IV. Problems with the Functional Reading
1. Transcendental Architecture
For Kant, there are only two kinds of minds, discursive or concept using, and intuitive or one’s whose apprehension of objects is not mediated by sensibility and does not depend upon being affected from without in order to form thoughts of objects.
We are not in a position to have any insight into the latter, Godlike mind, so there is only one kind of mind that we can analyse, and only one kind of mind that has real philosophical significance, for Kant. Furthermore, Kant is interested in producing the single, unique schematic for the functions and structures of the discursive mind.
Functional analyses, by contrast, can be applied to a wide range of objects, and for any given type of output states, they have a great deal of latitude in how they characterize the processes that produced those outputs. A reverse engineering of the operations within the black box is possible for any system where we are informed about the input and the output states. And functionalism does not make any special distinctions about some kinds of outputs having more metaphysical or ontological significance than others. And it is this latitude that makes it possible for the functional labor to be distributed, apportioned, and divided in any number of ways provided that the same output states can be produced by the system. Many functionalists have looked to research in neuroscience about the architecture of the human mind for guidance in how to characterize the modules of the mind and the tasks that they perform.
Kant, however, believed that a mind of a reasoning agent (human or not) is a peculiar, philosophically unique subject of inquiry. Their mode of apprehension or representation of the world, unlike that of a purely intuitive intellect, is by means of concepts that must in part arise from their own devising. For Kant, the analysis of a concept using, judging consciousnesses reveals an elaborate transcendental architecture with broad metaphysical implications. The architecture itself is defined or fixed given the nature of the metaphysically unique status of being a mind that judges or thinks.
And Kant does not have functionalism’s latitude. He believes that there is one, unique description of the different faculties of a mind that can make empirical judgments.
We can see the importance and uniqueness of the mind in Kant’ system this way. He begins his inquiry in theFirst Critique
with the famous question, ‘How is metaphysics at all possible?’ The answer that becomes clear in the Transcendental Deduction and the discussion of mind that is under consideration is that metaphysics in Kant’s revised sense is only possible insofar as we find minds in the world. The mind itself is the cornerstone of Kant’s whole critical system. And it is the lofty status of this object of inquiry for Kant that stands in stark contrast to the tendency of contemporary functionalism to minimize the differences between minds and hearts and Coke machines and other ordinary objects that can be functionally characterized. Kant does not share functionalism’s drive to minimize the metaphysical entities and implications in our theory of mind. Nor does his theory allow for the rearrangement of any faculties, tasks, or the organisation of the structures of the mind.
2. The Division of Labor Problem
As we noted above, the only elements that are nailed down to reality in a functional explanation are the beginning states and the end states. And bridging the gap between them proves to be the biggest challenge for functionalists. It is hard to see how functionalism can provide any clear guidelines for the division of labor of the intermediate states except the actual configuration of the systems it analyses, whatever they may be. Presumably natural distinctions between the component parts or faculties and their relations will become evident upon investigation or construction of a functionalist system, or empirical data will suggest, a posteriori, how in fact, the different faculties are separated and how they interact. But the functionalist cannot count on such divisions to become clear from the functionalist analysis alone, and the functionalist cannot anticipate the divisions a priori. Potentially, there could be any number of schemes for the division of labor. As is evident when an Intel chip, an AMD chip, and a Macintosh chip all run different instances of the same program, the division of labor and the inner details of how the output states are generated, even in abstract functional terms, are dramatically different.
With vastly more complicated systems like human brains there will be numerous decisions to be made about how our functional hierarchy will be drawn. If we follow the construction of the human brain too closely, we are in danger of falling into the same kind of arbitrariness that type and token physicalist theories suffer from. We may produce an adequate of how the human brain functions, but we will be no closer to explaining in more general terms how it could be that non-human systems could possibly think. So by following the developments in neuroscience for details about how the brain works, functionalism is in jeopardy of making the very mistake that it set out to avoid.
Furthermore, the division of labor for the internal functions of computers, human brains, alien brains and so on is so different that a functional analysis that manages to accommodate them both is in danger of being abstract to the point of being vacuous, or useless as a means of providing valuable descriptions of the processing. So the fact that only the input and output states are nailed down to reality actually leaves the question of the division of labor painfully open.
The challenge for functionalism has come from disagreements about how the cognitive labor should be apportioned. Fodor points out that,
A census of faculties is not, in short, equivalent to an enumeration of the capacities of the mind. What it is instead is a theory of the structure of the causal mechanisms that underlie the mind’s capacities. It is thus perfectly possible for all hands to be agreed about what capacities a mind has and still disagree about what faculties comprise it.
And it is the disagreements about the faculties behind the capacities that have made progress difficult.
On Kant’s programme, these questions are resolved a priori. As he sees it, the scheme of faculties described in the Subjective Deduction is unique, and it is mandated by the very nature of cognition. The division of labor cannot be reapportioned as it can in functionalist analyses. Kant sees the components of mind that he has identified as so basic, that alterations of them or their tasks, or any redistribution of labor into another scheme would result in something that is not a mind at all. He believes his transcendental method has revealed the deepest organisational structures of mind. Functionalism, since it is only nailed down at the input/output periphery, has considerably more latitude in its division of cognitive labor.
