Tuesday, August 11, 2009

An Improved Supervenience Base?

Brian Weatherson (home page, blog) has authored an SEP article on David Lewis. In it he ably takes on the difficult task of summarizing in a few dozen pages the work of one of the most prominent and productive philosophers of the latter part of the twentieth century.

One section addressed something I had idly wondered about Lewis. As Weatherson discusses in his section 5, entitled “Humean Supervenience”, much of Lewis work involved reduction: whether the subject was the mind, language, laws of nature, or causation (modality was a rather spectacular exception), he presented arguments that all the truths about a world ultimately supervene on a set of (perfectly natural) properties and relations in that world. He then argued that these, in turn, are intrinsic properties of point-sized objects and spatiotemporal relations. (The “Humean” aspect of this is that he follows the spirit of Hume’s “dictum” that there are no necessary relations between distinct entities.)

What I had wondered was: did Lewis ever acknowledge that his picture of locally distributed point-sized objects in a space-time container was a classical view, inconsistent with modern physics?

Those who challenged this aspect of Lewis’ work over the years argued that his supervenience base is incapable of supporting some of the truths about the world, and so his attempts at reduction fail. However, most critics haven’t quibbled with the assumptions about physics, rather they argue that some additional higher-level properties and/or relations need to be added to explain the world. Even many materialist philosophers think additional brute metaphysical structure beyond the basic physical entities is required (this debate was the subject of this old post); some philosophers think necessary connections are needed to explain causation; dualists will see a need for fundamental mental properties and perhaps psycho-physical laws.

But, Weatherson notes that a second way to argue against Lewis’ project is indeed to point out that modern physics is inconsistent with Lewis’ notions. At a minimum, he says, quantum physics seems to need non-spatiotemporal relations to explain Bell’s theorem.

Weatherson explains that Lewis was indeed aware that his picture was inconsistent with quantum physics, but still thought it was extremely valuable to defend the thesis regardless of that fact. Weatherson explains the idea as follows: to the extent his picture of physics is wrong, it is because physics has more content in it (e.g. entanglement relations) rather than less. So, if Lewis can successfully defend reduction of various folk theories on his terms, it will remain a valuable accomplishment.

That makes sense, but I still wonder if explicitly reckoning with quantum physics and its interpretation couldn’t helpfully reframe these philosophical debates. There is more to the shift from classical physics to quantum physics than just adding some non-local connections. There is the quantum measurement event itself, which I see as an ineliminable new addition to the basic constituents of nature. I think that mind and causation might be the targets of successful reduction given an improved supervenience base which featured a network of measurement events in its basic ontology. (Also, one neat thing about taking this approach is that we could hold on to Hume’s dictum. He may not have known about QM, but I think the indeterminism involved in measurement events is consistent with his insight.)

12 comments:

Allen said...

So, let me try putting it to you this way.

Two options:

1. Conscious experience is uncaused.

2. Conscious experience is caused by something that is uncaused.

Why would you prefer option 2 to option 1?

You can say you prefer option 2 because option 2 provides an explanation for consciousness, but really it doesn't, right?

Option 2 still involves a brute "from nothing" creation, just not of conscious experience, but instead of an entire universe. An entire universe which, by the way, contains conscious experience. So really you have STILL created conscious experience from nothing. BUT, for some reason, having also created a lot of extra stuff to serve as intermediate building blocks for it somehow makes you feel better about things.

So what explains the complexity of our conscious experiences? The universe. What explains the complexity of the universe? Nothing, that's just the way it is.

So conscious experience is too complex to exist fundamentally and uncaused, but the universe is NOT too complex to exist fundamentally and uncaused? What??? Given that the universe CONTAINS conscious experience, this argument doesn't make sense.

Does it? Do you see what I'm getting at here?

So from your earlier post:

"And yet in the past I’ve argued that in the case of first-person experience (FPE), a normal approach to physical reduction will fail. A reduction of experience to wholly non-experiential parts will eliminate what we seek to explain.

[...]

The problem is you can’t seem to get something ontologically brand-new in the macroscopic realm from mereological combinations of classical physical objects."

And this is a problem with physicalism. But an equally serious problem is that you can't *meaningfully* explain consciousness in terms of something (the physical universe) which itself has no explanation. And this applies to your Russellian physicalism also.

It would be like trying to explain the output of a truly random process. There is no explanation...it's random. That's it.

The universe has no explanation, it just exists. Uncaused. That's it.

OR:

Conscious experience has no explanation, it just exists. Uncaused. That's it.

I think the two are ultimately equivalent, but that the latter has the advantage of greater simplicity.

Science can continue it's attempts to develop mathematical models that mirror what we have observed in the past with greater and greater accuracy, but no one should mistake this for being an attempt to *explain* these observations or to determine what really exists (in an ontological sense).

Thoughts said...

"At a minimum, he says, quantum physics seems to need non-spatiotemporal relations to explain Bell’s theorem."

Have you read Louis De Broglie's original paper on quantum theory? Near stationary electrons would have near infinite phase velocity yet still be within the scope of Special Relativity. If you follow de Broglie's reasoning the phase wave approach is still applicable even if the wave is a probability wave...

