Pizza reductionism, emergence and phenomena

Debates over reduction in science are as old as philosophy of science, but in the 1960s, Ernest Nagel’s book The Structure of Science really set things going. Nagel argued that a goal of science was to reduce one theory to a more general and explanatory theory, so that one can deduce the laws of the reduced theory from the laws of the reducing theory given enough time and computational capacity (Rosenberg 2008). The example he used and which has been the standard one since is chemistry and physics: all chemical entities and processes can be reduced to more general descriptions in physics (ideally). This was extended to biology (Brigandt and Love 2008), psychology and cognition, in what has come to be called “layer cake reductionism” by Ken Waters (2008) in contrast to “layer cake antireductionism”, a form of holism that insists that every layer of the ontic cake is somehow self-subsistent or emergent. It is a particularly sharp issue when discussing genetic relations to the phenotypic traits of organisms: genie reductionists often seem to, or sometimes actually do, assert that the properties of the organisms as a whole are the properties of genes.

The idea of a hierarchy of ontological layers can be diagrammed like this:

Layer Cake Reductionism

The idea is twofold: for reductionists, each theory or law of one layer can – in principle – be redescribed and/or predicted from the laws and theories of the next deepest layer. For antireductionists – variously called holists or emergentists – each layer has qualities, properties or laws that cannot be so reduced. Biologists like Ernst Mayr, for example, who thought that biology was a science independent of physics, hold that phenomena at higher levels are sui generis and cannot be reduced. This is often thought to be the justification for biology being a science on its own at all (it isn’t; what counts as a science has more to do with shared histories of the discipline and special methodologies than anything really deep).

Layer cake reductionism gets made fun of, as in this cartoon by xkcd:

… and sociologists will assert that mathematics is just applied sociology. However, there’s a mistake of reference in this. It suggests that physics is mathematics, but the term “physics” here equivocates over whether we are referring to the subject of physics (i.e, the physical world), or the method and knowledge of physics (i.e., our theories of physics). The physical world remains whatever it is even if we don’t have the epistemic tools to find out about it or to predict higher level properties from physics. In short, limitations in ourselves as cognitive systems should not be projected to the world we cognise. If we describe the physical in mathematics, that does not mean, pace Wheeler, that the world is mathematics (a view that goes back to Pythagoras’ followers if not the man himself). It means that we represent and understand the world in mathematical terms. I therefore reject what is called Mathematical Platonism. Typically we distinguish between the ontological, methodological and epistemic forms of reductionism (but I think the methodological are epistemic; Brigandt and Love 2008). These are, respectively, the reduction of: types of things, ways of investigating things, and relations of domains of knowledge. I’m only really interested in the ontological, but I’ll get back to the epistemic and methodological later.

Ontological reductionism is no longer a widely held view in philosophy, for reasons I find hard to comprehend. It seems to be tied up with two issues: functionalism in philosophy of mind, and functionalism in biology. In philosophy of mind one of the starting points arguments spring from is that there are facts about mind, such as “seeing red” or “feeling what it is to be in pain” that just are not reducible to physics (a long debate about “identity theory”, or the claim that the mind is identical to brain states argues that this is not the case, most recent leading examples being Searle’s Chinese Room and Jackson’s Mary Problem). But while the identity theory debate concluded rightly that we cannot identify pain states with neural states, the reason is not because there is something ontologically privileged in the mental realm, but rather because we think something is pain when it satisfies, among other things, social criteria. In short pain is the neurological and the social. This extends, in my view to all psychological and semantic properties. What counts as seeing red is something that obtains when public stimulus response criteria are met, and these are constructed from the overall aggregate behaviours of the society or language group. Put simply, red is what the society says is red, and what the society says is red is what the biology of the members of the society typically respond to. The reason why we can’t reduce red-seeing to physical properties directly is that we have an ontological dangler in the social categories used. But if they, too, are physical objects, then everything reduces, directly, to physical descriptions. The Mind-Brain Identity Theory was too restricted in its scope, that’s all.

