Evolving Thoughts

As I have argued before, there is a class of objects in the biological domain that do not derive from the theory of that domain, but which are in fact the special objects of the domain that call for a theoretical explanation. The example I have given is mountain, which is a phenomenal object of geology, and yet not required by the ontology of any geological theory, which does include overfolds, tectonic plates, upthrusts, the process of differential erosion, and so on. At the end of the theoretical explanation, the mountains have not disappeared so that we might now drive from Arizona to Los Angeles on the flat, but they are fully accounted for.

Much ontology in special sciences is of this kind: listing phenomenal objects. Sometimes a phenomenal object is something that is merely salient to us as organisms. Mountains are things we must navigate over or around. They have a more than epistemic status. They are, in this case literally, a distribution of measurements (of elevation in this case). The measurements are objective in the sense that any measuring device properly calibrated will give the same results for any observer. I will call this assay objectivity – a phenomenon is assayable in a fashion that is not subjective. I do not say there is a mountain there because it seems to me there is. I say there is a mountain there because there damned well is, and anyone who want to deny it had better be able to account for their elevation when the rest of us say they are at the peak.

There are, famously, other senses of phenomenality that can be constructed in ways that are culturally relative, or subjective (note: subjectivity and relativity are not the same). Infamously, some phenomenal objects are entirely constructed by observers, like… well it’s actually hard to come up with examples. Even in cases like “race” there are underlying distributions of assayable data – the moreso in these days of geographical distributions of alleles. Race may be a construct, but it is not a construct with only political underpinnings; there really are differences in, say, resistance to malaria and susceptibility to sickle cell anemia. Perhaps the difference between Catholics and Protestants is a pure construct, but it is not, so far as we can tell, a difference we ascribe to biology (now) anyway. [To head off the obvious objections: I do not believe races exist in the human species, as by the usual criteria for races in biology humans lack the requisite variation; our "races" are political, social, geographic and phenotypic constructs based on actual but fairly shallow differences. A single troop of chimps has more genetic variation than the whole human race (can anyone find the citation for that claim, by the way?). There are differences, but not persistent or deep enough to warrant calling these groups races.]

Phenomenal objects are in effect specified by the prior existence of the special domain in which they are recognised. If you have a domain “biology”, then objects that routinely appear in that domain, like “organisms”, are specified as objects of that domain. In an extreme reductionist approach, in which everything is physics, this is tantamount to saying “some physical systems get called organisms”. That is, these are just another way in which physics plays out. Like black holes, G class stars, and, yes, mountains, they aren’t “really” objects of a special domain. So on a strong reductionist view, one ought to deny that these phenomenal objects are, in fact, special objects of the domain at all. Of course, a strong reductionist approach says the same thing about theoretical objects as well.

The conundrum we have is this: if we do not want the phenomena to simply be arbitrary and instrumental artifacts of our limited epistemic capacities, if we don’t want these things to be “real” just so far as we cannot make the proper inferences from physics to organisms, etc., we need some reason to think the domain is a domain apart from a mere implementation of physics. Or is Rutherford right when is said “In science, there is only physics. All else is stamp collecting”? How can we be physicalists and not merely stamp collectors in biology?

One way is emergentism. This is the view that there are properties at some levels that, while they involve physical objects and only physical objects, arise at a level of complexity. These properties are said to be emergent properties. There are several versions [pdf] of emergentism – the one I am interested in here is systemic emergentism, which Stephan in the previous link defines thus:

Emergent properties are systemic properties. A property is a systemic property if and only if a system possesses it, but no part of the system possesses it.

The important features is that the property must be a system property, which implies for any domain that there are systems in that domain, and that a simple physical enumeration of all the parts of that system will not give you the property. So we have a couple of implications. First, there is a system class in the domain (e.g., organism), and second that there are properties of that system that are not properties of the components which it or any other system of the same class comprise.

Having system properties, however, might be something fairly innocuous for a reductionist. They might be simple epiphenomena – properties that are merely formal and have no causal power. I think we can assume that we want our properties to be causal, and on a reductionist account like Rosenberg’s, these system properties are not, in the final analysis, causal. That is, there is no downward causation, from one higher level to the lower level. An example might be that there is no system property that makes molecules of nucleotides recombine when an egg of a vertebrate is fertilised. All the causation happens at the physical level. Actually, I should scare quote “physical level” here; if we assert there is a single physical level we are begging the question in favour of reductionism.