Steve said...

Thoughts: thanks very much for the comment and the link.

Steve said...

Hi Allen. A couple of times, after explaining the problems with physicalism, you’ve said you think the Russellian stance has the same problems. But let me try to say why I don’t think so (at least in my interpretation). Part of the issue has to do, I think, with the difference between causation and composition.

Two options:

1. Conscious experience is uncaused.

2. Conscious experience is caused by something that is uncaused.


I'm not sure why you think I'm taking option number 2, given that I agree with you that consciousness is not caused by unexplained non-conscious things. Conscious experience is indeed uncaused and fundamental. However, I do feel the need to qualify option 1 to state that our human-level experience is COMPOSED of smaller experiential units. It is untenable to me that our everyday human experience is the pure and simple unit of being given what we see in biology, neuroscience, etc.

The universe has no explanation, it just exists. Uncaused. That's it.

OR:

Conscious experience has no explanation, it just exists. Uncaused. That's it.


Again, I don’t feel my view fits easily into this dichotomy, given that I think the universe is composed of experiences. If in the second choice I can replace human conscious experience with generic experiential events (of which the human kind is one sort) then I'm happy with that.

And with regard to the worries about complexity: our universe is complex. There’s just no denying it. And our human level conscious experience is at a middle level of being – there is smaller stuff, and there are even bigger composite entities like galaxies. (Galaxies are not caused by stars, they are composed of them, but have a structural characteristics in their own right.)

But, if I recall a past dialogue we had, maybe I don’t have to worry about this complexity, since if everything exists in the multiverse, this is actually equivalent to having informational complexity of zero (or something like that :)).

Allen said...

>> However, I do feel the need to qualify option 1 to state that our human-level experience is COMPOSED of smaller experiential units.

What are the laws that govern possible combinations of smaller experiential units? Where do these laws come from? What causes these laws?


>> It is untenable to me that our everyday human experience is the pure and simple unit of being given what we see in biology, neuroscience, etc.

Biology? Neuroscience? What do these have to do with a reality composed of smaller experiential units???

So you say that your view is different from plain physicalism, but in this sentence it sounds to me like you've just taken plain physicalism and said "inside every subatomic particle/field quanta/string/whatever is a little bit of experience...but everything else is the same". In which case, my view is that I'm correct...the Russellian stance has the same problems as non-Russelian physicalism.

Do neurons exist *in* our experience, or do neurons *cause* our experience?


>> If in the second choice I can replace human conscious experience with generic experiential events (of which the human kind is one sort) then I'm happy with that.

Well, that's fine, but what explains the rules/laws of composition for experiential events? Or are you saying that all possible combinations of these "generic (?) experiential events" occur in some fashion?


>> (Galaxies are not caused by stars, they are composed of them, but have a structural characteristics in their own right.)

Galaxies are something that we have conscious experience of, like chairs. But I can dream of chairs, and I can dream of galaxies. I can be conscious of a chair or galaxy in my dreams as well as when I'm awake. They exist as part of the contents of our conscious experience, and we only know them through our conscious experience.


>> But, if I recall a past dialogue we had, maybe I don’t have to worry about this complexity, since if everything exists in the multiverse, this is actually equivalent to having informational complexity of zero (or something like that :)).

Yeah, I've changed my mind about all of that. So maybe all possible experiences exist. Maybe they don't. Before I thought it was reasonable to conclude that they did, as a consequence of the theory I had at the time. BUT, I've drastically changed my views over the last month.

So, in a nutshell, here's my reasoning on that change:

1) Physicalism has an explanatory gap between matter and consciousness.

2) Platonism, which initially seemed better, also has an explanatory gap, between ideals and consciousness.

3) Uncaused things (objects, events, whatever) cannot have meaning or be explained.

4) Even setting aside the explanatory gap, all causal explanations of consciousness ultimately lead to uncaused origins.

5) Things which follow entirely from uncaused beginnings are themselves ultimately uncaused.

6) Therefore, one way or another, directly or indirectly, consciousness is uncaused.

7) Given the choice between directly uncaused or indirectly uncaused, I'll take directly uncaused.

Our conscious experiences just are. Reality is tautological. It is what it is.

Jeff said...

In the end, some basic truths must be acknowledged. As Allen touched on, the fact is that reality has never been separated from your consciousness experience. All of the science, neurophysiology, logic, philosophy, religion, art, sensation, etc and everything that you have ever known or ever will know has never actually been separated from that experience. Not ever. The self cannot be separated from anything, and that makes all of reality a very personal thing.

But besides this profound isolation, consciousness does actually have some interesting properties. The "aboutness" or "intentionality" (as philosophers call it), of most mental activity is apparent. Whenever you think of anything, you always think "about" it - and by doing that, you automatically "objectify" everything, even if you think "about" yourself in the first person. To actually truly perceive yourself as a subject and not an object, is probably impossible.

