Wednesday, July 13, 2016

Consciousness and the real world

The New York Times recently reprinted an essay by Galen Strawson, "Consciousness isn't a Mystery. It's Matter".

I don’t usually review articles, but this one is I think worth reading. Strawson’s argument reverses the commonplace conception of what we know and don’t know about reality. Since I’ve long held similar views, his paper made me feel pretty good.

Briefly, this is how I interpret his thesis: The Hard Problem is not Consciousness. It’s Physical Reality. Physics offers an incomplete view of reality. It tells us how reality works, but it does not and it cannot tell us what reality is. This point was a commonplace one 100 years ago, Strawson writes, but it has gotten lost in the recent discussion of consciousness. Stephen Hawking makes [this point] dramatically in his book “A Brief History of Time.” Physics, he says, is “just a set of rules and equations.” The question is what “breathes fire into the equations and makes a universe for them to describe?” What is the fundamental stuff of physical reality, the stuff that is structured in the way physics reveals? The answer, again, is that we don’t know — except insofar as this stuff takes the form of conscious experience.

In a post about Schrödinger’s Cat, I made the point that what physics offers us is a model of reality, of whatever-it-is that’s out there. Models are inherently limited. Whether built of equations or of plastic and metal, a model is not the prototype. It’s not even a replica of its prototype. (1) A model behaves in some limited respects like its prototype, which can be useful. A bridge design, that is, a conceptual model of a bridge, allows us to calculate the stresses well enough that the real bridge built according to that design will carry traffic without falling down. (2)

The model of the bridge can exist in several media: drawings, sets of equations and algorithms, physical objects made of wood or plastic or metal. None of them is the actual bridge, and none of them captures the total reality of the bridge. But, says Strawson, we can know the real bridge, insofar as [the bridge] takes the form of conscious experience. Indeed we can. We can look at it, we can hear the wind make the supporting cables hum, we can feel it shake as a truck passes over it, we can feel the texture of the railings as we hold on to them. That, implies Strawson, is the physical reality that our models can never capture. But our conscious experience is what we know directly, and all that we can know, of physical reality.

So the hard problem is the problem of matter (physical stuff in general). If physics made any claim that couldn’t be squared with the fact that our conscious experience is brain activity, then I believe that claim would be false. But physics doesn’t do any such thing. It’s not the physics picture of matter that’s the problem; it’s the ordinary everyday picture of matter. It’s ironic that the people who are most likely to doubt or deny the existence of consciousness (on the ground that everything is physical, and that consciousness can’t possibly be physical) are also those who are most insistent on the primacy of science, because it is precisely science that makes the key point shine most brightly: the point that there is a fundamental respect in which ultimate intrinsic nature of the stuff of the universe is unknown to us — except insofar as it is consciousness.

Strawson implies that reality is consciousness.  I’m not sure that I agree with that. But his stance has at least two advantages over the notion that Consciousness is the Hard Problem.

First, it reminds us that physics itself is motivated by a desire to make sense of our conscious experience. The fact that our models become ever more abstract, become “sets of rules and equations”, is a side effect of the experimental process that we believe yields objectively true insights. (3)

Secondly, it validates the empirical stance. We test accounts of reality, no matter how abstruse or abstract, against our own experience. “Truth” is the feeling we have that what’s been said corresponds to reality as we perceive it. This is as true about the most mystical theology as about the most concrete engineering problem. It’s as true about the silliest confabulations as about the most tested and proven claims.

“The truth is out there” undergirds all our sense of reality. But we know the truth only by sensing congruencies between different remembered experiences. Whatever is “out there” will forever be a mystery. That was Plato’s point in his image of the cave. His mistake was to believe that reasoning could access the reality outside the cave. He began the line of thought that ends with the blithe assumption that the “sets of rules and equations” describe reality not only more accurately but more completely than the accounts of our own experience.

There’s an irony here: The more we try to understand the nature of reality, the more we retreat from it. As Russel pointed out, in mathematics we know whether what we are saying is true, but we don’t know what it’s about; while in poetry we know what we are talking about, but we don’t know whether what we are saying is true. With all its quirks and imperfections, the conscious world is the only reality we know.

Footnote 1: There is a difference between a scale model of a steam locomotive that runs on steam, and a full size replica of the same locomotive. The model's boiler, for example, will have thicker than scale walls, else it cannot sustain the necessary steam pressure. The model will not accelerate and decelerate in scale proportion, because its power-to-mass ratio will be different.

Footnote 2: Nineteenth century theories of bridge behaviour were incomplete enough that many bridges fell down, and many people died. The real bridge does not behave exactly as modelled, thus giving graduate students in engineering lots of opportunity to observe them and refine the models.

Footnote 3: Quoting Bertrand Russell, Strawson writes:  “We know nothing about the intrinsic quality of physical events,” [Russell] wrote, “except when these are mental events that we directly experience.” In having conscious experience, he claims, we learn something about the intrinsic nature of physical stuff, for conscious experience is itself a form of physical stuff.

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