The problem I have with emergentism is that is, too, resolves in my view, to epistemic properties. To explain this I should use a physical example – a case in which some property was thought to emerge at the “physical level” from physical component properties – water. You’ll find this in Mill’s System of Logic (Bk I, ch VI). After suggesting that we can inductively infer the properties of objects from their components, he says (p426ff):

This principle however by no means prevails in all departments of the field of nature. The chemical combination of two substances produces as, is well known, a third substance with properties entirely different from those of either of the two substances separately, or of both of them taken together. Not a trace of the properties of hydrogen or of oxygen is observable in those of their compound, water. The taste of sugar of lead is not the sum of the tastes of its component elements acetic acid and lead or its oxide; nor is the colour of green vitriol a mixture of the colours of sulphuric acid and copper. This explains why mechanics is a deductive or demonstrative science, and chemistry not. In the one we can compute the effects of all combinations of causes, whether real or hypothetical, from the laws which we know to govern those causes when acting separately; because they continue to observe the same laws when in combination, which they observed when separate: whatever would have happened in consequence of each cause taken by itself, happens when they are together and we have only to cast up the results. Not so in the phenomena which are the peculiar subject of the science of chemistry. There, most of the uniformities to which the causes conformed when separate, cease altogether when they are conjoined; and we are not, at least in the present state of our knowledge, able to foresee what result will follow from any new combination, until we have tried it by specific experiment.

Or so it stood in 1843. Now, not only can we predict the general properties of water from a knowledge of the properties of elements, and in fact the particular microstructural properties of water in special cases – why there is a structure in cells and water in containers, etc. What changed? Well, obviously the valency theory of elements is the major change, but even then Mill might have said we cannot make the predictions. The real (or actually “unreal”) change here lies in the rapid expansion of our own computational abilities. We now have computers that can predict the behaviour of water at the microlevel, and thus the overall “liquidity” that had remained imponderable in Mill’s time, and for thousands of years prior to him.

So at some point, our computational capacities make the shift from “inferable” and “predictable” to “emergent” and “unpredictable”. Emergence is thus, in my view, a matter of what information theorists call “surprisal” – which is a measure of the expected observation compared to the actual observation. An emergent property is one that surprises us, in short. This means it doesn’t solve our problem, for it is a matter of epistemic limitations, not ontology.

Incidentally Mill goes on to make an explicit link to biology – the term “organised bodies” here is a previous term in common use before “organism” was introduced into English from the French:

If this be true of chemical combinations, it is still more true of those far more complex combinations of elements which constitute organised bodies; and in which those extraordinary new uniformities arise, which are called the laws of life. All organised bodies are composed of parts, similar to those composing inorganic nature, and which have even themselves existed in an inorganic state; but the phenomena of life, which result from the juxtaposition of those parts in a certain manner, bear no analogy to any of the effects which would be produced by the action of the component substances considered as mere physical agents. To whatever degree we might imagine our knowledge of the properties of the several ingredients of a living body to be extended and perfected, it is certain that no mere summing up of the separate actions of those elements will ever amount to the action of the living body itself.

It is not so certain in 2008. This must give us pause when we try to consider a priori what is and what is not explicable in terms of physical components. And the explanations we give now are causal at the physical “level” (that is, in terms of molecules, and physical forces like the Strong and the Weak force, and van der Waals forces). So I reject emergentism as a solution.

A variation on emergentism is holism, in which there just are properties of wholes, and they are irreducible. A view closely associated with Arthur Koestler, I believe this is – like the vitalism with which is it closely related – a dead issue. It is very popular amongst mystics and theologians, but not so much amongst scientists, although often views get called holistic which are just instrumentalisms, which make of epistemic necessity, ontological virtues. “Whole organism” biologists need not be holists, so long as they understand what they are protecting is the instrumental value of studying things at one scale of description because (as we saw for emergent properties) it is a limitation of our cognitive capacities that we cannot start at the “bottom” and work up.

So we seem not to have a solution for reductionism. If a domain is phenomenally salient, and the resultant science is special just because it serves us to study it, it looks like we don’t have an ontology for the special sciences. So what do we say? I think we just suck it up and say that an ontology need not be irreducible. We do have a domain of biology; if it is just a phenomenal domain, in which all its laws or generalisations are reducible to physics, so what? We now need a science of biology. We now need a science of geology, and other historical sciences, and while they may all one day be easily reducible to physics (I doubt it) they aren’t now. So we are entitled to say that biology contains organisms and other objects, only some of which are derivable from theories of biology.

This also means we should not worry too much that we have no exceptionless laws of biology that are not laws of physics. Not every science need be physics all the time We still want to know about the biological realm (and all those other special science domains). It may be stamp collecting to a theoretical physicist, but it is very interesting stamp collecting. It is not trivial to discover how a species of organism behaves in an environment. Nor is it trivial to discover how a particular kinase sets off a signal cascade that results in the death of an otherwise healthy cell, and so on. These are interesting phenomena and explanations. This is an increase in our knowledge. So screw the physicists. They are to be appealed to only when it helps us understand biology (if you are biocentric as I am). Otherwise, they can go argue over string theory, while biologists get to the business of understanding the macroworld around them.