Another interesting property that occurs to me is that we are actually only conscious "about" one thing at a time. Yes, there are many things going on subconsciously all over the mind, but as anyone can attest to, only one high-level "idea" at a time occupies the central arena of awareness or experience - the arena we call the "self" or the "mind's I". We can notice that other sounds are happening in background while we're talking, for example, but not without bringing the subconscious memory of them into into this special arena of awareness. We might think that a high-level "idea" is a complex thing composed of many other associated ideas or patterns of activity in the mind that give it meaning, but in order for us to experience associated ideas or become "aware" them, they have to enter this arena of experience and, at least temporarily, displace the previous idea. Of course from our perspective, it all happens very rapidly, with related ideas popping into and out of awareness, oscillating and mutating into new ideas, etc. The number and types of ideas are virtually endless (depending on your memory), but there is still only one arena where they are experienced. If there were two arenas, then you would actually be two separate people with the same memories - a deep identity problem directly related to why-am-I-me (which one of those arenas would "you" be, and why?). So the question becomes, is there a physical correlate to this conscious arena of experience? Does it correlate to somewhere specific in the brain? If so, then perhaps that brain structure may provide some great insights into consciousness. Of course (due to why-am-I-me), the arena could never be completely explained in physical terms, but it could still be helpful. A hypothetical "soul" could be anything from an irreducible point of perspective in some unknown space, to a complex immaterial "substance". But if there is a specific area in the brain correlated with "one-thought-at-a-time experience", then from a physicalist perspective, any interaction with a "soul" would occur there.

Thoughts said...

Allen: "Physicalism has an explanatory gap between matter and consciousness."

I know this is a popular idea but the truth is that materialism has a gap but physicalism does not have a gap.

As it says in the entry for "physicalism" in the Stanford Encyclopedia of Philosophy:

"Physicalism is sometimes known as materialism. Historically, materialists held that everything was matter -- where matter was conceived as "an inert, senseless substance, in which extension, figure, and motion do actually subsist" (Berkeley, Principles of Human Knowledge, par. 9). The reason for speaking of physicalism rather than materialism is to abstract away from this historical notion, which is usually thought of as too restrictive -- for example, forces such as gravity are physical but it is not clear that they are material in the traditional sense (Dijksterhuis 1961, Yolton 1983). It is also to emphasize a connection to physics and the physical sciences. Indeed, physicalism is unusual among metaphysical doctrines in being associated historically with a commitment both to the sciences and to a particular branch of science, namely physics."

Materialism has been a disaster for philosophy of mind (See Materialists should read this first). Physicalism is different, it is open ended and probably 99.9% of physical theory is undiscovered and unknown. There is no explanatory gap between physicalism and mind, just observations awaiting hypotheses.

If you are absolutely certain that materialism cannot explain mind then your responsibility as a scientist is to seek hypotheses that do embrace the mind. The huge flaw in materialism is that it fails to model dimensional time in a realistic fashion (it also fails to model the other aspect of time, "change", at all). So, if you want to understand the nature of conscious experience the starting point should be an investigation of time. William James, Bergson, Whitehead and other philosophers took this approach at the start of the previous century but were ignored as Behaviourism and Marxist Materialism swept over everything.

Steve said...

Allen:
What are the laws that govern possible combinations of smaller experiential units?

This is indeed the big unsolved question for the panexerientialist view. But I think it is a solvable problem, not a metaphysical conundrum (akin to an unsolved problem like the origin of life).

Do neurons exist *in* our experience, or do neurons *cause* our experience?

That's a good question. I think my experience is an emergent phenomenon, which arises from the spontaneous coordination of neurons and perhaps other constituents. Is this causation in the traditional sense? I'm not sure. It doen't involve precedence in time, like one billiard ball striking another.

Our conscious experiences just are. Reality is tautological. It is what it is.

I don't know. If my conscious experience can so easily be altered by drugs or a sharp blow to the head, it seems to be a part of a larger complicated system of which it is one constituent part. I can buy that conscious experience (per se) is a fundamental aspect of being which cant' be reduced to non-experiential parts; but my particular consciousness seems to be nothing special.

Steve said...

Hi Jeff.

The "aboutness" or "intentionality" (as philosophers call it), of most mental activity is apparent. Whenever you think of anything, you always think "about" it -

I agree with that; intentionality goes hand-in-hand with experience.

Regarding your discussion of the "arena", that makes sense -- and some of philosphers and psychologists appear to be pursuing that kind of idea in their search for a neural correlate of consciousness (e.g.Bernard Baar's 'global workspace theory'). I've wondered whether this particular aspect of our consciousness is the later product of the evolutionary development of the human brain/mind, and not necessarily as fundamental to conscious experience itself (perhaps a simple organism would have less need of this higher-level sorting arena).

Steve said...

Physicalism is different, it is open ended and probably 99.9% of physical theory is undiscovered and unknown.
I see what you're saying here ,thoughts. I agree that we should be able to expand/alter physics to incorporate mind. But as a practial matter, almost everyone still thinks of "physics" as particles of stuff moving in a classical spacetime container despite the fact that the last century of physics has made this picture untenable.

Doru said...

Hi Steve
The “hard problem of consciousness” has captivated my interest recently, so I guess that’s what had led me to your blog. I am yet to absorb some of your materials, so I can contribute with more objective comments here

Steve said...

Hi Doru. Thanks for checking out things here.