Against the necessary unity of consciousness

Consider this unity of consciousness thesis:

1. Necessarily, if x at time t has phenomenal state A and phenomenal state B at time t, then x at t has a phenomenal state that includes both A and B.

(Note that (1) seems incompatible with time travel. But that is perhaps fixed by specifying that we are talking about internal time in (1).)

Christians have special reasons to be dubious of (1).

Start with this quick thought. Around 30 AD, the Logos was suffering pain on the cross and comprehensively experiencing his infinite divinity. But the Logos did not have a phenomenal state that subsumed these two phenomenal states. For orthodox Chalcedonian theology has it that the Logos had two minds: a divine mind and a human mind. Only in the divine mind can one have a mental state that subsumes the comprehensive experience of divinity. But no state subsuming suffering can be found in the divine mind.

This argument is suggestive but not conclusive. For we might say that it is not correct to say that the Logos has the divine experience around 30 AD, because God is outside of time.

But as we learn from Aquinas, once we accept that one incarnation of the Logos is possible, we should also accept that two simultaneous ones are possible. There are no further conceptual difficulties in two than in one, and if omnipotence allows for one, it should allow for two. But if the Logos had two simultaneous incarnations, then the Logos would have, in addition to the divine mind, two temporal creaturely minds. And if one of these minds houses unmitigated joy and the other sorrow, then none of the three minds of the Logos would house a state that includes both the joy and the sorrow, and hence the Logos would not have such a subsumptive state.

Further, if (1) is true, surely so is:

2. Necessarily, if x timelessly has phenomenal state A and phenomenal state B, then x timelessly has a phenomenal state that includes both A and B.

And now imagine that the timeless Logos engages in an analogue of the incarnation but as a timeless conscious being. Then the timeless Logos would have a divine phenomenal state and a human one which would not be unified.

Here is another thought against (1). Suppose that in heaven, Peter enjoys the beatific vision of God while enjoying Paul’s singing. A subsumptive phenomenal state that includes both the beatific vision and Paul’s singing would then be greater than either one of the included states. But no phenomenal state that Peter has is greater than Peter’s beatific vision.

There is a metaphysical version of this argument. The beatific vision has God directly as its content, rather than merely having a representation of God as its content. A state that included the beatific vision and Paul’s singing would have to have as its content God himself plus a representation of Paul’s singing. But there is no way to have a whole of which God is a proper part (Aquinas considers this to be a part of divine simplicity; but we might also think it follows from Anselmian theology—there cannot be anything greater than God).

Of course, even if (1) is false in general, a non-modal version may be true restricted to ordinary human phenomenal states, and we still will need an explanation of that fact. And it may be that some of the arguments people make from (1) against various materialist theories of consciousness would apply against the restricted thesis.

The unity of consciousness

I am now simultaneously aware of the motion of my fingers and of the text on the screen. Call this co-awareness. Co-awareness is not the same thing as awareness by the same subject. For if I type with my eyes closed and then stop typing and open my eyes, the tactile and visual experiences still have the same subject, but there is no co-awareness. Perhaps co-awareness is awareness by the same subject at the same time. But experiments on split-brain patients suggest that it is possible to have one subject with two simultaneous awarenesses that are not co-awarenesses.

Consider this very simple theory of co-awareness: it is not possible to have co-awareness between two distinct awarenesses. The case I started this post with was poorly described. Strictly speaking I had a single awareness of the conjunctive state of affairs of my fingers moving and there being text on the screen. I did not have an awareness of my fingers moving, nor did I have an awareness of text on the screen, but only of the conjunction.

On this view, rather than my co-hosting a quale of moving fingers and a quale of black markings on a white background, I am hosting a conjunctive quale of moving-fingers-and-black-markings.

All this, however, seems implausible. It certainly doesn’t fit with how we talk: everyone would say that I was aware of my fingers moving.