If Layer Cake Reductionism is faulty, and given that we would need to include things at both higher and lower levels to reduce any class of properties at an intermediate level to a lower level in this way, it surely is, what alternative is there? I want to suggest something I haven’t seen proposed (but given my ignorance of the field almost certainly has been, and much better than I will do here): Pizza Reductionism. On this account, these “higher level phenomena” are not arrayed in a strict hierarchy. They are artefacts of our cognitive dispositions to recognise and describe them, and they are all physical objects. Words and meanings, states of mind, biological properties, and chemical structures are all physics, and should be directly reducible had we but world enough and time. A diagram:

Pizza Reductionism

Each “level” is in reality a heterogeneous class of contingently grouped observer-relative properties, and each is just physical. If there is a principled way to array these properties it might be in terms of scale relative to observers and the practices of observers. We might need to use neurobiology, biochemistry and sociology in a reduction, or we might find it agreeable and convenient to first reduce one “type” of phenomenon to another not-yet-reduced-to-physics phenomenal description, but ontologically it is not self-standing.

Pizza reductionism has some interesting implications. Consider the notion of supervenience. A supervenient property is one that two different physical systems can have, but two identical physical systems must have. It might be that you and a robot see red in physically different ways (the robot using CCD receptors) , but you and I, being identical (for certain values of “identical”) in the relevant sense see red in the same physical manner, with the right sort of L photopsin containing cone cells in our retinas, etc. That makes “seeing red” a supervenient property. But why do we say that the robot sees red in the first place? Because there is a physical property underlying it (light in the region of 600nM) that we typically call “red” that normal visual systems identify. A robot might in fact see evenly over a spectrum, unlike primates, and so not identify red as a distinct class, but it would still pick up wavelengths around 600nM.

So the physical property is the key. It is what exists independent of the propensities and predilections of the observer systems. How we carve that up at scales above the microphysical is conventional. But the phenomena themselves are clearly real: observers really do see reds, feel pain and use descriptors for classes of physical states. It’s just that these are not the final story, the explanans. And here we return to the methodological and epistemic versions of reduction. Alex Rosenberg (one of the last “club footed” reductionists* still about, and with whom I agree) has argued (1994) that the problem with reductionism is simply computational: we just don’t have sufficient ability to work out the properties we see from first principles; neither the time nor the computational capacity.

Consider how this affects a popular notion: emergence. Emergentism was developed in the 1930s to deal with the concept of evolutionary novelty (see my series on that topic here). It has become a bit of a panacea for everything from physics to theology. Complex systems are emergent, no doubt, but what does that mean? Many emergentists treat emergence as an ontological thesis – something new and irreducible has emerged. I, on the other hand, think it means that we are surprised at something we didn’t expect. Emergence is in effect a measure of our surprisal (a term from information theory). Let’s put this into pseudo-formal English:

An emergent property E is, for an observer O, a property that was U degree of unexpected given a knowledge of the underlying properties P and the underlying laws L, and the cognitive limitations of O.

The limitations C include the storage, computational speed, time available, degree of interest, and other relative properties of the observer O. Unless you are God or Laplace’s Demon, you will have these limitations. But let us consider what makes E Eish. We refer to emergent properties as “properties” and thereby hide all manner of complexity. A property is often stated in philosophical analyses as if it were something to be explained, and that is how I mean it here, but little attention is given in these instances to how we delineate it as a property to begin with. Let’s say E is a phenomenon instead, and call the descriptors that we use to identify it as a phenomenon its properties (which is very much in line with Aristotle’s original meaning of propria: they are predicates, or descriptors, and thus semantic objects and not facts of undescribed reality). The question then becomes why we use those descriptors. Would God use them? After all, any observer with unlimited time, computational power, detail of observation, and knowledge of the laws might not even be inclined to see these things as phenomena, a point often made against Laplace’s Demon. Perhaps, though, this is because the phenomenally of these phenomena is due in part to the constrained nature of the observers.

Any observer system O must abstract and isolate what it issues as a description from what is an indefinitely, if not infinitely, large set of possible observants. Humans and other classifier systems (animals, neural net robots, librarians) must pick out some feature classes as salient and significant. They have to or they could not process anything regularly. So what counts as a phenomenon to O must be a two-place relation, between the available observants and the features that O finds salient and significant. In short, while the phenomenon is real (because none of the observable features that make it a phenomenon are unreal), it is also observer-relative. Laplace’s Demon might not see any such phenomenon.

