H. Allen Orr on Nagel

H. Allen Orr is a biologist and a frequent player at the New York Review of Books.  The latter makes for essential reading both because and in spite of the fact that it is dedicated to defending a leftist orthodoxy.  Orr has been called on before, if my memory is correct, to debunk evolutionary psychology, with which the leftist orthodoxy is uncomfortable. 

Orr takes on Thomas Nagel’s book which I have been commenting on here.  It is an odd bit of debunking as it certainly attacks Nagel on some key points but, I think, sort of agrees with his larger point. 

Orr puts Nagel’s thesis in these terms:

Nagel insists that the mind-body problem “is not just a local problem” but “invades our understanding of the entire cosmos and its history.” If what he calls “materialist naturalism” or just “materialism” can’t explain consciousness, then it can’t fully account for life since consciousness is a feature of life. And if it can’t explain life, then it can’t fully account for the chemical and physical universe since life is a feature of that universe. Subjective experience is not, to Nagel, some detail that materialist science can hand-wave away. It’s a deal breaker. Nagel believes that any future science that grapples seriously with the mind-body problem will be one that is radically reconceived.

That is the point that is essential in Nagel’s book and I think that Orr comes very close to conceding it. 

Nagel concedes that many philosophers do not share his skepticism about the plausibility of reducing mind to matter. And I can assure readers that most scientists don’t. I, however, share Nagel’s sense of mystery here. Brains and neurons obviously have everything to do with consciousness but how such mere objects can give rise to the eerily different phenomenon of subjective experience seems utterly incomprehensible.

Yes.  Is it possible that some really big leap in science is required before consciousness can be accounted for, as Nagel insists? 

Science has, since the seventeenth century, proved remarkably adept at incorporating initially alien ideas (like electromagnetic fields) into its thinking. Yet most people, apparently including Nagel, find the resulting science sufficiently materialist.  The unusual way in which physicists understand the weirdness of quantum mechanics might be especially instructive as a crude template for how the consciousness story could play out. Physicists describe quantum mechanics by writing equations. The fact that no one, including them, can quite intuit the meaning of these equations is often deemed beside the point. The solution is the equation. One can imagine a similar course for consciousness research: the solution is X, whether you can intuit X or not. Indeed the fact that you can’t intuit X might say more about you than it does about consciousness.

Orr doesn’t seem to recognize how big a leap was involved in quantum mechanics.  Prior to the emergence of that field of physics, most scientific theory was resolute deterministic.  Every particle was at one place at one time and the state of every closed system rigidly determined the state of the system at all points in time.  Quantum mechanics allows particles to be in more than one place and state at one time and for authentically undetermined events.  If probability is not merely a limitation on our powers of prediction and instead something metaphysically real in the way that gravity is real, then materialism has a metaphysically new meaning. 

It might be that consciousness is simply something we cannot understand because our perspective as conscious creatures blinds us to it, a possibility that Orr considers.  It may be however that the nature underlying consciousness is, like quantum indeterminacy, something radically new to science.  If so, then Nagel is on to something. 

The lesser point of Nagel’s argument is that materialist biology is empirically wanting, as it is simply inadequate to explain the rise of complex forms of life.  Nagel suggests that only some kind of natural teleology can meet that challenge.  As Orr puts Nagel’s view:

Natural teleology doesn’t depend on any agent’s intentions; it’s just the way the world is. There are teleological laws of nature that we don’t yet know about and they bias the unfolding of the universe in certain desirable directions, including the formation of complex organisms and consciousness. The existence of teleological laws means that certain physical outcomes “have a significantly higher probability than is entailed by the laws of physics alone—simply because they are on the path toward a certain outcome.”

Orr responds with some very interesting summaries of evolutionary biology, including the difference between DNA and RNA.  I have no reason to quarrel with this except to point out that it should be possible to show mathematically that the complexity of life is within the powers of these simple molecules to produce.  Maybe it is, but has anyone show that it is?

Unfortunately, Orr fails to make a fundamental distinction between teleology as a factor in biological explanations, which he sort of acknowledges as reasonable, and teleology as a factor in the appearance of life on earth.  It is the latter that Nagel argues for.  Nagel says that scientists who study the origin of life generally believe that mere chance was insufficient to account for the emergence of the original replicators from which all other life evolved.  Is he right?  If not chance, then what?  I have consideredNagel’s argument on “unintentional forcing” as an explanation for the emergence of life.  Orr is silent on this. 

