Thomas Nagel: Constitutive Accounts – Reductionism and Emergentism

Thomas Nagel in his Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature Is Almost Certainly False starts from the premise that psychophysical reductionism, a position in the philosophy of mind that is largely motivated by the hope of showing how the physical sciences could in principle provide a theory of everything has failed to prove its case. As he states the case:

This is just the opinion of a layman who reads widely in the literature that explains contemporary science to the nonspecialist. Perhaps that literature presents the situation with a simplicity and confidence that does not reflect the most sophisticated scientific thought in these areas . But it seems to me that, as it is usually presented, the current orthodoxy about the cosmic order is the product of governing assumptions that are unsupported, and that it flies in the face of common sense.1

You notice the sleight of hand was move from “unsupported” to “flies in the face of common sense”. He seems over an over in his book to fall back on this common sense doxa approach when he’s unable to come up with legitimate arguments, admitting his amateur status as “nonspecialist” as if this were an excuse; and, then qualifying his own approach against the perceived “sophisticated scientific literature” as a way of disarming it in preference to his own simplified and colloquial amateurism.  The sciences of physics, chemistry, and biology are the key sciences that he wishes to use to prove his case. Behind it is a notion of a philosophy of “neutral monism” that he seems to favor: he tells us he “favors some form of neutral monism over the traditional alternatives of materialism, idealism, and dualism” (KL 71-72). As he tells it: “It is prima facie highly implausible that life as we know it is the result of a sequence of physical accidents together with the mechanism of natural selection. We are expected to abandon this naïve response, not in favor of a fully worked out physical/ chemical explanation but in favor of an alternative that is really a schema for explanation, supported by some examples.(KL 85-88)” To support his book’s overall theme he asks two major questions of the scientific community of reductionists:

First, given what is known about the chemical basis of biology and genetics, what is the likelihood that self-reproducing life forms should have come into existence spontaneously on the early earth, solely through the operation of the laws of physics and chemistry? The second question is about the sources of variation in the evolutionary process that was set in motion once life began: In the available geological time since the first life forms appeared on earth, what is the likelihood that, as a result of physical accident, a sequence of viable genetic mutations should have occurred that was sufficient to permit natural selection to produce the organisms that actually exist?(KL 89-93)

To answer the first question I took a look at the work of Jeffrey L. Bada, distinguished professor of marine chemistry at the University of California, San Diego, who studies the specifics of how life began on earth. He tells the story of his meeting with Stanley Miller, the chemist who, along with Nobel Prize-winning chemist Harold Urey, had discovered through experimentation a way to produce lightning and amino acids the building blocks of life:

In 1953, they completed the classic experiment on the chemical origins of life. They’d taken gases present on the early Earth like methane, ammonia and hydrogen and applied a spark discharge to them, to mimic lightning. From that, they produced amino acids, the compounds that make up the proteins in all living organisms.(NY Times: A Conversation With Jeffrey L. Bada)

He remarks that after meeting Miller he switch degrees and became a chemistry major. It was at this point that he performed as part of his Ph.D. an experiment under the supervision of Stanley Miller, telling us that he’d come up with a way to test the notion of stabilizing amino acid compounds in a laboratory experiment: “My Ph.D. idea was to move the spark discharge experiment a step forward by studying amino acid stability.” What was this so important? He says:

Because, in the turbulent environment of the early Earth, if an amino acid had been too unstable it would have decomposed. There would have never been enough of it to make up what we call “the prebiotic soup,” the molecular ingredients of life. So I suggested this one set of reactions that might constrain their decomposition, and then, in the lab, we did an experiment, which worked the first time we tried it. We were able to show some of the conditions that would allow amino acids to exist for longer time periods. And this allowed us to understand what types of amino acids may have been present on the baby Earth.(ibid.)

Next the interlocutor asks Bada how this discovery might prove how life came about. He tells us:

We are closing in on that question. The Earth had to cool down enough for water to appear. Water allows molecules to dissolve and interact, which is why it is essential to life. We do know that we went from simple molecules to more complex molecules and eventually to RNA, which evolved into DNA. This took about a billion years.