Similarly, I note, if Alice were to tell me that Bob was lazy and stupid, I would be correct to report that Alice told me that Bob was lazy, even though Alice did not in fact express the proposition that Bob was lazy, but only the conjunctive proposition that he is lazy and stupid. It is good use of ordinary language to attribute the statement of a conjunct to someone who stated a conjunction containing that conjunct. The same is true of awareness: we can attribute the awareness of a conjunct to someone who is aware of a conjunction. Maybe the right way to talk about this is to distinguish non-derivative and derivative, or focal and non-focal, senses of assertion and awareness. Alice non-derivatively asserts that Bob was lazy and stupid, and derivatively that Bob was lazy. I am non-derivatively aware of the conjunctive state of affairs of motion of my fingers, the text on the screen and a variety of other things, and derivatively of each conjunct.

With this distinction, we can build on the simple theory of co-awareness:

1. It is not possible to have co-awareness between two distinct non-derivative awarenesses.

2. Co-awareness occurs between two derivative awarenesses A and B provided that there is a non-derivative awareness C such that I count as having A and B in virtue of C being an awareness of a conjunction that includes the object of A as well as the object of B as a conjunct.

In a way, this simply shifts the difficulty of figuring what makes it be the case that an awareness is an awareness of a conjunctive state to the difficulty of figuring out what makes a non-derivative awareness of a conjunction be an awareness of a conjunction. That is, indeed, a tough problem. But it is a problem that is just a special case of a general problem that we would need to solve even if we had solved our original co-awareness problem in some other way: the problem of the logical structure of the objects of perception. If I see a shape in the distance that looks like a dog or fox, what is it that makes me have an awareness of a disjunction between a dog or a fox? If I see something that looks like it’s not a dog, what is it that makes me have a negative awareness of a dog?

It may seem puzzling how there can be a logical structure to qualia. I don’t see why not. But then I am strongly inclined to a representationalism that holds that the differences in the qualitative properties between conscious states are determined by the differences between the states’ representative properties. And representative properties have a logical structure.

Synchronization and the unity of consciousness

The problem of the unity of consciousness for materialists is what makes activity in different areas of the physical mind come together into a single phenomenally unified state rather than multiple disconnected phenomenal states. If my auditory center active in the perception of a middle C and my visual center is active in the perception of red, what makes it be the case that there is a single entity that both hears a middle C and sees red?

We can imagine a solution to this problem in a computer. Let’s say that one part of the computer has and representation of red in one part (of the right sort for consciousness) and a representation of middle C in another part. We could unify the two by means of a periodic synchronizing clock signal sent to all the parts of the computer. And we could then say that what it is for the computer to perceive red and middle C at the same time is for an electrical signal originating in the same tick of the clock to reach a part that is representing red (in the way needed for consciousness) and to reach a part that is representing middle C.

On this view, there is no separate consciousness of red (say), because the conscious state is constituted not just by the representation of red (say) in the computer’s “visual system”, but by everything that is reached by the signals emanating from the clock tick. And that includes the representation of middle C in the “auditory system”.

The unification of consciousness, then, would be the product of the synchronization system, which of course could be more complex than just a clock signal.

This line of thought shows that in principle the problem of the unity of consciousness is soluble for materialists if the problem of consciousness is (which I doubt). This will, of course, only be a Pyrrhic victory if it turns out that no similar pervasive synchronization system is found in the brain. The neuroscience literature talks of synchronization in the brain. Whether that synchronization is sufficient for solving the unity problem may be an empirical question.

The above line of thought also strongly suggests that if materialism is true, then our internal phenomenal timeline is not the same as objective physical time, but rather is constructed out of the synchronization processes. It need not be the case for this that the representation of red and the representation of middle C happen at the same physical time. A part further from the clock will receive the synchronizing signal later than a part closer to the clock, and so the synchronization process may make two events that are not simultaneous in physical time be simultaneous in computer time. I suspect that a similar divide between mental time and physical time is true even if dualism is (as I think) true, but for other reasons.