So biology might not be a separate layer for a deity or demon. That might mean biology has no laws, or if it does those laws will be summaries, aggregates or placeholders for laws at the physical “level”. The so-called emergent properties and entities of biology, psychology and the rest of the supra-physical domains are just phenomena that we, as observers find important. Ontological emergence evaporates, leaving only methodological and epistemological emergence, and that is a measure of our surprise. In short, it tells us at least as much about ourselves as it does the phenomena we register surprise about.

[Update: Reader Ant below asks for a definition of an emergent phenomenon.

An emergent phenomenon ? is a set of properties salient to an observer O selected from the totality of properties ? of the universe of discourse, that is U degree of unexpected given a knowledge of the underlying properties P and the underlying laws L, and the cognitive limitations of O.

For a physicalist, this would read

An emergent phenomenon ? is a set of properties salient to an observer O selected from the totality of properties ? of the universe of discourse, that is U degree of unexpected given a knowledge of the underlying physical properties P and the underlying physical laws L, and the cognitive limitations of O.

The universe of discourse is effectively the world, and the phenomenon is selected from the feature set the observer can cognise in that environment.]

So pizza reductionism is a methodological point: we have to investigate the world in terms of these phenomena, but let us never forget they are the explananda not the explanans, a general point that we should apply in the philosophy of mind, ethics, and other non-physical domains and sciences.

[Added: Owen Flanagan has named the problem of naturalising meaning the “Really Hard Problem“; his solution is that prescriptive ideas are based around eudaimonic properties – which is to say, things that make us flourish. I agree with this, but continue to insist these are purely physical relations. Meaning, and here I mean semantic meaning, is a physical thing. It doesn’t exist on Omicron Persei 8, even if there are organisms there and they communicate symbolically. That would be a different set of physical kinds to those that obtain here. So as I think the Hard Problem is not Hard, I think the Really Hard Problem is not either.]

* A term from Paul Griffiths. I immediately identified myself as one when he said that.

54 thoughts on “Pizza reductionism, emergence and phenomena

      1. Most obviously, reductionism doesn’t work. I am always puzzled when people don’t find that obvious.

        Why not do it the other way around? We could have human perceptual experience at the bottom, then knowledge on top of that (via empiricism), then matter on top of that, as arising out of the knowledge, and then science on top of that.

        Or maybe what we really need is something that is a bit more circular, that connects up either way. But, if it is strict reductionism all the way, that kind of circularity would give us nothing. We would have to be solipsists. So maybe there have to be stages where one can be “explained” in terms of the other, but the “explanations” are necessarily incomplete, though they might well be persuasive.


        1. But, if it is strict reductionism all the way, that kind of circularity would give us nothing. We would have to be solipsists.

          One of the big fears in philosophy, religion, science, and morality seems to be that reductionism reduces (*cough*) everything to a meaningless gloop(tm), and this leads to solipsism or nihilism.

          But I think you can argue that while the most accurate description of reality is meaningless gloop, complex agents, such as ourselves, respond to the meaningless gloop through the partial filters of our senses and generate our own ‘meanings’ from what we dimly perceive as salient.

          It would explain a great deal if the differing views of the meaningless gloop were ‘opinions’ rather than slices of reality. And in the end, being or not being a solipsist (or a nihilist) might just be an opinion.


  1. Mostly agree. But a few quibbles.

    How we carve that up at scales above the physical is conventional.

    It’s conventional in that we (or Laplacian demons) aren’t required to use higher level descriptions to describe the happenings of the world. But there nonetheless are objective ontologically robust facts about higher-level structures, and it is these facts that are captured by the special sciences.

    It is a fact about our physical world that pizzas digest in the stomachs of large apes, but rocks don’t. And there are objective truths about which properties are relevant to facts about digestion, and which are not. (E.g., the masses and charges of all quarks and electrons are the same in pizza and in rocks, so the difference in digestibility doesn’t lie there.)