The missing piece of the puzzle is that intermediate phase between the amino acids and the RNA phase. We know that RNA is too complex to have arisen out of the simple molecules of the primordial soup. We can surmise that this intermediate form was able to make copies of itself to pass onto the next generation. Over time, mutations occurred and those mutants with survival advantages thrived and on and on until you eventually got to the complex RNA world.(ibid.)

Eight years after the original experiment Bada received a pleasant surprise when his former teacher on retiring left the original lab work to his former pupil. What Bada did was to reanalyze the data with newer apparatuses and to his surprise in the original experiment they had discovered only four compounds, but on reviewing the same data with newer technologies he’d discovered 30 new compounds: “We have instruments today that are a billion times better. So we then reanalyzed the original materials with the modern tools. And lo and behold, we found that the spark discharge experiment had actually made about 30 compounds. Stanley had shown they’d made only five!” At this point the interlocutor asked if the redid the experiment again, because some skeptics in the scientific community felt it had not been validated. Bada says: “Oh, yes. And more! It showed how easy it was to make a huge number of compounds. What was really interesting was the Murchison meteorite, which fell to earth in 1969, was originally thought to contain maybe 75 amino acids. Three years ago, when we compared the distribution of amino acids in the discharge experiment, they were uncannily similar to those in the meteorite.”(ibid.)

Asked if other scientists should continue pursuing this, Bada says:

Listen, I was very fortunate to have had a mentor who had the foresight to preserve his experimental materials. Nonetheless, he couldn’t anticipate all the changes that came with modern analytical chemistry. Today, we are seeing an explosion of knowledge due to new techniques. We ought to use them.

There was just an article in the journal PNAS about how new methods further characterized the compounds in Murchison. Up to now, we knew of hundreds in it. Yet, because of new techniques, they’ve found tens of thousands. And that made me think that yes, we ought to redo the spark discharge experiment. I suspect we’d also find tens of thousands of molecules that were in the prebiotic soup. That, hopefully, is the next project we’ll be pursuing.(ibid.)

Searching Nagel’s book I was unable to locate any reference to the studies by Stanley Miller and Harold Urey, nor was Jeffery L. Bada mentioned either. Most this was common knowledge over nine years ago. So Nagel either missed or conveniently left out such scientific findings so that he could prove his case of common sense speculation on emergentism.

After realizing the Nagel hadn’t bothered to do his homework and actually discover what real world scientists were doing at this juncture in history I thought, ok – maybe, just maybe he missed the boat, somehow missed this one, an oversight on his part, so we’ll move on to the second question which is more pertinent to evolutionary theory (and I requite):

The second question is about the sources of variation in the evolutionary process that was set in motion once life began: In the available geological time since the first life forms appeared on earth, what is the likelihood that, as a result of physical accident, a sequence of viable genetic mutations should have occurred that was sufficient to permit natural selection to produce the organisms that actually exist?(KL 89-93)

First one needs to ask what his criteria of “viable genetic mutations” consists of? He isn’t concerned with the mechanism by which this process gets going, but seems concerned more with the temporal manifestation for such mechanisms as if to say: the mechanisms of evolutionary theory do not support the needed genetic mutations for this process within the temporal timespan of present evolutionary theory. And I would ask: By what criteria did you define this question? Was this some probabilistic mathematical procedure and analysis of the present data in evolutionary theory that presented you with such a question? Or, are you saying the mechanism of natural selection and genetic mutation could not produce such variations as we see today and in history in this temporal timespan? Or, is it the accidental nature of these processes and the explanatory principles of genetic mutation and natural selection that disturbs you? Is his questioning of the nature of accident as an explanatory principle another attack from design? Is he seeking to put some hidden teleological or more likely theological principle back into place? And what is this “neutral monism” that he so cherishes?