Relativity, brains and the unity of consciousness

I was grading undergraduate metaphysics papers last night and came across a very interesting observation in a really smart student’s paper on Special Relativity and time (I have the student’s permission to share the observation): different parts of the brain have different reference frames, and so must experience time slightly differently.

Of course, the deviation in reference frames is very, very small. It comes from such facts as that

• the lower parts of the brain are closer to a massive object—the earth—which causes a slight amount of time dilation, and

• we are constantly wobbling our heads in a way that makes different parts of the brain move at different speeds relative to the earth.

Does such a small difference matter? As I understand their argument, my student thought it would make the A-theory less plausible. For it makes it questionable whether we can say that we really perceive the true objective now in the way that A-theorists would want to say we do. That’s an interesting thought.

I also think the line of thought might create a problem for someone who thinks that mental states supervene on physical states. For consider the unity of consciousness whereby we are aware of multiple things at once. If the consciousness of these different things is partly constituted by different chunks of the brain, then it seems that what precise stream of consciousness we have will depend on what reference frame we choose. For instance, I might hear a sound and feel a pinch at exactly the same moment in one reference frame, but in another reference frame the sound comes before the feeling, and in other the feeling comes before the sound. But that seems wrong: the precise stream of consciousness should not depend on the reference frame.

This shows that if the order of succession within the stream of consciousness does not depend on the reference frame (and it is plausible that it does not), then the precise stream of conciousness cannot supervene on physical states. This is clear if there is no privileged reference frame in the physical world. But even if there is a metaphysically privileged reference frame as A-theorists have to say, it seems reasonable to say that this frame is “metaphysical” rather than “physical”, and hence a dependence of consciousness on this frame is not a case of supervenience of mind on the physical.

Here is what I think we should say: If the A-theory is true, then the mind somehow catches on to the absolute now. If the B-theory is true, then the mind has its own subjective timeline, which is not the timeline of the brain or any part of it.

I think a really careful materialist might be able to affirm the latter option, by analogy to how in a modern digital computer, even though at the electronic hardware level there is analog time (perhaps itself an approximation to some frothy weird quantum time), synchronization of computation to clock ticks results in the possibility of abstracting a precisely defined discrete time that “pretends” that all combinatorial logic happens instantaneously. Roughly speaking, the assembly language programmer works with respect to the discrete time, while the FPGA programmer works primarily with respect to the discrete time but has to constantly bear in mind the constraints that come from the underlying analog time. However, the correspondence between the two levels of time is only vague. Similarly, I think that it is likely that the connection between the mind’s timeline and the physical timelines is going to suffer from vagueness (though perhaps only epistemic). How philosophically happy a materialist would be with such a view is unclear, and there is a serious empirical assumption here for the materialist, namely that the brain has a global synchronizing process similar to a microprocessor’s or FPGA’s synchronizing clock. I doubt that there is, but I know very little of neuroscience.

My experience of temporality

This morning I find myself feeling the force of presentism. I am finding it hard to see my four-dimensional worm theory as adequately explaining why my experience only includes what I am experiencing now, instead of the whole richness of my four-dimensional life. I am also finding it difficult to satisfactorily explain the sequentiality of my experiences: that I will have different experiences from those that I have now, some of which I dread and some of which I anticipate eagerly.

When I try to write down the thoughts that make me feel the force of presentism, the force of the thoughts is largely drained. After all, to be fair, when I wrote that I have am having trouble “explaining why my experience only includes what I am experiencing now”, shouldn’t I have written: “explaining why my present experience only includes what I am experiencing now”, a triviality? And that mysterious sequentiality, is that anything beyond the fact that some of my experiences are in the future of my present experience?

The first part of the mystery is due to the chopped up nature of my consciousness on a four-dimensional view. Instead of seeing my life as a whole, as God sees it, I see it in very short (but probably not instantaneous) pieces. It is puzzling how my consciousness can be so chopped up, and yet be all mine. But we have good reason to think that this phenomenon occurs outside of temporality. Split brain patients seem to have such chopped up consciousnesses. And if consciousness is an operation of the mind’s, then on orthodox Christology, the incarnate Christ, while one person, had (and still has) two consciousnesses.

