The word “thought” is used in the following essay. That’s even though it isn’t a discussion of the semantic content of particular thoughts. It’s not about what thoughts are about either. (All that would bring up all sorts of other issues such as externalism, “the extended mind”, reference, sense, “you are not your brain”, etc.) Instead, this is a discussion of any occurrent thought. That is, it’s simply about the mental process of thinking a thought and how that thought (or thinking process) is embodied (if it is embodied) in — or identical to (if it is identical to) — a brain state.
To repeat. All this means that we can discuss an occurrent thought without being committed to any particular semantic (rather than purely philosophical) theory or position.
That said, some of the claims in the following may seem a little extreme. Specifically the central claim about thoughts being located in the brain.
The eliminative materialist Paul Churchland — who’ll be featured in this piece — believes that the Identity Theory and in his own eliminative materialism may well come across as extreme. But that doesn’t matter much to him.
For example, Churchland ties his overall eliminativism to his revolutionary stance on the use of everyday words in science. He writes:
“The ‘abuse’ of accepted modes of speech is often an essential feature of real scientific progress!”
He then applies that to the case of mental states and their location by continuing:
“Perhaps we shall just have to get used to the idea that mental states have anatomical locations [].”
Churchland also frequently relishes citing the fact that many new claims in science have been deemed to be extreme or perverse only in time to be accepted by most people. (Of course that’s not also to say that all extreme or perverse claims will in time be accepted by most people.)
Location, Spatiality and Brain States
When you move across a room, your occurrent thought about, say, the price of bread (as it were) follows you. That is, if you begin thinking about the price of bread at one end of a room and move to the other end, then you’ll still be thinking the same thought (or set of thoughts) in another spatial location. And that’s because your brain has moved along with (as it were) you. (See “You are not your brain”.) Thus that thought must occur within the head.
In the past, thoughts were placed in the heart (see here) and, in later periods, just behind the eyes.
In any case, the fact that thoughts seem to be “inside” the head (or skull) must surely mean that they have a spatial nature. For something to be located in something spatial (a head or a brain), must hint that this something itself has a location and is therefore spatial.
Yet many philosophers and laypeople don’t believe that thoughts and other mental states have any spatial location whatsoever. (See ‘Consciousness and Space’ by Colin McGinn.) So why is that?
Much of what follows highlights the problems which come from simply assuming that conscious states are not brain states. And, if that’s assumed, then all sorts of things will follow (as we shall see).
That said, this piece is going to deal specifically with the spatial location of mental states.
So here’s the British-American philosopher Peter Carruthers (1952-) offering an argument (though not one he accepts) against the Identity Theory. He writes:
(1) All brain-states must occupy some particular position in space.
(2) It is nonsense (meaningless) to attribute any particular spatial position to a state of consciousness.
(C) So (by Leibniz’s Law) conscious states cannot be identical with brain-states.
The blatantly obvious problem with the argument above is that it simply and clearly assumes the fundamental distinction between brain states and conscious states from the very beginning — or at least from the second premise. So if the Identity Theorist takes his position seriously, then he’ll argue that conscious state C is a brain state B. Thus C — if only by this definition - can indeed have “some particular position in space”.
If, on the other hand, the conscious state isn’t a brain state, then it — again by this definition — can’t occupy the same position as a brain state.
The Canadian philosopher Paul Churchland (1942-) too is explicit on the subject of spatial location. He writes:
“[I]f mental states are identical with brain states, then they must have the very same spatial location.”
In other words, if mental states are indeed brain states, then it logically follows that they must have a spatial location.
So, to be fair to other options, here’s Churchland putting the arguments of those philosophers and laypeople who’re against the idea that mental states have a location. He continues:
“But it is literally meaningless, runs the argument, to say that my feeling-of-pain is located in my ventral thalamus, or that my belief-that-the-sun-is-a-star is located in the temporal lobe of my cerebral hemisphere. Such claims are as meaningless as the claim that the number 5 is green, or that love weighs twenty grams.”