Comments

  1. #1 Phil Grimm
    November 15, 2008

    I agree with you–I think. I have stumbled upon your blog, and find out that you and I are thinking along the same lines, but your thoughts are so densely packed with content that they take time to digest.

    My issues of emergentism and surprisal concern my developing theory of Humanity: that there is a triad; the Homo sapiens (a living biological creature), the Human soul (also a living biological creature), and that both of these are artificially tethered together {the subject of a much longer and more detailed discussion}, these two together form a service-service mutualism, functionally creating a ”hybrid’ energy field’ that is what we call the Human Being. That the entity that we know of-and take for granted as being a single organism- as the Human Being, is not really a living biological creature at all. And that there is a significant surprisal factor in the Human Being when compared to its component part: the Human soul and the Homo sapiens.

    Anyway–you may disagree. And maybe I have misinterpreted your thoughts, and maybe I am full of shit.

  2. #2 John Morales
    November 15, 2008

    I suspect the chimps dictum is a misquote from a 2002 AP story:

    “Chimps show more genetic variation than humans in all areas – with this one exception, which is seriously condensed,” said Dr. Ronald Bontrop, who led a Dutch team that worked with statisticians from the University of California.

  3. #3 Tim Eby
    November 15, 2008

    John;
    You ask the question “How can we be physicalists and not merely stamp collectors in biology?” and then reject “emergentism” as a possible partial answer.

    If I understand your argument correctly, you assume that the fundamental laws of physics are mathematical in nature and therefore the behaviour of a physical system can be predicted by mathematical operations. (“So at some point, our computational capacities make the shift from “inferable” and “predictable” to “emergent” and “unpredictable”.” …… “And the explanations we give now are causal at the physical “level” (that is, in terms of molecules, and physical forces like the Strong and the Weak force, and van der Waals forces).”

    In other words, you conjecture that the properties of a finite collection of particles subject to the laws of physics are completely fixed once the initial conditions are specified.

    However, P C W Davies (Australian Centre for Astrobiology, Macquarie University,New South Wales) makes what I think is a very convincing argument in “Emergent Biological Principles and the Computational Properties of the Universe” (arxiv.org/pdf/astro-ph/0408014) that this conjecture may not be true of all physical systems. Davies points out that…

    “Another school of thought, represented most notably by Wheeler (1984) and Landauer (1967, 1986), stresses that real calculations involve physical objects, such as computers, and take place in the real physical universe, with its specific available resources. In short, information is physical. That being so, it follows that there will be fundamental physical limitations to what may be calculated in the real world, which in turn imposes fundamental limitations on implementing the laws of physics, even in principle. Landauer adopts the position that these limitations are not merely a practical inconvenience, but determine the very nature of physical law (Landauer, 1967):”
    … and… “The calculative process, just like the measurement process, is subject to some limitations. A sensible theory of physics must respect these limitations, and should not invoke calculative routines that in fact cannot be carried out.”

    Thus, according to Landauer, if something cannot be calculated, even in principle, within the real universe, then we cannot legitimately regarded it as an application of physical law.

    Davies goes on to argue that while “… there are indeed cosmological models for which there are no limits on the information content and processing power of the universe. However, recent observations favour cosmological models in which there are fundamental upper bounds on both the information content and information processing rate. A Landauer-Laplacian demon associated with such a cosmological model would perforce inherit these limitations, and thus there will exist a fundamental bound on the predictability of complex physical systems, even in principle, if one adopts the Landauer-Wheeler principle of physical law.”

    Davies then presents a quantitative ( and not too mathematically sophisticated) discussion after which he concludes that:

    “….. The results suggest that the key molecules for life – nucleic acids and proteins – become biologically efficacious at just about the threshold predicted by the Landauer-Wheeler limit corresponding to the onset of emergent behaviour, and that therefore their efficacy may be traced in part to the operation of as-yet-to-be-elucidated biological organizing principles, consistent with, but not reducible to, the laws of physics operating at the micro-level. This analysis therefore supports the contention that life is an emergent phenomenon.”

    In light of modern cosmology, your rejection of emergence may be premature.

  4. #4 John S. Wilkins
    November 15, 2008

    Tim: First off, Paul Davies is now at Arizona State U.

    I do not think that the universe is mathematical in nature, nor that we can make determinate calculations based on laws and initial conditions. This is way too much of an overinterpretation of what I think and said. In fact the view that Wheeler is sometimes associated with, that the universe actually is information is a bad mistake – it puts the mental map in front of the causal fact. I think information is derivative of the physical. However, nothing much is gained by calling physical systems computational even if all computational systems are physical.