Unfortunately, both the split brains and the Incarnation are mysterious phenomena, so they don’t do much to take away the feeling of mystery about the temporal chopping up of the consciousness of my four-dimensional life. But they do make me feel that there is no good argument for presentism here.

The second part of the mystery is due to the sequentiality of the experiences. As the split brain and Incarnation cases show, the sequentiality of experiences in different spheres of consciousness is not universal. The split brain patient has two non-sequential, simultaneous spheres of consciousness. Christ has his temporal sphere (or spheres, if we take the four-dimensional view) of consciousness and his divine atemporal sphere of consciousness. But seeing the contingency of the sequentiality does not remove the mystery in the sequentiality.

It makes me feel a little better when I recall that the presentist story about the sequentiality has its own problems. If my future experiences aren’t real—on presentism they are nothing but stuff in the scope of a modal “will” operator that doesn’t satisfy the T axiom—then what am I anticipating or dreading? It seems I am just here in the present, and when I think about this, it feels just as mysterious as on four-dimensionalism what makes the future impend. Of course, the presentist can give a reductive or non-reductive account of the asymmetry between past and future, but so can the four-dimensionalist.

So what remains of this morning’s presentist feelings? Mostly this worry: Time is mysterious and our theories of time—whether eternalist or presentist—do not do justice to its mysteriousness. This is like the thought that qualia are mysterious, but when we give particular theories of them—whether materialist or dualist—it feels like something is left out.

But what if I forget about standard four-dimensionalism and presentism, and just try to see what theory of time fits with my experiences? I then find myself pulled towards a view of time I had when I was around ten years old. Reality is four-dimensional, but we travel through it. Future sufferings I dread are there, ahead of me. But I am not just a temporal part among many: there is no future self suffering future pains and enjoying future pleasures. The past and future have physical reality but it’s all zombies. As for me, I am wholly here and now. And you are wholly here and now. We travel together through the four-dimensional reality.

But these future pains and pleasures, how can they be if they are not had by me or anyone else? They are like the persisting smile of the Cheshire cat. (I wasn’t worried about this when I was ten, because I was mainly imagining myself as traveling through events, and not philosophically thinking about my changing mental states. It wasn’t a theory, but a way of thinking.) Put that way, maybe it’s not so crazy. After all, the standard Catholic view of the Eucharist is that the accidents of bread and wine exist without anything having them. So perhaps my future and past pains and pleasures exist without anyone having them—but one day I will have them.

Even this strange theory, though, does not do justice to sequentiality. What makes it be the case that I am traveling towards the future rather than towards the past?

And what about Relativity Theory? Why don’t we get out of sync with one another if we travel fast enough relative to one another? Perhaps the twin who travels at near light speed comes back to earth and meets only zombies, not real selves? That seems absurd. Maybe though the internal flow of time doesn’t work like that.

I do not think this is an attractive theory. It is the theory that best fits most of my experience of temporality, and that is a real consideration in favor of it. But it doesn’t solve the puzzle of sequentiality. I think I will stick with four-dimensionalism. For now. (!)

The unity of consciousness

Here’s a familiar kind of argument:

1. A spatial arrangement of ingredients of a mental life would not yield a unity of consciousness.

2. We have a unity of consciousness.

3. Our mental life is not constituted by a spatial arrangement of ingredients.

4. So, our minds are not spatially extended entities (and in particular they are not brains).

(The last step requires some additional premises about extension and mereology.)

But our unity of consciousness also includes ingredients that take time. We are aware of motion, and motion takes time. We consciously think temporally extended thoughts. If we take the argument (1)-(4) seriously, it looks like we should similarly conclude that our souls are not temporally extended entities.

This might be a reductio ad absurdum of the line of argument (1)-(4). For it seems that even the dualist will recognize the essentially temporally extended nature of many of our conscious states.