The basic point here is the if such mental states are brain states, then because brain states have a spatial location, then mental states too must have a spatial location. Thus it’s often simply assumed that a thought is not a brain state. And if that’s assumed, then it becomes very feasible — or even logically necessary — to believe that it doesn’t have a (physical) spatial location.
Yet, despite all the above, many laypeople locate pains in the parts of the body which have been damaged, not in either the brain or mind!
It must also be noted here that Paul Churchland himself freely admits that feelings of pain and other mental states won’t be neatly mapped to any specific areas of the brain — but that doesn’t matter one jot. (Churchland doesn’t believe that beliefs and other propositional attitudes will be mapped at all — and that’s simply because he doesn’t believe that they exist in the brain.) As long as it’s the case that such pains, mental states, etc. are entirely identical to parts of the brain — no matter how complex these mappings are — that is all that matters. Indeed this is the case even if the entire brain needs to be brought into the mapping, explanation or description of a particular mental state!
And then there’s also the very big problem of externalist, extended mind, embodiment, etc. positions on mental content and semantics— especially when it comes to beliefs. (Arguably, less so when it comes to pain.)
In any case, what exactly does it mean to claim that conscious states don’t have a particular position or location in physical space?
Can a Conscious State be Non-Spatial?
Think about what it would mean to argue that a particular conscious state is non-spatial or has no location.
Wouldn’t that mean it is in some way — or even literally — abstract?
Would that mean that such a conscious state is equivalent to a number, a set, an equation, a law of physics, a Platonic universal, etc? Surely no one believes that — not even a fierce critic of the Identity Theory.
So if conscious state C isn’t abstract — then what, exactly, is it? What are the options?
The main option will be some kind of dualism in which the thought is believed to be non-physical and also (as it were) imbedded within some kind of (non-physical) substance. (The words “imbedded within” seem like a spatial metaphor and even the phrase “part of” is usually seen to be in some way spatial in nature — though abstract objects can have parts.) What’s more, this non-physical something still has a close and intimate relation — in terms of endless interactions — with the brain and the body.
The First-Person (or Private) View on Conscious States
Perhaps the seemingly(?) non-spatial nature of conscious states is largely — or even entirely — down to our subjective (or first-person) take on them. That is, to the (as it were) “owners” of conscious states, they do indeed seem to be non-spatial. Yet does a mental state seeming-to-be-non-spatial mean that it is non-spatial? Perhaps there’s a fundamental reason (perhaps purely phenomenological in nature) as to why the owner (or haver) of mental state C takes it to be non-spatial.
All this all ties in with broader takes on the privacy of conscious states.
So why is fundamental privacy given so much credence in this philosophical debate?
Firstly, how do we move from that stress on privacy (in this case, the non-spatial nature of mental states) to anything outside the domain of the private? Then how do we move to anything specifically scientific — and indeed anything philosophical — from that which is deemed to be intrinsically private? In other words, what work is this privacy doing? Is it just a brute and/or fundamental fact — full stop?
The following argument is how Peter Carruthers (again) expresses the importance and relevance of privacy to this debate. He writes:
(1) Conscious states are private to the person who has them.
(2) Brain-states are not private: like any other physical state, they form part of the public realm.
(Conclusion) So (by Leibniz’s Law) conscious states are not in fact identical with brain-states.
Not many people doubt premise (1). What’s more, a behaviourist or eliminativist position isn’t being advanced in this essay either. However, this question remains:
What can we conclude given that conscious states are private?
More clearly:
Is the claim that conscious states are non-spatial itself largely (or even entirely) down to their being private?
This means that it follows that because “[c]onscious states are private to the person who has them”, then the notion of the non-spatiality of those states will also be private to the person who has them. Yet how can we draw out the actual non-spatiality of conscious states from the personal “reports” on them?
Again, from a private (or phenomenological) viewpoint, conscious states do seem to be non-spatial. Yet that private seeming doesn’t mean that mental states are non-spatial.
To repeat.