    But granting Davies and Wheeler and Landauer doesn’t materially affect my view. The “emergent” threshold is just where some process surprises us in its outcome. The physical reality remains physical, and all physical properties are aggregates of the primary physical properties of the system’s parts, in its physical context. If “life” is an emergent phenomenon (and I am not saying there are no properties that emerge, only that they are not ontologically important), note that Davies himself still talks in epistemic terms: “it cannot be reduced to the laws of physics”. By whom? By us now? Sure. By God or the Final Physicist? I rather doubt it. To assert otherwise is to deny the unity of the universe. While that is a possible solution, it is not one I want to adopt. I think the universe simply is comprehensible in terms of a basic physics, even if we cannot, in special cases, make the inferences in detail.

    To put it another way, the laws of physics either explain physics or not. If they do, then everything that is physical is reducible to them (including, I reckon, mathematics, but I can’t argue for that in detail). If they don’t, then we are in a bad way.

  5. #5 Jonathan LaTourelle
    November 16, 2008

    Dear John:

    How can you argue for the actual physical existence of things. You assert it quite frankly: “I don not think that the universe is mathematical in nature, nor that we can make determinate calculation based on laws and initial conditions.” I might say that such calculations at present are dubious but not fundamentally wrong. And, what is more, fundamental particles are in principle only understandable though mathematical models. Maybe what I’m not understanding is the distinctions you make on epistemological v. ontological grounds? It seems like if we have no way of knowing that something actually is it makes little sense to talk about its ontological virtues granted to it by our -people- limited epistemic capacities.

    In any case, it always surprises me that honest philosophers -or whatever we call our selves- persist in the orthodox opinion that things just are physical.
    I don’t mean to get you into some kind of debate about Berkeley or any other traditional ‘idealist’ or ‘dualist’ or such (because I think Berkeley and his lot are wrong); so instead I’ll just remind that Newton, after describing forces (gravity and all his other crazy forces), came to the reasonable conclusion that there was no evidence for bodies at all. Because 1. how can we have action at a distance and 2. how can non-material things, like magnetism, have material, causal, effects. I know everyone gets mad when people talk about action at distances because our models now articulate the facts differently – but, as far as I understand, (which isn’t all that far) any objective examination of our models would lead to the statement that ‘in the world there is action at distances.’

    Perhaps I am undereducated but it seems to me that your statement about ‘things really existing’ in them selves, is perhaps not founded upon evidence other than a ‘common sense understanding’ of the world.
    I’ve been a big fan of Einstein for many reasons: the one germane being his reminder that our common sense understandings of the world has very little to do with what is actually going on.
    I’d love to hear your thoughts.

  6. #6 Pierce R. Butler
    November 16, 2008

    These are interetsing phenomena and explanations. This is an increase in our knowledge. So screw the physicists.

    Egad.

    The only remaining question is whether Wilkins has become a raw utilitarian or a raving hedonist.

  7. #7 Russell
    November 16, 2008

    John S. Wilkins:

    Mountains are things we must navigate over or around. They have a more than epistemic status. They are, in this case literally, a distribution of measurements (of elevation in this case). The measurements are objective in the sense that any measuring device properly calibrated will give the same results for any observer. I will call this assay objectivity – a phenomenon is assayable in a fashion that is not subjective. I do not say there is a mountain there because it seems to me there is. I say there is a mountain there because there damned well is, and anyone who want to deny it had better be able to account for their elevation when the rest of us say they are at the peak.

    What some people see as mountains, others see as mere hills, or a butte or even a ridge. The boundaries of any particular mountain are subjective, and even whether it is one or two or three. Yes, of course, we have to climb up and down regardless. But you were proposing to solve the problem of scientific ontology, and as far as I can see, all you have done is said that some things in the ontology of particular domains, such as geology, are inherited from common language. Without even noticing that the domain specialist may shift the concept quite a bit, i.e., a geologist may have a notion of mountain that is more based on the process by which it was formed than by what it looks like, and so what locals called a mountain, because of its shape, the geologist labels a butte, convinced that it was formed not by uplift but by the rest of the land around it being worn away by erosion.

  8. #8 John Morales
    November 17, 2008

    Pierce @#6, I think it’s just an obscure joke.

    Physicists are, after all, natural philosophers

  9. #9 Pierce R. Butler
    November 18, 2008

    Physicists are, after all, natural philosophers…

    But are they utile or hedonic? More research is needed!

  10. #10 John Morales
    November 18, 2008

    Thanks for reminding me of how dense I am, Pierce :)

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