Since his attack was on idealism, materialism and dualism and an effort to replace these with what he termed “neutral monism” I thought it we would better be served to understand just what this non-reductionist or irreductionist monistic philosophy consisted of. He starts with the two questions he first raised and tells us that his skepticism is “not based on religious belief, or on a belief in any definite alternative. It is just a belief that the available scientific evidence, in spite of the consensus of scientific opinion, does not in this matter rationally require us to subordinate the incredulity of common sense” (KL 97). He tries to build a case that our current reductionis cosmology and biological thinking have been reduced to a set of probabilistic theories based on a static conception of synchrony rather than the diachronic or historical account that is needed for a fully comprehensive view of the sciences:

It seems inevitable that such an understanding will have a historical dimension as well as a timeless one. The idea that historical understanding is part of science has become familiar through the transformation of biology by evolutionary theory. But more recently, with the acceptance of the big bang, cosmology has also become a historical science. Mind, as a development of life, must be included as the most recent stage of this long cosmological history, and its appearance, I believe, casts its shadow back over the entire process and the constituents and principles on which the process depends.(KL 116-120)

His point being as he states it: “I have said, doubts about the reductionist account of life go against the dominant scientific consensus, but that consensus faces problems of probability that I believe are not taken seriously enough, both with respect to the evolution of life forms through accidental mutation and natural selection and with respect to the formation from dead matter of physical systems capable of such evolution” (KL 125-128).

So in the above he attacks the mathematics of probabilistic accounts as well as the notion that life could arise out of “dead matter”. So he’s attacking the mechanistic world-view as he sees it. But what would he replace it with? This is where it gets interesting in that Nagel poses against constitutive accounts of life and evolution the opposing views of reductionism and emergentism:

A reductive account will explain the mental character of complex organisms entirely in terms of the properties of their elementary constituents, and if we stay with the assumption that the mental cannot be reduced to the physical, this will mean that the elementary constituents of which we are composed are not merely physical.  Since we are composed of the same elements as the rest of the universe, this will have extensive and radical consequences, to which I will return below.

An emergent account, by contrast, will explain the mental character of complex organisms by principles specifically linking mental states and processes to the complex physical functioning of those organisms— to their central nervous systems in particular, in the case of humans and creatures somewhat like them. The difference from a reductive account is that, while the principles do not reduce the mental to the physical, the connections they specify between the mental and the physical are all higher-order. They concern only complex organisms, and do not require any change in the exclusively physical conception of the elements of which those organisms are composed . An emergent account of the mental is compatible with a physically reductionist account of the biological system in which mind emerges.(KL 699-705).

The tricky part of the above is that Nagel has slipped from a scientific enquiry into a metaphysical enquiry but elided the knowledge of that move for the wary reader. The point being in his account is the metaphysical question of whether our mental states (consciousness) do or do not have powers and capacities of their own. In the reductionary account the do not, in the emergent account they do. Now in metaphysics there is a large debate regarding this type of thinking between reduction or emergence.

Let’s take a look at the problem of emergence and see what current neuroscientists tell us. We can break it down into four primary forms:

  1. We are conscious beings.
  2. We are composed entirely of nonconscious parts.
  3. No number of nonconscious parts could combine to produce a conscious whole.
  4. The properties of a whole are determined by the properties of its parts.