When a subject has a conscious state, it seems (to that subject) to be non-spatial. Yet why should we accept that conscious state C is non-spatial simply because its owner takes it to be that way? What relevance does that personal (or private) account of a mental state have on its actual metaphysical status?
To take an extreme analogy.
Subject S may believe that the cricket bat in the water is bent. Yet that doesn’t mean that the cricket bat in the water is bent — it is refracted. Similarly, subject S hallucinating a red goblin is “private to the person” who has that hallucination. Yet we wouldn’t conclude that the red goblin exists. So perhaps we can conclude that the seemingly non-spatial nature of mental states is purely a product of private states. Thus we shouldn’t also conclude that such mental states actually are non-spatial.
Now take another loosely analogical argument.
The reader’s experience (or observation) of a specific concrete building isn’t identical to that concrete building itself. And my own experience (or observation) of that concrete building isn’t identical to the reader’s experience (or observation) of that same concrete building. In these simple cases, then, few people would claim an absolute identity between an experience (or observation) of a concrete building (or an experience/observation of anything else) and the building itself. That is, the experiences (or observations) of that building are never confused (or conflated) with the building itself.
Yet aren’t many people doing something similar to that when it comes to their own mental states?
More specifically, conscious states seem to be non-spatial. Therefore many people believe that conscious states are non-spatial. Yet that would be like seeing the concrete building as actually being black and white when wearing sunglasses (or even if one is suffering from a retinal problem of vision). Sure, the cases aren’t identical because mental states are private; whereas the concrete building is far from being private. Yet that doesn’t mean that we can’t make mistakes about private conscious (or mental) states. Indeed there’s a large literature on this very subject which tells us that we often do (see here).
So are such people taking their own positions — or views — on their own mental states to be gospel?
That last claim doesn’t mean that people make mistakes about the very (as it were) having of a mental state or even their experience of its phenomenology. The mistakes come when people describe — or theorise about — their mental states. Mistakes also come about because of people’s assumptions about their own mental states. (The non-spatial nature of thought isn’t the only example of this.) So such descriptions, theories and assumptions may be highly mistaken or confused.
All that said, there’s no eliminativist or behaviourist denial of private conscious states here. What is being questioned is what we say or believe about our mental states. And, in this case at least, many people believe (if only when pressed and given a philosophical vocabulary) that all their conscious states are non-spatial.
Paul Churchland on Introspection and Neural States
Despite all the above, mental privacy can be — or at least it can become — scientifically kosher.
So let’s get back to Paul Churchland on the introspection of mental states.
Despite what some (or even many) philosophers and laypeople believe, Churchland does not deny that there is such a thing as introspection. (For that matter, Churchland doesn’t deny that people have thoughts, pains or mental states generally.) That said, his position on introspection — and on much else — is truly radical, if not revolutionary.
For example, take Churchland’s detail as to why even introspection deals with scientifically acceptable phenomena.
To begin with, Churchland states the following:
“For if mental states are indeed brain states, then it is really brain states we have been introspecting all along, though without fully appreciating what they are.”
So when we introspect we “may discriminate efficiently between a great variety of neural states”. However, we may not “being able to reveal on its own the detailed nature of the states being discriminated”.
The conclusion here is that although Churchland wants to eliminate propositional attitudes, he doesn’t actually want to eliminate mental states in toto. Quite simply, that’s because this would be impossible. Instead Churchland wants to re-envision what mental are and how we should theorise (or philosophise) about them.
**********************************
Note
(1) Initially I was both wary and embarrassed about discussing the subject above because it has literally generated hundreds — or much more! — papers and articles over the last four decades. (Most papers have been written within the limited domain of analytic philosophers and postgraduate students — but that’s still a huge amount of words.) So I deliberately didn’t do extensive research on this subject because there’s simply so much one could research! And I didn’t do what postgraduates usually do — study everything (academically trendy) that’s been written on subject X in the last two decades, go through all the multiple options, comment a little, then tweak one’s own take on the subject. All to display one’s “research skills” into the bargain — with the addition academese prose style plus an infinite number of footnotes, endnotes and references.
No comments:
Post a Comment