3. Transcendental Method
On Kant’s view, the architecture of the mind that we settle on is not generated nor is it revised in response to the results of empirical investigation of human capacities, the findings of evolutionary biology, or the tenets of folk psychology.
In many cases, functionalists proceed in a bottom up fashion. That is, they scrutinize empirical data about human's cognitive performances - speech acts, verb tensing, binding visual data, and so on - to produce a scheme for the general functional organisation in the mind. When we discover different output performances, or if human cognition happened to be different, a different or emended account of functional features would be called for.
Kant, by contrast, has a top down approach. That is, Kant takes the performance of mind - judgment - as his starting point, and then analyses what the necessary presuppositions of such a performance must be. While the functionalist may render a variety of functional architectures to explain the transition from input state to output states, Kant believes that it is possible to derive the necessary and unique list of general functional requirements. So Kant's transcendental approach, if it succeeds, gives us an unalterable and crucial outline of the intermediate steps.
Another way to see the difference between the two projects is to recognize a strong or transcendental sense of a priori requirement in Kant and a weak or dependent sense. Let us say that when a contingently true feature of a cognitive system imposes constraint on the structure of that system, that constraint is dependently a priori. Experimental research on human infants reveals that we seem to have an innate preferential response to faces. Newborns respond more readily and with more attention to faces than to other objects.
I take it that this tendency is dependently or contingently a priori. There is nothing integral to having a mind or being able to judge that would require this preference, and humans could have developed without this tendency.
Similarly, it is dependently a priori that human visual systems can only detect electromagnetic radiation within the bandwidth of visible light. It is a contingent fact about human cognitive systems that this radiation is sensible; but we can imagine and perhaps even build a cognitive system in which some other part of the spectrum is detectable. Prima facie, it would seem that infrared or ultraviolet radiation or even echolocation
could serve as well to provide sensory data to a system. The fact that a system is a mind and is capable of thinking or making empirical judgments in Kantian terms appears to have no direct implication on at least some of the details of the sensory apparatus it employs. So when a system has a particular configuration, but it could have had another while still meeting the basic requirements of cognition, we can say that that configuration imposes dependently a priori constraints on it. As a result, objects for humans must possess some colour that is within the visible light spectrum. Significantly, Kant has very little to say about these sorts of variations.
When a constraint is imposed upon a cognitive system by the very nature of cognition, rather than the accidental configuration of some particular system, that constraint is transcendentally a priori for Kant. Using Strawson’s phrase, we can think of a mind as a thing that is capable of grasping or identifying objective particulars,
‘We think of the world as containing particular things some of which are independent of ourselves; we think of the world’s history as made up of particular episodes in which we may or may not have a part; and we think of these particular things and events as included in the topics of our common discourse, as things about which we can talk to each other’.
Thinking or judging objective particulars requires the application of concepts. Concepts are rules for organizing and sorting sensory data.
So it is transcendentally a priori true that a mind must have some means of receptivity, a faculty of sensation, that provides the data or content for judgment. Unless it has some means of input, it can make no judgments about objects, and cognition would be impossible. This is the level of a priori necessity he strives to demonstrate with regard to the possibility of experience. An examination of the peculiar, and contingent, features of human intellectual capacities can be no more than a ‘physiology of the understanding’ if we cannot determine the deepest and most general requirements imposed by the nature of cognition itself.
Kant seems to have these two senses of constraint in mind when he makes comments like the one at B 72,
There is, moreover, no need for us to limit this kind of intuition--intuition in space and time--to the sensibility of man. It may be (though we cannot decide this) that any finite thinking being must necessarily agree with man in this regard. Yet even if this kind of intuition were thus universally valid, it would not therefore cease to be sensibility. It would remain sensibility precisely because it is derivative (intuitus derivativus) rather than original (intuitus originarius) and hence is not intellectual intuition.
So we can say that a transcendentally a priori constraint on any derivative or discursive
consciousness is that it must have some mode of sensibility or other. Kant's suggestion here seems to be that space and time, as the particular modes of sensibility, are only dependently a priori conditions of human cognition. But any discursive mind must have a faculty of sensibility that will have its own forms or modes. Kant's commitment to the categories is stronger. They are the transcendentally a priori concepts for any discursive consciousness. (B 170)
With this distinction in mind, we are in a better position to see where the functionalist and Kantian projects diverge. The functionalist, particularly in experimental psychology, takes the human, monkey, or other lab animal as her subject matter. Analysis of test data reveals what sort of capacities the system has. Experiments with newborns and babies, for example, reveal the age at which babies begin to have expectations about the constancy of physical objects. In a familiar example, it was found that babies past a certain age are surprised to see a moving toy car disappear behind a box and not reappear on the other side. Before that age, and presumably before they have had enough interaction with physical objects, babies are equally surprised (or bored) by the car's disappearance as its reappearance. Such data gives us information about the functional relationship between sensory input states and the baby's output states, and development over time of cognitive structures. The surprise behaviour seems to be equivalent to a belief (in some sense of ‘belief’) that ‘physical objects don't just vanish into thin air’ or something to that effect.