Orr’s review is respectful but is clearly intended to blunt the force of Nagel’s argument.  I have to say that, having read it, Nagel looks to be more rather than less worthy of taking seriously. 

Nagel's Neoaristotelian Teleology

In Chapter 4, Section 6 of Mind and Cosmos, Thomas Nagel adds a fourth kind of explanation for the existence of organisms, consciousness, reason, and value.  The first three I have considered in previous posts: chance, non-intentional biasing, and intentional biasing. 

Nagel considers all three to be inadequate.  He accepts the apparent consensus that the appearance of the original, proto-biological self-replicators cannot be explained by random processes.  He accepts Robert White’s argument that non-intentional biasing is not indicated because, while it can explain non-random patterns, it cannot explain a bias “towards the marvelous.”  This is to say that non-intentional biasing is no more likely to produce creatures or traits of creatures that look designed than mere chance.  Finally, he rejects intentional biasing in large part because he is an atheist. 

So what is left?  Nagel proposes a naturalistic teleology

that is distinct from all three of the other candidate explanations: chance, creationism, and directionless physical law. 

What does a “naturalistic teleology” mean?  When we try to understand any natural event, we look for ways in which the initial state of the system limits subsequent states.  A beaker of water can be frozen or heated to a boil, but not transformed into gold.  Lava under the earth can produce a volcano, but not Godzilla. 

Given any initial state of a system, some subsequent states are more likely than others.  It is rare, but not unprecedented, for mammalian evolution to move toward the development of wings and flight.  Some mammals returned to the sea and began to look a lot like fish; however, they did not develop gills.  This is what Daniel Dennett meant when he talked about “design space”.  At any point in the history of life on earth, a range of future organisms is possible.  As environments change, evolution will explore the possibilities in design space.  A population of lizards may change color to blend in better with new local vegetation, but the lizards will not acquire the power of genuine invisibility. 

Nagel proposes that the laws of physics underlying the appearance of life are biased towards “the formation of more complex systems”. 

Teleological laws would assign higher probability to steps on paths in state space that have a higher velocity toward certain outcomes. 

In other words, there is something in inorganic matter that is biased toward the development of something like human beings.  It smoothed the path toward the appearance of the Ur-replicators, and then toward the development of genuine organisms.  It has operated in evolution up to the appearance of philosophers. 

All I would add at this point is that Nagel has become an Aristotelian, if not a Platonist.  The Socratics clearly believed in an embedded teleology.  It is not, or not so much, that some God intervenes to govern the course of organic development.  It is that mind is already present in the forces that mold living things. 

That is a shockingly bold proposal.  How it can be maintained and/or squared with a scientific scheme seems to me to be a challenging question.  I don’t know if we can make sense of such an embedded teleology without a divine intention biasing the cosmos; however, if we forget about that question for a moment, this is a plausible picture of the history of life on earth. 

The Origin of Life, Chance, and a Biased Kosmos

Tonight I read “Does Origins of Life Research Rest on a Mistake?” by Roger White (NOUS 41:3 (2007) 453–477).  Nagel refers to this paper and White refers back to conversations with Nagel.  It is a very interesting read. 

White challenges a basic assumption that is apparently shared by almost all of those scientists who are trying to explain the origin of life.  Darwinian theory does very well at explaining the emergence of more complex and varied forms of life from simpler forms.  It depends, however, on the existence of self-replicating molecules that can come under the influence of natural selection.  What can explain the origin of the self-replicators? 

White presents the alternatives with an elegant metaphor: the three pebble patterns. 

Pebble Pattern 1: Pebbles are scattered in a disorderly fashion as we typically find them on the sidewalk. 

Pebble Pattern 2: At the English seaside, pebbles cover the beach in descending order of size toward the shoreline

Pebble Pattern 3: The pebbles are arranged to form a stick figure with a smile on its face.

Pattern 1 requires no explanation other than chance.  Random forces acting on the initial state (the prior position of the pebbles) produced the current state.  Call this the chance explanation. 

Pattern 2 shows a coherent pattern that does call for an explanation that involves more than chance.  The action of wind and wave select out heavier and lighter pebbles and place them accordingly.  Unlike the previous example, where the resulting state is largely dependent on the initial position of the pebbles, in this example it doesn’t matter much how the pebbles were distributed initially.  The forces at work will move them toward the same arrangement.  White calls this “unintentional biasing”. 

Pattern 3 shows clear evidence of intentional biasing.  Anyone looking at the stick figure will assume that someone intentionally arranged it to make a picture. 

