then is the entire knowledge producing activity very transitory as seems to be implied?

Answer 1

Not exactly. You are trying to map Kant into modern cognitive psychology, which is a natural thing to do, but can only give us an idea of what Kant might have been getting at from our modern perspective, not how he actually thought about it. In his own mind he was not working with introspective data, nor was he trying to build a dynamical model of mental cognitive processes. In the Preface to Metaphysical Foundations of Natural Science he explicitly writes that "the empirical doctrine of the soul” will never be "a properly so-called natural science", see Steinert-Threlkeld's Kant on the Impossibility of Psychology as a Proper Science.

In his mind Kant reasoned from characteristics of knowledge (of the kind available to us) to functional elements that must be in place to make it possible, these are his signature "transcendental arguments". These elements included sensibility, productive and reproductive imagination, understanding, reason, the cryptic "transcendental unity of apperception", and of course the a priori forms of intuition. Characterizations like "highly momentary un-reflected state of passive receptivity", or anything else like that, would sound insufferably psychologistic to Kant. "Spontaneity" is not anything psychologistic either, it refers to the fact that concepts are not read off from empirical input, or seen through intellectual mindsight, as most philosophers thought before him, but rather are produced by the subject herself, as part of those functions necessary for having knowledge. Kant does mention in Critique of Pure Reason (A78/B103) that productive imagination is a "blind but indispensable function of the soul, without which we should have no knowledge whatsoever, but of which we are scarcely ever conscious" (A78/B103), but he is far from concerning himself with whether it is controlled, transitory, etc.

Now what of intuition? It helps to put it into the context of Kant's time as well. It has little to do with the modern colloquial meaning, something like what Peirce called "instinct for guessing right". According to Adams, the Latin term intuitio was introduced by scholastic authors:

"[For Duns Scotus] intuitive cognitions are those which (i) are of the object as existing and present and (ii) are caused in the perceiver directly by the existing and present object. [...] According to Ockham, an intuitive cognition of a thing is that in virtue of which one can have evident knowledge of whether or not a thing exists, or more broadly, of whether or not a contingent proposition about the present is true."

But by the time of Kant belief in such special faculty of immediate knowledge was severely undermined by nominalists and then empiricists. Neither Platonic/Aristotelian theories of direct perception of forms, nor "rational intuition" based on "innate ideas" a la Descartes, etc., had much credibility left. So Kant's notion of intuition is much reduced compared to its predecessors. Here is Hintikka's description of how Kant understood intuition:

"The only notion of intuitiveness that was alive for him was a diluted one amounting to little more than immediacy. But Kant gave this immediacy a special interpretation. He thought that our representations (Vorstellungen) could relate to objects in two different ways, either indirectly, via the general characteristics (Merkmale) they have, or else directly, as particular objects. Thus intuitiveness came to mean for Kant simply particularity...

As a consequence, Kant does not normally speak of intuitive knowledge. Intuitiveness is for him in the first place an attribute of representations (Vorstellungen), not of items or kinds of knowledge. For him, intuitions in the minimal sense of the word are nothing but singular representations in contradistinction to general concepts. Intuition was not a source of truths or insights, but merely the medium of representing particulars, and intuitive knowledge was for him, not knowledge proclaimed to me by a special oracle called intuition, but simply knowledge obtained by means of such representations, especially by the method of exhibiting general concepts by means of their particular representatives... There was for Kant no definitory link between intuition and sense-perception or imagination. Purely symbolic algebraic symbols could be "intuitive" merely because they represent particular numbers."