Or maybe it’s an argument for a Kantian view on which we have a noumenal self that is beyond space and time as the physicists conceive of them.

Special Relativity and physicalism

There is, I think, an underexplored argument against physicalism on the basis of Special Relativity and the unity of apperception.

The unity of apperception seems to imply that there is always a non-relative fact of the matter whether two perceptions are co-perceived: whether I am feeling cold at the same time as I am seeing a red cube, say. (Einstein’s own definition of simultaneity presupposes this: he defines the simultaneity of two distant events in terms of the co-perception of light beams from them.) When two perceptions are co-perceived, they are simultaneous. So there must be a non-relative simultaneity in the mind. But it is very unlikely that all co-perceived perceptions are grounded in exactly the same place in the brain. And simultaneity between physical events happening at different locations is always relative. So perceptions aren’t physical events.

I don’t think this is a very strong argument, though. It’s open to the physicalist to say that perceptual time is different from physical time, and perceptual simultaneity need not correspond to physical simultaneity. The best version of physicalism is functionalism. Now imagine embedding a causally isomorphic copy of Napoleon in a universe with four spatial and one temporal dimension, but in such a way that all of the four-dimensional life of Napoleon is realized within the four spatial dimensions, at a single temporal instant. The three spatial dimensions of Napoleon would be realized within three spatial dimensions, and the temporal dimension of Napoleon would be realized within the fourth spatial dimension. All the diachronic causation in the life of our world’s Napoleon becomes simultaneous causation in the new world. All of the life of the Napoleon-copy is then lived at a single instant of physical time, but it has all of the causal richness that Napoleon’s life had, and it is causally isomorphic to Napoleon. It is plausible, then, that the functionalist will say that Napoleon-copy has the same mental life as Napoleon. But Napoleon-copy’s mental life is all at once physically. So the functionalist can say that mental time is not the same as physical time—without budging from physicalism.

Now, I think some people will find this kind of a separation between physical time and mental time to be unacceptable. If so, then they shouldn’t be physicalists. I myself am not a physicalist, but I find the separation between physical and mental time quite plausible. After all, don’t we say that sometimes time runs faster than at other times?

Of minds, livers and the Incarnation

There is nothing absurd about that liver remaining a proper part of me while gaining a conscious mind. (Certainly this is true if materialism is true—cf. this post.) Then I would have two conscious minds as proper parts of me—the liver's mind and the one with which I now think. Plausibly, however, I would not be aware of what the liver is thinking. I can kind of imagine my liver being a homunculus of whose thoughts I am quite unaware. But, it seems, the liver's mind would be a part of me, and hence would be a mind of mine. And, surely, I should be conscious of what a mind of mine thinks.

So we have problem: if my liver gained a mind, it seems I would both be and not be conscious of what the liver was thinking. Now there is a way of embracing this paradox. I might distinguish as follows. In the hypothetical situation, I would have two minds, A and B. I would be aware of what both are thinking. But I would not be aware with A of what I am thinking with B, and I would not be aware with B of what I am thinking with A.

What is kind of fun is that the above considerations yield an argument for the disjunction of two controversial views, both of which I hold. Suppose you think it is absurd that I should gain a second mind and be unaware with this mind of what that mind is thinking. Then, I think, you need to stop my thought experiment from going through. I think your best bet for stopping my thought experiment from going through is to deny that my liver and my mind are parts of me. Maybe the best way to do this is to insist that I do not have proper parts. (Of course I also have a liver. But it does not follow that livers exist, just as it does not follow from my having had a fright that a fright existed.) If so, then the rejection of where my thought experiment leads to gives a plausible argument for the controversial thesis that I don't have proper parts.

But suppose one embraces the conclusion. Then, one accepts something else controversial that I hold, namely that it is possible for one person to have two minds, and to be unaware with one of what he is thinking with the other. The case I am interested in is that of Christ. He has a human mind and a divine mind. And with his human mind he, probably, cannot be aware of everything that he is divinely thinking. Of course, this may force a denial of the transcendental unity of apperception.