By Stuart Kauffman
My purpose in the next several posts is to begin to explore major issues in the Philosophy of Mind. My hope is that it may be possible to bring to bear material from past posts to help resolve deep issues that have been with us at least since Descartes, in 1650. To do so, we need a brief outline of these issues.
Descartes famously postulated two kinds of "substance" in the universe, res extensa and res cogitans. Res extensa is, roughly the physical world. Res cogitans is, roughly, mind and consciousness. This view of two kinds of substances is called "dualism".
It was clear to Descartes that his dualism raised the deep issue of how mind/consciousness acts on the physical matter of the body, including the issue of how the mind can have a morally responsible free will. His own proposal was that the mind acted on the body via the pineal gland, a single gland in the brain.
With respect to res extensa, Descartes was an early mechanist: the world, and the bodies of animals and humans were conceived of as clock like machines, gears, escapements and so forth.
This early view was profoundly enriched by Newton's three laws of motion, universal gravitation, and the invention by Newton and Leibnitz of the calculus.
Recall that Aristotle had considered four causes, formal, material, final and efficient: the formal cause of a house is the blueprint, the material cause of the house are the bricks and mortar, the final cause of the house is your decision to build it, and the efficient cause is the actual process of building the house. As I have mentioned, Aristotle also offered a model for explanation in science: deduction: All men are mortal, Socrates is a man, therefore Socrates is mortal. As Robert Rosen pointed out in 'Life Itself', with Newton's laws in differential equation form, initial and boundary conditions, one has, say for a table of billiard balls, the initial positions and momenta of all the balls, the boundary conditions of the billiard table, then the physicist integrates the differential equations to get the trajectories the balls will follow. But as Rosen points out, integration is exactly Deduction. So Newton mathematized Aristotle's efficient case as integration of the differential equations for a system, and that became the "new" mechanical world view", for example Celestial Mechanics.
Note two things about Newton's triumph. First, from the perspective of an Alfred North Whitehead, or myself, who are both interested in exploring ontologically REAL Possibles giving rise to Ontologically real Actuals that give rise to Ontologically real Possibles, Newton's and Einstein's worlds are only Actuals. Thus, for Newton, what IS the Actual state of the billiard ball system in terms of positions and momenta, causally determines the next Actual state of the system, as revealed by integration of his equations of motion. Second, for Newton all events have sufficient Actual causes. There is no uncaused event. The forward and past (due to time reversibility of Newton's laws) trajectories of the billiard balls is entirely determined by the present state of the billiard balls's positions and momenta, and a sequence of Actuals that beget the next or preceding Actual.
With this in mind, let's return to a Cartesian dualism: We have a res extensa, described by Newton's deterministic equations. Now pass to a deterministic set of equations describing the dynamical neural behavior of the brain. Then we confront the profound problem: How does mind/consciousness - as we exprience it with our sense of free will - cause matter, res extensa to change? The standard philosophy of mind arguments are straightforward: 1) The brain, as a physical system is causally sufficient to generate the next Actual state of the brain, so there is nothing for mind to do. 2) Besides, there is no causal means by which Mind/Consciousness can act on matter.
We're stuck! One response was Idealism: this was Bishop Berkeley's theory that all is Res Cogitans, and what seem to be Res Extensa are so because they are held in the mind of God. There are a variety of Idealist positions spawned by Berkeley.
The modern view is called the "mind-brain" identity theory. It holds that causal events in the brain, say circuits of neurons firing creating a nonlinear dynamical system among about 10 to the 11th power neurons, constitute the causal behavior of the (classical) neurons, much like Newton, where Actuals give rise to the next Actuals in a state space of the firing activities of all 10 to the 11th power neurons at each moment, hence a flow along trajectories in this state space. But, since the mind and brain are identical, this very dynamical activity is mind and consciousness.
The mind-brain identity view is dominant today, and I agree with it, although not as formulated above.
A subspecies of this mind-brain identity theory is called "connectionism". Here is the idea. A neuron firing or not can be thought of as the truth or falseness of a proposition, say, "An edge at angle X is here in the visual field". Then the firing of all the neurons is like a computer calculating, a Turing machine, and vastly many computable functions can be carried out by the brain, calculating the true or falseness of vastly many propositions.
The neurological correlate of this is easily seen by receptor fields. Hubel and Wiesel showed in the 1950s that a given neural ganglion at the back of your eye could be stimulated to fire by points of light directed at small spots on your retina, but inhibited from firing by directing the light at a small circle on your retina surrounding the central excitatory spot. This is an on center off surround receptor field. Later they showed that there are receptor fields that respond to short lines of light with specific spatial orientations, and these are called edge detectors, for it was soon realized that a set of these receptor fields firing together could detect a straight edge spanning a number of edge receptor fields oriented in the same direction.