Kant himself talks not as much of intuition being the medium of representing particulars ("undifferentiated manifold of sensation" is more of that for the sensory cognition) as of individual intuitions as particulars there represented. The intuition/concept duality is explicitly analogized in the Amphiboly of Concepts of Reflection to Aristotle's matter/form. So it is as hard to put a finger on what intuitions by themselves are as on what Aristotle's prime matter/pure potentiality might be, divested of all form. In CPR A68/B93 we read that "whereas all intuitions, as sensible, rest on affections, concepts rest on functions", which suggests that intuitions might be akin to what is now called "qualia", but without the subjective/psychological connotation. However, as Pippin remarks in Kant on Empirical Concepts, the role of intuitions remains murky. He does try to offer a reconstruction:

"That is, relatively little attention, either in Kant or in the literature, has been devoted to the positive details of his theory of empirical knowledge, the exact way in which human beings are in fact ‘guided’ by the material of sensible intuitions... Any intuited ‘this’ can be a ‘this-such’ or ‘of-a-kind’, or, really determinate, only if a rule is applied connecting that intuition (‘synthetically’) with other intuitions (or remembered intuitions) ‘in one consciousness’. Or, finally, to say that ‘one’ concept includes or refers to ‘many’ representations is not to assert a problematic relation between one abstract entity (like a universal) and many other entities. It is only to express that a rule can be applied in many different instances of intuiting. More generally, we can say that concepts thus do not refer to anything; they classify conceptual activities and are thus used universally and do not name a universal.’"

Answer 2

Intuition is an a priori precondition of sensible experience. As far as I can tell, Kant intends that it function synthetically on the fly. Kant talks somewhere in the B-edition, I believe, about a community of apperception preceding a unity of appreciation.

Answer 3

It seems that since I added my succinct answer, this post has been filled by pretty much spam. I'd dissuade most of these posters, who somehow have accrued all these internet "points", to invoke Heidegger, psychology, even notions such as "biophysical ground". Not only are they wrong in terms of understanding Kant, but it's better to stick to the text.

The other thing that I'll add is that there's something to be said about tracing the evolution and etymological history of a philosophical term of art such as intuition, as another poster has done, but this kind of investigation is best done after you've contended with the text in its entirety. It's better to understand Kant in his own terms (in so far as this is possible), and only afterwards expand into intertextuality. Most of the people who have tendered answers you can tell haven't read Kant in full, but are eager to flaunt their knowledge.

One might try out a functional-role interpretation, here, saying that a Kantian intuition is anything that provides for synthesis. Unfortunately, in the Critique of Practical Reason, Kant says that we know the form of the categorical imperative synthetically a priori but without intuition, which seems to undermine the given interpretation (or indicates that Kant undermined his own presentation, maybe).

This is a load of nonsense, and betrays a complete lack of understanding of Kant! You'd know that regulative principles, like the categorical imperative, don't require intuition. To bring morality into this discussion, you'd need to engage with what Kant means by autonomy, which is akin to the will determining itself. The autonomy of the will does not fit in his transcendental idealism. But he argues in his solution to the 3rd antinomy that autonomy is logically possible, that is to say, that assuming the truth of autonomy and transcendental idealism does not entail a contradiction.

intuition is whatever is involved in justifying existence (or rather substantively modalized) claims (and so the Cartesian ontological argument is invalidated as adverting insufficiently to existential intuition).

No! Existence for Kant is a posteriori. Intuition is necessary for the synthesis of objects, but does not confer existence. This does mean that Kant does not predicate existence to mathematical objects. If pure intuition justified existence claims, then you could have a synthetic a priori proof for God.

Now (4) leads into the question of what Kant meant by intellectual intuition. Sensibility's mark is its passivity or receptiveness; sensation is something that happens to us. Sensation can then in a sense(!) cause intuition (be a (partial) occasioning cause of this

No! Sensation does not "cause" intuition for Kant. Sensation is the marriage of pure intuition and the matter of perception. Intuition is present a priori as the form of receptivity, which spatio-temporally organizes information coming from the senses. Nothing could be presented unless under the necessary conditions of receptivity, i.e. pure intuition.

Answer 4

I'm going to try to give you answer that tries both to add to the previous but also aims to be more succinct so that you have a more thorough one and a more pithy one.