    So I think we do need an account of weak emergence that is compatible with physicalism — a form of physical emergence — that allows us to understand the ontology of higher-level properties.

    Core point: Structural features are real, ontologically robust features of the physical world. The fact that someone can ignore these structural features doesn’t mean that they’re not there.

    So we will have ontological emergence. It will just be a bit more mundane than strong emergentists (like Broad) supposed. It will be an ontological account of the emergence of structure.


    1. I certainly do not deny that the phenomena are real. What I deny is that this way of carving them up is privileged in the real world. When we recognise structure in the universe correctly, we recognise something real. But it is not necessarily the one that matters, if we could even say some structure matters over others independently of observers. The truths are real truths, but not the only ones.

      So a Laplacean Demon would recognise that structure, but a whole lot more as well, and would not recognise the phenomenon except as one of many ways to carve the world at that scale. They are most certainly there, as is all structure at that scale and below, and above. The Demon wouldn’t think it worthwhile focussing on those facts and not all the others. We have to.

      We are species of a certain scale, with certain interests and limitations and affordances (a term I have only recently become aware of, thanks to Nikolai Alksnis). These are brought about by our evolution and adaptation to aspects of our environment. So we recognise objects we might eat, get eaten by, run into or off, or can use. Things are our Umwelt. They are what we respond to, because it matters to us. They are aspects of the world that we must care about for various reasons.


      1. Again, mostly agree, but . . .

        . . . we recognise something real. But it is not necessarily the one that matters, if we could even say some structure matters over others independently of observers.

        Well, there will be an objective matter about what matters, and what doesn’t, for some process or mechanism.

        My point is that we can make sense of which structures matter in relation other structural features (processes, mechanisms, kinds). These facts are objective and do not depend on any observer.

        Of course, not all observers will be interested in all objectively real features of the world.

        But, again, I take it we mostly agree.


  2. In what way is your view reductional? For the physical viewpoint is also not privileged. It almost looks like you have rephrased the Kantian difference between the phenomenal and the noumenal in contemporary philosophical language. There are phenomenon, and there are (for us useful) views. So the reduction seems not to be directed to physics, but to phenomenon.


    1. I’m no Kant scholar, but as I recall it phenomena in Kant’s view are not real things or data, but are constructed by our observation and reason; they are the appearances only. I don’t think they are just appearances. I think they are real. Moreover, some of these concepts or kind terms – the physical – are both appearances and Dingen an sich. That is, we can observe physical objects that are real, in themselves.

      However, you are quite right that I am reviving the notion of phenomenon here out of the Kantian tradition (it’s a revival when philosophers do it, not merely rephrasing); I am not, however, adopting any kind of transcendental idealism.


      1. “we can observe physical objects that are real, in themselves”
        The question I would have with this is how we know that the observations of the physical phenomenon are in themselves while those of, for example, biology are not? What makes physical phenomenon privileged?


        1. Without that presumption, the Humean meta-parsimonious inference, the entire project of science, indeed of learning, is futile. But as the theist in Hume’s Dialogues notes, we do not act as if learning and knowledge of the physical world were futile. So we act as though the world is physical. That is enough to ground my pizza. But should someone come along and say “I do not think the pizza is nourishing” and choose not to eat anything, cake or pizza, then they are free to starve themselves, epistemically speaking. I cannot make them eat.


  3. I think there’s a lot of confusion here between reduction of one theory by another theory, and reduction of a thing to its parts. The former is akin to one-way translation of one language into another language, the latter akin to making a physical object out of Lego bricks. A physically big thing that is identical to the mereological sum of some physically smaller things is nothing remotely like translation. So the idea that things themselves “belong” to one “level” or another of reality strikes me as extremely murky.


    1. Agreed, Jeremy. In particular, the term emergence seems to be defined as the degree of failure to reduce (translate). I – for one – failed to understand by what pizza connection the emergence is nevertheless reduced (was a long post for a Friday knock off).

      And now to the knock off dinner: “Una pizza Sette Stagioni con fisica nel centro per favore – hmm – che gusto irriducible.” 🙂


        1. Thought you like puns and such.

          But the question was, how do you reduce emergent properties? Your solution seems to be to define them away – they only appear to be emergent because of our ignorance.