The notion that we are conscious beings is rejected by elminativists. They deny there is any such thing as consciousness, and hence, that we are conscious beings. As for number two certain dual-attribute theorists – panpsychists and panprotopsychists in particular – reject this claim. They claim that the entities that compose us, including fundamental physical particles, have conscious or protoconscious states. Also substance dualists, idealists, and nonorganismic dual-attribute theorists also reject number two but for different reasons. They deny that we are composed of physical materials at all. Many emergentists and epiphenomenalists, by contrast, reject claim number three; they claim that consciousness emerges from nonconscious materials by virtue of brute psychophysical laws. Reductive physicalists also reject number three. They look to identify conscious states with complex relations among physical particles. Consequently, if enough physical particles stand in the right relations, there are conscious states. Neutral monists and nonreductive physicalists (of which Nagel is one) say something similar. The relations between conscious states and physical particles are not as straightforward as reductive physicalists suppose, they say, but whenever we talk about conscious states we are still talking about complex relations among physical or neutral particles. Hylomorphists, on the other hand, reject claim number four (Aristotle). Living wholes, they say, are structured in ways that confer on them capacities not had by their parts – including the ability to be conscious. Something’s structure, however, is not produced or determined by the materials it configures; structure is instead a basic ontological and explanatory principle in addition to those that govern materials in their own right. Finally, some mind–body pessimists claim that the problem is insoluble, that there are absolute limits on our ability to know and understand the world, and these limits manifest themselves in philosophical problems that cannot be solved like this one. Instrumentalists, on the other hand, do not insist that the problem cannot be solved but emphasize that it need not be solved. Psychological discourse is a useful tool, they say, and we need not solve mind–body problems to continue using it.2

The knowledge claims put forward by those scientists in each of these camps must offer up specific criteria and reasons for rejecting other alternative theories, and this in itself is a daunting task. Yet, knowing where Nagel is situated in this ongoing debate among neuroscientists helps us to understand better how to question his claims against the reductionist theories he sees as his focal point. One of the keys to Nagel’s analysis is his belief in intentionality and that it cannot be explained away or reduced to physical processes:

…human consciousness is not merely passive but is permeated , both in action and in cognition, with intentionality, the capacity of the mind to represent the world and its own aims. It may be more controversial to claim that intentionality cannot be realized in a purely physical universe than that consciousness cannot be. However, if, as I believe, intentionality, thought, and action resist psychophysical reduction and can exist only in the lives of beings that are also capable of consciousness, then they too form part of what a larger explanation of the mental must account for.(68)

Already he twists the knot, in effect saying that there are intentionality (the aboutness of directed consciousness) exists and that there are only certain types of beings capable of such consciousness. Why must we think consciousness is intentional? Is this a bias? The elminativist would say this concept is overrated and not needed as an explanatory principle. Such eliminativist practioners as Paul Churchland whose own brand of reductionary science he terms ‘intertheoretic reduction,’ tells us that such methods and their “epistemological significance resides foremost in the fact that, if we have presumptively overlapping pairs of maps, then we are in a position to compare their respective depictions or portrayals of their shared domain , and to evaluate them for their accuracy, their comparative detail, and their possibly diverse representational concerns. We have been doing this for centuries, without fully appreciating just what we were doing” (KL 4371).3 The point being that Nagel is possibly attacking a straw dog, a fictional reductionism that for purposes of polemic he has set up so that he can not only knock it down but replace it with his own account. But what is his account? What is this emergentism of which he champions? And, does it hold up to scrutiny?

I’ll need break here and take up this question in another post…

1. Nagel, Thomas (2012-08-29). Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature Is Almost Certainly False (Kindle Locations 68-69). Oxford University Press. Kindle Edition.
2. Jaworski, William (2011-07-11). Philosophy of Mind: A Comprehensive Introduction (Kindle Location 610). Wiley. Kindle Edition.
3. Churchland, Paul M. (2012-03-09). Plato’s Camera (Kindle Locations 4371-4373). MIT Press. Kindle Edition.

3 thoughts on “Thomas Nagel: Constitutive Accounts – Reductionism and Emergentism

  1. I’m convinced that ‘reductionism’ is largely a canard. Everyone but everyone buys into reductionism in the analytic sense, that the royal road to knowledge of nature consists in taking things apart and seeing how they tick. But thanks to information technology we have other ways of gleaning information at different scales. The examples of clean ‘theoretic reduction,’ on the other hand, seem few and far between. I personally think it would be amazing, given our limitations, if we ever found one theoretical idiom to ‘explain everything’ – at least that we ourselves could understand! I think the best way to look at the general divide you cover in terms of competing families of naturalisms, with lots of crossbreeding in between. So on the one hand you have the ‘there’s gotta be more’ naturalists, and on the other, the ‘stick to the razor’ naturalists.