Intuition, for Kant, is the form of sensibility. Sensibility defines as the ability of the mind to receive 'perceptual content' (my own term: Kant uses various terms, like the matter of appearance, sensation etc.), that is, to use Kant's own term, receptivity. Sensibility, therefore, is characterized by receptivity. But in order to be able to receive any content, that content must conform to the mind's conditions of receptivity. Those conditions are the pure intuitions of space and time. Therefore, intuitions are pure, that is, a priori (given prior to experience), and exactly two: space and time. Kant reserves the term 'intuition' because space and time are non-conceptual, that is, not concepts! They are the form of sensibility, namely the a priori component of receptivity. The desk that you see in front of you, insofar as the faculty of sensibility can present taken in isolation from full-fledged cognition (which will require the understanding), does not contain any concepts.

Pure intuitions are thus the conditions under which anything can be 'presented' as appearance at all. Kant argues that unless the mind formally conditioned empirical input to be spatially and temporally ordered, appearances could not be "presented". You can think of "presented" as equivalent to "perceived". However, in some passages, Kant reserves the term "perception" for the marriage of appearance with "consciousness" (A 120). Colloquially though, you can think of appearance as organized perceptions without conceptual synthesis, which will come together in Kant in his transcendental unity of apperception, where three distinct acts of synthesis come together in one consciousness.

So, in a nutshell, intuitions are neither appearances nor concepts, they are forms of sensibility. Appearances are always the combination of the matter of sensible content with the pure conditions of that content's receptivity: the intuitions of space and time. Still, what the heck are intuitions? While this is the answer as far as Kant's textual evidence provides, it's still unsatisfactory in and of itself, so you'd be right if you thought that the notion of intuition remains murky. To get deeper into the weeds, you'd have to look at scholarship on the definition of intuition and disagreements that persist about it.

Answer 5

Two remarks: First, could you add the citation for the quote of Kant in the middle of the post? Second, I miss a definite answer of what intuitions are. I guess it is rather clear from the famous "Concepts without intuitions are empty, intuitions without concepts are blind" that intuitions are representations [Vorstellungen] of the manifold of sensibility that are conceptually structured by imagination and understanding through the categories. This could work as hypothesis for a positive determination, couldn't it? – Philip Klöcking

♦

I just wanted to reply to this. You're not wrong in that second last sentence as a characterization of how everything, more or less, comes together in cognition for Kant. But that's not a definition of intuition. Intuition is only a part of that grand unified synthesis in one experience. Intuition is the pure component of sensibility. Categories are the pure component of the understanding. The imagination, a fraught concept in Kant which I won't go into, is the midwife between the two. All come together in the transcendental unity of apperception.

So to return to Kant's famous quote: "concepts without intuitions are empty, intuitions without concepts are blind" -- Kant will argue that concepts must conform to spatiotemporal constraints to synthesize objects. The concept of the soul, for example, has no spatiotemporal correlate, and is therefore "empty". On the other hand, a pure or empirical spatiotemporal manifold (pure: triangle in mind, empirical: a chair) without conceptual synthesis, does not yield cognition of objects, hence blind. No judgements/propositions will be possible. This is what he means. The marriage of pure intuitions with pure concepts (which are the categories) will yield Kant's famous synthetic a priori judgments. Synthetic a priori rules will also form the condition of possibility for any possible experience.

Answer 6

I'll just add this regarding one form of intuition, from the Critique of Pure Reason 1781:-

4. Provisional explanation of the possibility of the categories as a priori cognitions.

There is only one experience, in which all perceptions are represented as in thoroughgoing and lawlike connection, just as there is only one space and time, in which all forms of appearance and all relation of being or non-being take place. If one speaks of different experiences, they are only so many perceptions insofar as they belong to one and the same universal experience. The thoroughgoing and synthetic unity of perceptions is precisely what constitutes the form of experience, and it is nothing other than the synthetic unity of the appearances in accor­dance with concepts.