          Taking your post as analogy, it has a meaning as emergent property. It can be translated into other lnguages without losing the meaning. But it cannot be reduced to rules of grammar and orthography without doing so. That meaning is not an apparent emergence due to our ignorance of either orthography, semantics, or anything else to do with language.

          Do you mean to say that we are not multilingual or polymathic enough, if something appears ot be emergent?


          1. They aren’t defined away; each emergent property is, if correctly assigned, real enough. What is defined away is the idea that this collection of properties is somehow independent of the observer as a collection. Emergence is just a collection of (real) properties among indefinitely many, possibly infinitely many, collections of real properties. Why we privilege them as phenomena has as much to do with us as it does with the things being observed.

            Language is a nice example. In my view it is just a physical system and process. But we think it is somehow ontologically more than that – that words and signs have some kind of reality beyond the practices and noises and markings made by a certain kind of ape. The reason we think that is because, after all, we are that ape. But the universe doesn’t make much of these noises and movements. They are just another form of energy and mass dancing together.

            So the question when encountering an emergent property is: why do we think this is special? and not: what makes this special in the world apart from us?

            I was complimenting you on chiding me in Italian, by the way. I really do appreciate that. Keep ’em coming.


            1. D’oh – that’s clever! The meaning isn’t an emergent property of the text, then, but of our brains. And therein it probably reduces to neurological processes and – er – are we back at layer cake reductionism again?

              Allora – ho ricedersi sulla ordinazione. Una pizza (a)glio e (neur)olio per favore.


              1. Not quite. The meaning isn’t reducible to our brains. It is the interactions of many brains, the environment in which those brains interact, and the states of those brains based on prior interactions. Note: not “reducible to” those interactions, it just is those interactions. This is a full blown naturalism.


              2. John, hope this lands under your last comment as the reply function for that it does not work. I’d better quote first:

                “Not quite. The meaning isn’t reducible to our brains. It is the interactions of many brains, the environment in which those brains interact, and the states of those brains based on prior interactions. Note: not “reducible to” those interactions, it just is those interactions. This is a full blown naturalism.”

                I fully agree with your full blown naturalism, but wonder whether “reduction(ism)” is a useful term within it. My impression is that you first increase the complexity of the system under study by including the observer. No common-sense ‘reduction’ here. Secondly, the term reduction seems to become synonymous with scientific understanding, where that means an understanding allowing stuff like prediction, modelling, or manipulation.

                Finalmente una pizza naturale senza niente sopra e dopo un espressophy.


              3. If you merely want to quibble about words, Joe, we might as well be doing philosophy… oh, wait. Sure, we can talk about naturalism and physicalism without mentioning reductionism, except that the original meaning in Nagel means to take a theory and description of one kind and reduce its entities and processes to the theory and discussion of another. Which is what we do with any naturalism. Common sense or not, that’s what it means. The subsequent overlays of connotation about “reductive” behaviour, genetic or physical determinism and so on are ancillary issues to the core one: what exists? If we can reduce any other description to physics, then only physics exists (i.e., everything is physical). If one is, as I am, a physicalist, then one has a problem with supposedly irreducible phenomena and I guess my point is that you do have to redescribe things until there are only physical systems (and yes, why wouldn’t a physicalist include observers? We aren’t cartesians after all).

                And there’ll be none of that espressosophy here thankyou very much. Chocosophy only. Infidel.


              4. Just because philosophers are madly in love with -isms…

                I can still personally and idiosyncratially prefer terms like translation, scientific understanding and others not so used and abused as reductionism.

                P.S.: I thought espressophy would go well with chocoholism, Cofimetl with Xocolatl, and help digest heavy pizza-reductionism.


  4. Readers here are probably aware of Nagel’s new book, but for those who are not the title is: Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature Is Almost Certainly False


    1. Different Nagel – Ernest Nagel died in 1985. Thomas Nagel, on the other hand, wrote the book to which you are referring.