White informs us that almost all of the origin of life theorists reject the chance explanation for the origin of the proto-organic molecules from which all living organisms descended.  The reason is that the emergence of such molecules by chance seems absurdly improbable.

We require one kind of chemical to be present, plus another very different one , and yet another different one , and we require the absence of still other substances. Certain chemical reactions must take place, then others involving different ingredients and producing different outcomes. A wide variety of events that would undermine the whole process must fail to occur. The molecular parts required to make up the replication machinery come in various sizes and structures. And they are not arranged in anything like a simple repetitive pattern but rather each has a very unique position and role to play.

Add to that the fact that the window of time in which this had to take place seems woefully inadequate to those that have looked at the problem with expertise.  To appeal to a familiar metaphor, the emergence of self-replicating organisms in the history of this planet is about as plausible as an army of chimpanzees, randomly striking their keyboard, turning out a copy of Richard III before lunch. 

Neither can the origin of life theorists appeal to intentional biasing (which is to say, intelligent design) as that seems strictly outside the realm of science.  So they have to believe in some form of unintentional biasing.  Something in the nature of the planet (and hence of the Kosmos) was biased in favor of the emergence of life just the tides are biased in favor of a certain arrangement of pebbles. 

White does not indicate whether he accepts the view that the appearance of self-replicating chemicals was as improbable as I put it above.  He just points out that most theorists regard it as so. 

His thesis is that the only reason to reject the chance hypothesis is that life looks like something that was intentionally designed and that fact provides no reason to believe in any natural, unintentional biasing mechanisms.  If I win the lottery despite implausible odds, I may feel as though I had been somehow favored over chance; it makes no case that the lottery is biased, intentionally or otherwise. 

I suspect that White is inclined toward the chance hypothesis.  Those of us who cannot buy it are only lottery winner who cannot believe that in our own good luck.  If the consensus is correct that luck is an implausible explanation, then his reasoning points in the direction of intentional biasing.  That pushes my theometer a couple of clicks in the direction of yes. 

Aristotle's Soul, Evolution, & Logos

In Chapter Four of Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature Is Almost Certainly False, Thomas Nagel turns to the mystery of human reason.  Before I comment, I will consider Aristotle’s tripartite model of the soul, from On the Soul. 

For Aristotle, the soul is the actuality of an organic body that has the potential for life.  To understand this concept, consider the question “What is a church?”  Is it bricks, boards, plumbing, and pews?  No.  Empty of people, it is merely a structure with the potential of being a church.  Is it the people who show up on Sunday?  No.  If the same people occupy the same building but are engaged in gambling and whoring, then it is a casino and a brothel, rather than a church.  The church is these people collectively worshiping.  Likewise, the soul is this material organized into, well, organs, and doing the things that living things do.  What do they do?

The most basic activities that characterize a soul are absorbing nutrients and producing waste.  If it eats and goes potty, it’s alive.  An essential character of soul is a dimension of value.  A being with a soul can survive and flourish or wither and die.  It can succeed or fail, something in which no rock is involved. 

This basic level of soul has been dubbed nutritive soul.  Aristotle thought that all living things have this kind of soul, but plants had this alone.  In addition to nutritive soul, animals have the capacity to move about and perceive at a distance.  Animal soul opens up a second existential dimension: pain and pleasure.  Apart from flourishing and withering (though to be sure, connected with the same) animals can have good and bad lives. 

Finally there is a third type of soul possessed by human beings alone.  In addition to nutritive soul and animal soul, human beings have logos.  An animal cannot distinguish between what it perceives and what is true.  Accordingly, no animal can distinguish between what it wants and what is good for it.  Human beings can make these distinctions, and that makes all the difference. 

Aristotle’s scheme is astonishingly easy to map onto an evolutionary account of the emergence of complex organisms.  Evolution does not replace simple forms with more complex ones.  Instead, it lays increasingly complex levels of organization on top of earlier ones.  Plants communicate within their bodies by the movement of fluids.  Animals do the same, but over those mechanisms are laid a system of nerves coordinated by a brain.  Human beings are animals.  Our capacities are laid on top of the capacities enjoyed by other mammals. 

Are we more than animals?  An obvious challenge to Aristotle is to say that he privileges human beings.  Isn’t our logos just a more sophisticated device for running the gauntlet of reproductive success?  Maybe. 

Nagel seems to agree with Aristotle that our rational capacity puts us in an entirely new category and that our reliance on reason cannot easily be explained in evolutionary terms.  More on that later.