A111

Unity of synthesis in accordance with empirical concepts would be entirely contingent, and, were it not grounded on a transcendental ground of unity, it would be possible for a swarm of appearances to fill up our soul without experience ever being able to arise from it. But in that case all relation of cognition to objects would also disappear, since the appearances would lack connection in accordance with universal and necessary laws, and would thus be intuition without thought, but never cognition, and would therefore be as good as nothing for us.

"Intuition without thought" (gedankenlose Anschauung) would be the myriad sensory reception of experience, except it is handled unconsciously so it appears as nothing, and yet it is the biophysical ground for cognition. But biophysics belongs to practical reason, not pure reason ie phenomenology, so by the latter it is not discerned. (Excuse me if I'm speculating beyond my sketchy knowledge.)

As discussed on Heidegger Forum 2022, it is aligned with Being in Heidegger's oeuvre, which also doubles-up as nothing.

The nothing is the "not" of beings, and is thus being, experienced from the perspective of beings. (Pathmarks p.97)

ie Being is not beings. Likewise intuition without thought is not thought experience. In both Kant's and Heidegger's cases add time and cognition to produces the 'beings', the things in experience. Thus is the phenomenological container put on the source of beings.

Answer 7

One might try out a functional-role interpretation, here, saying that a Kantian intuition is anything that provides for synthesis. Unfortunately, in the Critique of Practical Reason, Kant says that we know the form of the categorical imperative synthetically a priori but without intuition, which seems to undermine the given interpretation (or indicates that Kant undermined his own presentation, maybe).

Or another functional-role interpretation could be: intuition is whatever is involved in justifying existence (or rather substantively modalized) claims (and so the Cartesian ontological argument is invalidated as adverting insufficiently to existential intuition). More on this in a little.

Back in about the middle of the first Critique, Kant does write:

We are in no want of words to denominate adequately every mode of representation, without the necessity of encroaching upon terms which are proper to others. The following is a graduated list of them. The genus is representation in general (repraesentatio). Under it stands representation with consciousness (perceptio). A perception which relates solely to the subject as a modification of its state, is a sensation (sensatio), an objective perception is a cognition (cognitio). A cognition is either an intuition or a conception (intuitus vel conceptus). The former has an immediate relation to the object and is singular and individual; the latter has but a mediate relation, by means of a characteristic mark which may be common to several things.

I will avoid quoting directly from the section on the anticipations of perception except to note that he says that "sensation in itself is not an objective representation, and in it is to be found neither the intuition of space nor of time [emphasis added], it cannot possess any extensive quantity, and yet there does belong to it a quantity (and that by means of its apprehension, in which empirical consciousness can within a certain time rise from nothing = 0 up to its given amount), consequently an intensive quantity."

So thus far:

1. Intuition is a sort of reciprocal of conception.
2. Intuition is involved in synthesis.
3. Intuition is the sufficient justifier (when available) of (categorical) existence claims.
4. Intuition is not sensation, neither in the way of all intuitions being sensations nor indeed in the way of sensation at all being intuition (as such).

Now (4) leads into the question of what Kant meant by intellectual intuition. Sensibility's mark is its passivity or receptiveness; sensation is something that happens to us. Sensation can then in a sense(!) cause intuition (be a (partial) occasioning cause of this, that is); but intellection is essentially proactive (Kant's preferred description is "spontaneous"), and so intellectual intuition is active intuition. Closely related, if not identical, to intellectual intuition is intuitive understanding:

For if I cogitate an understanding which was itself intuitive (as, for example, a divine understanding which should not represent given objects, but by whose representation the objects themselves should be given or produced), the categories would possess no significance in relation to such a faculty of cognition.

Kisner[21] starts out by mentioning recent analysis of this topic:

There does not seem, then, to be an entirely stable consensus about what intuition is, since:

5. Intuition has both an empirical (receptive) and intellectual (active) form.

... is also a not-fully-understood moment in Kant's implicit definition.