  5. I think a lot of opposition to the kind of reductionism you describe, rightly so, comes from our modern experience with abstract languages and Computer Science. In computer science there are models of computing that are -consistent with one another-, for example a higher level language like Ada must be consistent with the capabilities of the underlying machine language, but there is no way to deduce, even given unbounded resources, all the the structure of Ada versus all the other possible high level languages, from the underlying lower level machine code model.

    We are in a similar position to that in terms of all the fields you described. Of course Chemistry must obey all the rules of physics, but there are a lot of rules in our chemical models that we have not shown to be predictable from say QED, yes they are consistent with QED, but I remember reading Feynman writing how he realized that we have very little the other direction.

    Second we have a lot of “higher level models” such as classical physics, where we could switch out the underlying model for a different one and the higher level model would continue working exactly the same, making the same predictions. I would argue that all scientific models are effective models in that sense. So there doesn’t seem to be any real forcing -by logic- from one particular model to a specific other. All the forcing is done by comparing to empirical experiments and consistency across models. Consistency does not implay full deducability and I don’t believe that has ever been shown for any two major models, even Classical physics vs Standard Model. There are lots of parts of classical physics that we have not shown (yet) to be derivable directly from a quantum theory. Areas like turbulence. Of course we take with practical certainty that there is consistency.


    1. a lot of rules in our chemical models that we have not shown to be predictable from say QED, yes they are consistent with QED

      There’s an important difference between saying that chemistry is derivable from the laws of QED and saying that it would be derivable in principle from both the laws and the physical state given in the language of QED.

      When we insist on having both the laws and the state, then there’s no important distinction between consistency and predictability.


  6. Thank you for a thoughtful blog post.I have a question. You wrote:
    Alex Rosenberg (one of the last “club footed” reductionists* still about, and with whom I agree) has argued (1994) that the problem with reductionism is simply computational: we just don’t have sufficient ability to work out the properties we see from first principles; neither the time nor the computational capacity.

    I do not think this an argument for your case for reductionism but is rather only a belief [or even an article of faith :)]. Can you comment on this point.

    BTW: I think a blog post devoted to recent papers on emergence theory would be nice.


    1. See my reply to Jeroen Schreurs above. However, I fail to see what about observing our cognitive and computational limitations is an act of faith. It’s an observation. We are cognitively constrained. We aren’t God, in other words, and have no God’s Eye View. I can’t recall anyone who doubts this.

      So I think the argument that (at the least) emergent properties are due to our inability to make the relevant inferences is solid. The issue is whether there is anything else to them. I think not. The onus that there is, in my view, is on the emergentists.

      I may do something more on emergence, if I ever get the time. I’m very underwhelmed by the pro-emergence views.


      1. I have no doubt that the entire history of life can, in principle, be explained by physics, but at the same time, I very much doubt that such an explanation would be as informative as a theory of evolution. I certainly don’t feel that I have to choose between the two.

        Am I wrong to think of evolution as an emergent phenomenon? Or perhaps it is an epistemic version of emergence, and of no more interest to you than epistemic reductionism, at least for the purposes of this essay?


  7. “An emergent property E is, for an observer O, a property that was U degree of unexpected given a knowledge of the underlying properties P and the underlying laws L, and the cognitive limitations L of O.”

    You have to Ls!

    It’d be nice to see this restated in terms of an emergent phenomenon F (!?).



  8. But that much maligned complexity thingy makes its appearance as we move up towards the special sciences. We have ridiculously unlikely correlations between ion fluxes in neurons of the visual cortex and events on the surface of stars several light years distant. These kind of things won’t commonly appear if we sample randomly from the universe.


    1. The complexity is inherent in a complete physics and specification of the boundary conditions of the world. The choice of complexity to observe as we move into the special (i.e., nonphysical) sciences is up to us. The world is already that complex and much much more.

      This is because we represent the physical in simpler general terms, not because the physical actually is somehow simpler.


      1. I must hand wave a little here (from ignorance), but the Bekenstein bound and the holographic principle have been used to estimate the complexity/informational content of our observable universe at ~1e122 bits. That estimate includes total particle states and all interactions. I am guessing that we could estimate informational densities in the fields of the special sciences and compare them to, for example, what goes on in the sun (to pick a complex looking phenomenon). That is, the complexity is not a choice except in the sense of what we are currently attending to.

