Transcendental Idealism

I’ll start from Kant’s thesis that a transcendental idealist is an empirical realist. In the above graphical schema this is a complete inversion of Descartes position. I’ll examine the transcendentally ideal first.

What’s Kant’s version of having an idealist metaphysical attitude towards the conditions of possibility for the objects of sense (time and space)? Unlike Berkeley, space and time are not ideal properties, but ideal forms of experience in general.

What Descartes discovered when he realized he could not abstract from an object its extension in general, despite being able to abstract its colour, and hardness, and particular shape, and so on, was not a necessary ‘core’ of things in themselves, but the discovery of the formal frame of our experience. The way in which the objects of experience appear to us is as extended (thus ordered in space). Our not being able to abstract this spatiality from them says more about what needs to be the case (the conditions of possibility) of our experiencing them, rather than how they are in themselves.

This may be clearer if we demonstrate the insight in a more limited domain: our visual experience of colour. Now, colour is a ‘dimension’ in the technical sense of that term, as can be evinced by its use to replace a spatial dimension in topographical maps. These maps are obviously only of use to creatures whose have vision (and, to understand a particular coloured topographical map of ours, they would also need a similar structure of vision to ours). Colour is a dimension of vision. In fact, it is arguably the dimension of vision.

When Kant says that such and such is a necessary transcendental form of something, we can read this as saying that such and such is a constitutive dimension of something. If we limit ourselves to vision as such, we realize that the dimension of colour is not something contingently apprehended by creatures with vision, it is the necessary condition of possibility of vision itself. We don’t ‘learn’ to see colours in general by looking at colours, because if we couldn’t see colour in general already then there’d be nothing to look at. Kant uses this exact argument apropos space: we couldn’t gain an understanding of space by experiencing spatial relations, because such an experience presupposes such an understanding (A23|B28).

Now, a dog, a mantis shrimp, and a human, may have their ‘colour spaces’ populated by vastly different diversities of colour, but, insofar as they all possess the ‘faculty of vision’, colour is a necessary dimension around which this vision is structured, even if it’s merely binary-monochromatic. Notice how there being the necessity of colour (given vision) tells us nothing about the particular colours of empirical objects. All we know is that if we can ‘see’ something, then it is registering somewhere in the dimension of ‘colour’, because that what to ‘see’ means, and, indeed, that it is all that colour in general is.

In fact, Berkeley was as close to this transcendental insight concerning colour as Descartes was concerning extension. He argued, against Descartes, that it is not the case that one can abstract colour from extension (Downing, 2011). The notion of an extended thing that did not register along the dimension of colour was inconceivable. When we imagine a ‘pure extended triangle’ we can imagine no such thing without it possessing some colour.

The entire Kantian innovation can be drawn back to this: Descartes and Berkeley both seem to agree that if some property-in-general could not be abstracted from a thing, this thing possessed this property-in-general necessarily and constitutively, it was a part of its fundamental essence. Where they disagreed was just how far the abstractive acid could distil essence (what properties could be abstracted). However, both were beholden to the scholastic-Aristotelian view that properties inhered in substances despite how far they had distanced their positions from other scholastic assumptions. Kant merely takes the final step: the impossibility of abstracting those final few (or single) properties should not be taken as having arrived at the substantial core of the thing, its essence, but, rather, should be taken as those properties being the fundamental dimensions through which the object is given to us in experience. Space and time are not properties, relations, essences, or ideas, they are the conditions our cognition places on the possibility of experience itself. And just like in the example of colour where a dog and human may disagree about a particular case of colour, but must, necessarily, both be seeing in terms of colour in general to see anything at all, likewise in the case of any experiencing creature, it must be necessarily experiencing in terms of time and space. Two vastly different creatures could disagree about particular spatial-temporal cases, but if they are experiencing anything at all, they are experiencing things spatially and temporally.

Scaling up from colour and vision, to time and space and experience in general, is quite mentally taxing. An example may be useful. Imagine pitting two chess playing AI’s against each other. If we are not interested in observing the progress of the game, there is no need to represent the board and its pieces. If the two AI’s shared their information perfectly, and the computer was sufficiently powerful, we could get the results of a thousand games (with a record of all moves ‘played’) at the press of a button. The amalgamated AI (it would in fact be singular and just playing itself), in not having to ‘represent’ the game space to itself (including not representing two sides as ‘opponents’, by sharing all information), can calculate n number of matches purely logically. The only time requirement, then, is the requirement of the hardware we as experiencing beings have constructed. A God, given the source code, could calculate the outcomes of an infinite number of matches instantaneously. If the game need not be ‘experienced’ by some being like us, there is no need for spatial-temporal limitations, considerations, or instantiation.

So, just like how it makes no sense to talk about what colour things are in themselves, beyond the domain of creatures with vision, it also makes no sense to talk about where and when things-in-themselves are, beyond the domain of experiencing things that represent them.

Empirical Realism

So far these considerations could seem to be merely shoring up dogmatic idealism. The second half of Kant’s position remains to be shown — how one can be an empirical realist when the conditions of possibility of empirical experience are themselves ideal.

Kant’s solution begins with a terminological distinction: inner and outer sense. This is an empirical distinction (signified by the ‘sense’), not a transcendental one. So, all it amounts to saying is that of all of the things we are conscious of, that we have representations of, some of them appear to be sensed within us, and others are sensed as being ‘out there’. ‘Out there’ should not be taken to mean “beyond our representations”, but much more simply, as being represented as though they are ‘over there’, ‘on the other side of my eyelids’, and so on. No transcendental claim is being made, just a taxonomy of different kinds of ‘internal’ representations.

