Molecular Storms and the Subtleties of Matter

First, links to other New Savanna posts bearing on the relationship of mind to matter:

• Galen Strawson on consciousness: the problem we face is simple, we underestimate the subtleties of matter

• Has Dennett Undercut His Own Position on Words as Memes? – In which Dennett discovers that metabolism is real

Peter Godfrey-Smith has posted a work in progress, Mind, Matter, and Metabolism (PDF), that bears directly on the issues in play in those two posts. Strawson argues that consciousness presents a problem to materialism only if we have much too simple a view of matter. Our understanding of "brute" matter has changed a great deal since the days of Descartes and Newton. Dennett doesn't express himself in those terms, but his recent reservations about computation are similar in effect. Here PGS speaks to computation (p. 2)

...with the rise of computers and AI. This work seemed to show that some aspects of cognition are mechanizable in principle, and in a non-living system. There's no question of life being present in a classical AI system, or a familiar sort of robot, and given that there seems a real possibility that such a system might capture of all of mentality, there can't apparently be too close a link between life and mind. Computation, rather than life, became the crucial bridging concept between mental and physical.

That's what Dennett thought. But he's now, sorta, realized that we've got to have life in there. PGS on "matter at the scale of metabolism" (p. 4):

Metabolic processes in actual cells occur at a particular spatial scale, the scale measured in nanometers – millionths of a millimeter. They also take place in a particular context, surrounded by water. In that context and at that scale, matter behaves differently from how it behaves elsewhere. In a phrase due to Hoffman, what we find is a molecular storm. There is unending spontaneous motion, which does not need to be powered by anything external. Larger molecules rearrange themselves spontaneously and vibrate, and everything is bombarded by water molecules, with the larger molecules being hit by a water molecule trillions of times per second. Electical charge also plays a ubiquitous role, through ions dissolved in the water and charged regions of larger molecules. The parts of a cell that do things in the usual sense – making proteins, for example – are subject to forces that are much stronger than the forces they can exert. The way things get done is by biasing tendencies in the storm, nudging random walks in useful directions, thereby getting a consistent upshot out of vast numbers of mostly meaningless changes. Moore, though not Hoffman, thinks we should conclude from all this that "Macromolecular Devices Are Not Machines." Moore thinks that a machine is a quite definite sort of thing, where low-level interactions are predictable and parts are tightly coupled. A storm-like collection of random walks influenced by friction, charge, and thermal effects, in contrast, is non-mechanistic.

On the origins of life (p. 5):

There probably never were any simple metabolisms – simple in the way that older models of the origins of life are simple. The transition that occurred went not from simple to complex, but from disorderly to orderly. Disorderly complex chemical systems gave rise to more orderly complex ones.

Later on that page:

The physical features of metabolism discussed above may be very far from accidental. Hoffman argues that the scale and chemical context seen in actual present-day metabolisms is the only place where we will find devices that run themselves: "The nanoscale is the only scale at which machines can work completely autonomously." At this level there is spontaneous motion, but there is enough structure and the relations between forces are such that a lot can happen, by biasing tendencies in random walks. It is at least very difficult, then, for life to arise outside this scale and context. Life could not have arisen in a dry-land macroscopic realm, on the scale of familiar machines. Perhaps once life exists in a "chemically easy" form, artifactual systems can be made that have different relations to energy and self-maintenance.

That last sentence speaks to the arguments Dennett seems to be making.

And then still later (pp. 7-8):

Starting with some obvious facts: all the systems we encounter that are clear and uncontested cases of systems with minds are also living systems. The same is true of nearly all the usual contested candidates – here I'm thinking of simple animals and very sophisticated AI systems. A converse principle is also true: all known (metabolically) living systems engage in some cognitive or proto-cognitive processes. I'll say more about the "proto-cognitive" in a moment, but we can think of it initially as involving sensing and responding to events, perhaps in minimal ways, and doing so in a way that helps keep the system alive.

And then (8-9):

First, a lot of the "control" processes seen in bacteria work through the genome, by the regulation of gene expression. The output of these systems is chemical, rather than "behavioral" in the usual sense. Genetic systems in all cells work via processes with a quite strongly computational character, with cascades of interactions that can be described in terms of ands, ors and nots. This looks like an immediate help to my case in this paper, but that is not really so straightforward. A person might say that computation is the crucial concept here, and computation is seen both inside and outside living systems. Computation is important for genes and important for thinking, but those are separate matters and computation also does not have any essential connection to life. That would be a reasonable point, and I think it shows that describing the biological role of computation, in an ordinary sense of that term, is not enough. But what we see prefigured in basic kinds of (metabolic) life is something more specific. It is the use of sensing and responding, often coordinated with boolean or boole-approximating operations, to maintain the integrity of a system and its activity, seeking and maintaining some states while avoiding others. A complicated collection of ands and if-thens with no metabolic point to them would not be the same sort of thing. When the genome is used to control the synthesis of metabolically important chemicals by means of feedback, or by tracking conditions in the external environment, that is proto-cognitive in the sense I have in mind.

That penultimate sentence – "A complicated collection…sort of thing"–would seem to strike at the heart of Dennett's realization, that he was from reading Terrence Deacon.

We're only a third of the way into the paper, and the rest is quite interesting, but you should be able to see where this is going so I'll leave off at this point.