The problem with the functionalist approach in the above case, Kant would say, is that it cannot distinguish between strong and weak senses of a priori constraints. Kant predicts that humans, like the older babies in the study, must conceive of objects as identical over time, with predictable, causal behaviour. The reason, says Kant, is that the very possibility of thought about objects requires it (whether or not humans in fact possess the ability.) The functionalist, however, cannot distinguish between this case where she has stumbled upon a strongly a priori feature of cognition and weakly a priori cases. Experiments also demonstrate that human stereovision has a blind spot. The presence of that feature does not signal some deeper part of the structure of consciousness. The functionalist cannot distinguish between the two cases, whereas Kant's transcendental approach can.
Now Kant would say that the experimental approach of the functionalist in the case above could, at best, determine theweakly
a priori constraints on the cognitive system. Unless we leave the experimental data aside, and step up to the level of transcendental analysis, we cannot uncover the requirements that cognition itself imposes. The top down and bottom up strategies have essentially different questions: What is the basic mental form that any thinking subject must take? Instead of: what explanation of mental states can we provide to connect observed input states with observed output states in humans?
That we possess a physical system capable of meeting the transcendental requirements of Kant's argument is a happy accident. If we had been something else, the functional analysis would have produced different conclusions altogether. (Not to mention that if we were not capable of thinking in the Kantian sense, we would be incapable of conducting functional analyses of anything included ourselves.) The functionalist might well respond that in practice, they do not have difficulty separating the important or essential components of cognition from the inessential ones - it is obvious to anyone who thinks about it that recognizing object permanence is vital and having a blind spot is not. But many of the features that we discover lurking in the recesses of the mind are not so obviously separable. And Kant, by taking the top down approach, has a great deal of guidance to offer here in prioritizing our research programme, focusing our attention on features that are essential to important cognitive functions, and streamlining our artificial intelligence research.
4. Ontological Commitment
For Kant, the ontological, the metaphysical, and the epistemological are intertwined. And the metaphysical and ontological implications of the activities of a mind that thinks cannot be extracted on Kant’s view as they can with functionalism that remains value neutral regarding the ontological composition of the system.
Kant has both negative and positive ontological theses that are bound to his account of mind. First, the negative: Since space and time are the forms of intuition provided by sensibility to intuitions and then judgment, Kant argues, perhaps mistakenly, that space and time cannot and are not properties of things in themselves. So the transcendental self, the unifying ground of synthetic activity, is not a spatial or temporal thing. That is why, in part, it is not a knowable, experiencable object for us. At best, we make a transcendental inference about its existence and its activities.
There is also a positive metaphysical thesis deeply connected to Kant’s theory of mind. Since space and time are the forms of our sensibility and they are constitutive of objects for us, the world of experience we inhabit must necessarily be a world of material objects. And as a member of that world, at least insofar as I have a body in that world that interacts with and sense material objects, I am/have a material body too. The possibility of knowing objects in the empirical world necessitates that I have a material body in it.
Kant explores the details of this implication in the Refutation of Material Idealism at B 274.
5. Non-Causal Account of Mental Functions
Another hallmark of functionalist theories is that they explain consciousness in virtue of thecausal
relationships of mental states to one another and to the input and output states of the system. One of Kant's arguments is that the discursive mind must necessarily conceive of its world as causally ordered. That is, the ordering of intuitions into causally related, empirical objects is theresult
of the cognitive process. The functionalist, however, presupposes a causal mechanism of some sort and seeks out the exact arrangement of causally related components.
6. The Reflexive Problem
And Kant has identified a unique problem that arises in the recursive project of trying to understand our own consciousness, and it is a problem that is not captured by the generic analysis tool provided by functionalism. Kant argues that since it is the mind that seeks to understand itself, and in effect subject itself to its own requirements for cognition, a barrier is created that prevents knowing the mind or the self ‘as it is in itself’.
For Kant the activity of a mind turning its own powers of thought onto itself creates a set of issues that are not paralleled in functionalist accounts. The self-analyzing itself imposes a cognitive barrier on what can be known about the process that generates consciousness. Since the mind has no other tool of apprehension, it cannot fail to impose the limitations of its own cognitive structure in its attempts to understand its own functions. The self that is the ground of consciousness cannot be known - as is well known, Kant’s view is that the noumenal nature of the mind is necessarily unknowable to us. His view is in stark contrast to experimental functionalists who seek to confirm or modify their accounts according to developments in biology, neuroscience, and psychology.
Trying to analyse discursive minds with discursive minds puts us in a curious pinch. We have a sort of metaphysical blind spot with regard to the ultimate reality of the ground of consciousness. The ultimate psychophysical links must necessarily remain unobservable to us because the two worlds - the intellectual and the physical - have fundamentally different characters. Our thoughts, from our perspective, do not occupy space. But physical objects do, so at best we will find the physical-intellectual correlates, but not the complete reduction hoped for by some physicalists, and functionalists. In this regard, Kant sounds remarkably like some contemporary mysterians about consciousness like Colin McGinn, Noam Chomsky, and Thomas Nagel.