Now, what is it that allows our representations to be ‘tagged’ or ‘tokened’ as being inner or outer? That is, what distinguishes this seeming towards our myriad of representations? Well, those that are represented through the form of space (itself ideal) are tagged ‘outer’ and those represented wholly through the form of time (also ideal) are tagged ‘inner’. All of this, so far, is a play of terms. There is some empirical import in defining things this way, (it predicts that what people common refer to as uncontroversial examples of ‘inner’ mental states would be lacking in spatial determination, but have duration) but not much is being asserted metaphysically. Kant is not claiming that transcendentally ‘outer’ objects (objects beyond our representations) are spatial (as Descartes believed), merely we are prone to think of objects we represent as being ‘outside of us’ if they are represented in spatial terms.

From here, Kant then appeals to his earlier re-definition of matter from the opening paragraphs of the CPR:

“The effect of an object on the capacity for representation, insofar as we are affected by it, is sensation. That intuition which is related to the object through sensation is called empirical. The undetermined object of an empirical intuition is called appearance… I call that in the appearance which corresponds to sensation its matter…” (Kant, CPR, A20|B34)

We need to follow all of these connections through. There are sensations, these are the name for what in our representations we receive completely passively. A representation that possesses some degree of sensation (this passive reception) is called an empirical representation (empirical intuition). These ‘empiricalized’ representations in general are called ‘appearance’. Now, in all of this appearance in general are traces of sensations (by above definitions), these traces are called “matter”.

Collins (1999) even argues that these ‘grains’ of matter that mark our empirical representations are direct cognitive contact with some transcendent object.

“he [Kant] is not saying that when we perceive, we are correctly inferring the existence of an object corresponding to an apprehended inner representation, … That is the insecure causal argument that Kant rejects. For him, when we perceive, the element of sensation is immediate cognitive contact with the outer object and cannot exist without the outer object” (p.77)

This is perhaps most clearly grasped when we think of touch. When I ‘touch’ an object I bring it into immediate contact with my whole biological sensory apparatus. The degree of sensation is in proportion to actual physical contact, mass, resistance, etc. There’s a final jump perhaps, where this contact goes from a physical collision to a ‘feels like’, becomes coated in a representation. However, at the core of that representation is the physical resistance of real objects, translated perhaps, but so minimally it becomes almost impossible for us to describe “resistance” in terms that don’t reference the sensation at all.

Matter is sensation. This is not just an arbitrary stipulation, or a sceptical confession that we cannot go from the existence of sensation to the existence of ‘external’ matter. Kant means it quite literally. If space is an ideal formal frame of experience, ‘external objects’ just become those objects of ‘outer sense’ who are defined by being composed of sensation that is organized within the ideal frame of space. Thus, the spatially organized objects of empirical intuition, as representations marked and composed of sensation, are as real as real can be. They are, by the definition of ‘sensation’ (given completely passively) independent of the cogito, who must undergo them, but they are played out in and experienced through an ideal representation of space. In fact, it is because the transcendental frame is ideal, is a representation, that the reality of empirical objects can be conceived and grasped.

“Every outer perception therefore immediately proves something real in space, or rather is itself the real; to that extent, empirical realism is beyond doubt, i.e., to our outer intuitions there corresponds something real in space.” (Kant, CPR, A375) “The real in outer appearances is thus actual only in perception, and cannot be actual in any other way.” (A376)

Kant seemed aware of how counter-intuitive this Copernican Turn is, writing in a footnote:

“One must note well this paradoxical but correct proposition, that nothing is in space except what is represented in it. For space itself is nothing other than representation; consequently what is in it must be contained in representation, and nothing at all is in space except insofar as it is really represented in it. A proposition which must of course sound peculiar is that a thing can exist only in the representation of it; but it loses its offensive character here, because the things with which we have to do are not things in themselves but only appearances, i.e., representations.” (A374–375)

What Kant is ‘playing with’ (insofar as this seems like a ‘trick’) is the content of our epistemological demands. What is it we are asking to know when we ask to know what really exists beneath any and all possible representations of a given object encountered in space? Presumably this question makes demands of the nature of the thing-in-itself. However, if we have followed Kant’s arguments in the Transcendental Aesthetic through, and thus grant the ideality of space and time as forms of experience, then it becomes unclear as to what this demand requires for its satisfaction. It is not just that the demand is unreasonable because we are unable to provide an answer (which is common way of reading Kant’s admonitions about the unknowability of the things-in-themselves), its that the demand cannot be satisfied by any solution. It is, in effect, senseless. Bennett (2016) makes a similar point about Kant’s position elegantly:

“If someone says seriously ‘There is no moon’, we may think he has some fancy about a permanent visual hallucination or a trick by the Martians … Suppose, however, that after walking on the moon he says: ‘I grant that the evidence so far — and perhaps all the evidence there could be — supports the lunar hypothesis; but there is no moon.’ We can no longer regard him as fanciful or sceptical, for now we do not understand what he says.” (p.24)

Or, take for example someone who asks what this particular pen is. We then list off every property the pen appears to possess, including its spatial dimensions, coordinates, and its temporal history, the molecular constitution of its plastic and ink, the names of the truck drivers who drove it from factory to warehouse and from warehouse to newsagent, and so on. The person then replies “But all of that is just how it appears in empirical representations to those beings for which things appear. But, what is it really in itself?” Kant’s reply is that this epistemological demand (which is the demand of scepticism) is entirely senseless and contradictory. To be real means to appear in empirical representations to those beings for which things appear. If you want to know what it (the pen) is really, well, there it is, take a look, it’s that thing there. That pen is not really something else, it is just that pen.