    So for me, the debate actually has very little to do with ‘reductionism,’ and everything to do with the efficacies of various epistemic modalities. So my thesis, for instance, is just that there isn’t any such thing as consciousness *as it appears to reflection,* and that a lot of the problems plaguing cognitive science and philosophy cound be cleared away if we came to see this. I think we’ve duped, and the range of things I think we’ve been duped about qualifies me as a rather extreme eliminativist. I think pretty much the whole of our second-order speculative discourse relies on a series of what are best described as metacognitive illusions.

    Since I’m a ‘stick to the razor type,’ Nagel’s brand of ‘can’t get there from here’ emergentism argument for the ‘there’s gotta be more’ camp strikes me as an exercise in rebranding our ignorance in a way friendly to his side, and not much more. The same goes for arguments like Rosenberg’s in The Atheist’s Guide to Reality, which boils down to, ‘Science can’t make heads or tails of this stuff so it’s crap’ eliminativism. Trodden ground. I’m much more interested in emergence arguments like Evan Thompson’s in his Mind in Life or Deacon’s Incomplete Nature, where reconceptualizations are paired with considerations of the sciences at issue, and some kind of *positive thesis* for how emergence might work is put forward.

    I’m presently finding Deacon’s book a fascinating, even eerie read. He very much sees the problem of meaning the way I do, and he sees the task for any successful emergentism in terms parallel to the way I see the task for any successful eliminativism. But I’m having the same difficulty with him that I had with Thompson: even granting them their complications of causality (to account for different kinds of complex systems), for the life of me I don’t see how any of it gets them any closer to actually naturalizing intentionality as opposed to offering theories of the complex causal structures pertaining to life and mind. Global-to-local causality (Thompson) or abstential constraints (Deacon) do nothing more than give us a more nuanced picture of mechanism – obviously so, I think! – whose complexities render them semantically ductile enough to kinda sorta see how they might ‘fit’ this or that intentional mode.


    • What you seem to be saying is that part of this post-intentional theory is the need for a ‘theory of meaning’ that both clears up the muck of intentionality once and for all, and offers a replacement theory of meaning that is neither nihilist nor intentional? And, none of the above do that: they all seem to skirt around and dodge the issue rather than hitting it on the head with a sledge hammer?

      Yea, in my search around the continental and analytical worlds I find everyone going from one extreme to the other like Jaegwon Kim who started as an extreme physical reductionist and is now its opposite. A merry-go round… What your suggesting is we get off the merry-go-round and blow the dam thing up and be done with it once and for all…

      The causal problem always boils down to one thing: How do things ever get going anyway? Otherwise we’d live in a dead, static universe… Obviously the Occasionalist would say it is God that does the trick… Hume played this down, but borrowed a weak version of this from Malbranche. So far most people skirt the issue as a non-question. But if we are to explain the intricacies of the brain and its interactions with the structures of reality we have to answer that question. I mean is everything material, or is everything mental: the old battle of the Parmendian Way, or the foundry of aporia: the non-meaning of everything inexplicable. I mean with emergentism and your eliminativism it sounds close to some form of Idealism in the sense that Parmenides said ‘thinking and being are one’… for you to eliminate consciousness, then what does the thinking? Do these sub-systems think us moment by moment? Hume again but with science to actually explain it? Is it just an emergent process of a series of sub-components all the way down that emerge and make decisions or choices… is the structure of the brain and the structure of reality one and the same? Or is there another explanation? And, if so, what makes us get up and move in the morning, pretend with ourselves that we’re actually alive, loving our wife and kids, going on with our daily lives as if we actually existed in first person singular when according to you this is just the Grand Illusion? Are we puppets on a string: determined from the get-go? Is every decision we make just another lie of our sub-cortical component systems within systems? And, if so, then why would ‘meaning’ matter if there is no one home – no intentional consciousness to care?


  2. Pingback: The Sciences: Reductive or Anti-Reductive Theories? | noir realism

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