This triumph led to the "grandmother" cell theory, in which a specific neuron would fire if and only if you looked at your grandmother. This theory has fallen into disfavor, as such cells have not been found. More, this Connectionist vision of the brain typically is associated with the claim that the mind is algorithmic, a computational machine like a classical computer. In a later blog I will suggest that this view is deeply wrong, the mind is not algorithmic. But that is for later...
So what are the philosophic problems with the mind-brain identity theory?
"Well", a philosopher of mind commonly says, "let's take the "meat-brain" part of the mind-brain identity. Once again, it seems as if the Actual state of the brain is causally sufficient for the next Actual state of the brain, so again, there is nothing for mind to do." (You may wonder why the philosopher gets to ask this question if mind and brain are identical, but an actual survey of a modest number of good philosophers shows that they do ask this question.)
Worse, there seems no way for mind to act on the brain - just as in dualism.
One response is to say the conscious mind is a mere "epiphenomenon", of no power on its own to cause anything in the world of matter. Here, consciousness is either an illusion, or in any case, ineffective in the real world. This may be the position of Tom Clark and Ursula, my co-blogger, in her recent post when she says of Ursula, "she did this and that", meaning her brain did it, not Ursula. (I may have misunderstood a very good friend, who will surely tell me if I've misunderstood.)
So what about morally responsible free will? Here is the standard dilemma. The mind-brain is a deterministic dynamical system, a la Newton, but different "neural" equations. So you were determined by that dynamics to kill the old man in the wheel chair. Not your fault. You didn't do it. No responsible free will.
Alternatively, we have a little or a lot of quantum chance, in the simplest case, like the random decay of a radioactive nucleus. So you are sauntering down the street, and by random chance, kill the same old man in the wheel chair. Not your fault, just a random event.
Again we are stuck. We can have no responsible free will.
I will offer an argument later about a coherent, decohereing-recohering mind-brain system that has consequences for the classical world via decoherence, but decoherence that is acausal, so mind can have consequences for matter without acting causally on matter. I think this is actually very hopeful. It answers cleanly one of the outstanding problems in the philosophy of mind - IF the mind-brain system is quantum coherent, decohering and recohering, which none of us knows as yet.
A responsible free will is harder.
But there are further problems:
Why did consciouisness evolve anyway? Suppose an algorithmic robot with sensors could calculate exactly what will happen in its world. Why bother to be "aware" of its world, just buzz around and plug yourself into power sockets and pop oil into your joints.
What use, if mind is a machine, such as a connectionist machine, is there in being conscious, having awareness, or "qualia"?
Now you might think that an answer is that the robot cannot compute its world exactly due to measurement error, or what is called "deterministic chaos", the famous butterfly effect where a butterfly in Rio can change the weather in Chicago because tiny changes in initial conditions lead to widely varying trajectories in state space.
But this answer won't do. The unconscious, but able computerized robot could sense the difference between its predictions about the world and the world, reset the initial conditions and recompute. Why be conscious? There seems no answer.
This blog is at the philosophy of mind 101 level, of course, but I hope it set in place the context of the problems we face. In my next blogs I hope to take up these issues.
Post Script: In a recent blog, 'Can a Changing Adjacent Possible Acausally Change History? The Open Universe, IV', I discussed 'Vast chemical reaction graphs' and the flow of a small amount of matter on such graphs. I claimed equilibrium would never be reached in the lifetime of the universe, that fluctuations would not damp out but be history dependent, due to those very fluctuations that do not damp out, and that, if we interpret Quantum Mechanics in terms of an ontologically 'real possible', the entire process is acausal. A new study, just published in the Proceedings of the National Academy of Science, USA, of the famous Murchison meteorite that fell in Australia about 40 years ago, used high resolution mass spectrometry and NMR, able to detect mass differences of 1 electron. The study detected 14,000 organic compounds from which, the authors say, millions of organic compounds can be made. The data suggest the meteorite may be older than the sun and carry compounds from early in the formation of the solar system. My addition is that space chemistry may indeed be a flow on a hypo-polulated "vast" reaction graph as we have discussed.
With respect to the philosophy of mind for later blogs, this flow, if interpreted as I have done above, is acausal, lawless but non-random in its historical contingency, and offers a potential way out of the bind about free will as either deterministic, hence not free, or merely quantum random like the decay of a single radioactive nucleus, hence just random, so not morally responsible as we just happen to kill the old man in the wheel chair.
'Scientists say that a meteorite that crashed into Earth 40 years ago contains millions of different carbon-containing, or organic, molecules.'
More information: High molecular diversity of extraterrestrial organic matter in Murchison meteorite revealed 40 years after its fall, Philippe Schmitt-Kopplin et al., PNAS February 16, 2010 vol. 107 no. 7 2763-2768, doi: 10.1073/pnas.0912157107