        Christoph Adami gives some examples of calculating entropy-based measures on homeobox protein structures and how they correlate with species phylogeny and then moves onto information content of complex brains and how this relates to fitness.


  9. Most helpful post for the philosophical ignorant like myself helps put a range of issues in context. I even managed to read the philosophical experiment bits you discussed!

    “were ‘opinions’ rather than slices of reality”

    I would go for perspective rather than opinion based on my small experience of dealing with religion in which I am somewhat prone to a reductionist position I suppose.

    I have a particular regard for early medieval history can’t ignore the church but the questions I ask are not particularly related to religion more how as an organization it successfully held land in contrast often to the aristocracy and how it dealt with violence.

    Control of environment type questions with a very strong social and biological basis.

    But i can temper my perspective and my inclination to ask specific types of questions that interest me with very different perspectives. I find it particularly interesting to read historians who have religious faith as they bring a very different perspective to the table and insight, some of which I am not going to accept but it often raises issues I would otherwise of not thought of and ignored.

    Diversity and dispute is important to arrive at a balanced perspective. Personally I don’t like labeling my own thought as it is prone to change shape and move the more I read but I can identify with a lot of the statements here on reductionism.


    1. I appreciate the replacement term “perspective”, and as you may recall I have talked before about “perspectivalism”. I just can’t remember when or what I said. I hope it was sensible.


  10. If we need the physical state also along with the models of Physics to derive our models of Chemistry then our models of Chemistry are not derivable from our models of physics, and there is something extra in them that describes the physical state we needed. That extra part is what I would call “emergent” or non-determined from the lower level model. The deductions we are discussing are all in our models, which we use to compare to the world, and I think not visible in the natural world. There is no Chemistry or Physics there, just nature doing its thing.


    1. I’m sorry Markk, but I don’t get your point. Let’s consider the laws of physics in two sets of conditions: immediately after the Big Bang, when everything is subatomic plasma, and on the surface of a nondescript rock 14.5 billion years later. The laws remain constant (we hope!), but the state in which those laws are played out vary wildly. There is no chemistry in the first, but plenty in the latter. So to that extent, sure, we can say chemistry is emergent: it emerges when the conditions, the physical states, permit. But chemistry is then just a phenomenon relative to the description of the physics we prefer for those conditions. There is nothing nonphysical about it. These states, or boundary conditions, specify what the physics is doing there and then. The laws of physics specify how it is done. Ontologically, there is just physics.


  11. If we nipped back a few hundred years, then physics would be the bottom layer of the Chocolate cake and God the cake-stand, with God’s laws underpinning what may or may not happen in a relatively static universe ‘cycling to Newton’s fixed laws of gravity’. – Darwin removed that stable underpinning from biology – Einstein upended God’s stability – so it might seem that physics is now the cake stand.

    The major differences between a past and a present layer-cake picture is that Gods cake-stand was static, whereas, with Einstein’s physics, now the cake-stand is all changing.

    Interestingly in your pizza picture, physics is part of the piece of pizza and the plate the piece of pizza rests on is unnamed. (Do not try to say this twice.) (Does the plate stand on the backs of four elephants standing on a turtle of indiscriminate sex etc.?) (Ignore these asides.)

    What exactly does the cake-stand or the plate represent?

    Then what does the cake-stand stand on, or the plate rest?

    Is it legitimate only to say that, because mathematics can explain physics, especially as we have apparently identified the Higgs boson, then things are as they are because they are and that’s it.

    Is the cake-stand perhaps the expansion of the universe? – How different would things be if the expansion rate was different than it is in this universe.

    Is the cake-stand particle or force or particle/force? – How many particles does the universe contain – is it an odd or even number?

    Can we label the plate under your piece of pizza odd – or should the label read even?

    Assuming that the laws of physics are at the base of our realties – that they determine what may or may not happen – then do those laws demand that the universe is one of change – or is the universe change, then the laws we perceive stem from that situation?

    It strikes me that of the laws, the controls, that we perceive in the various layers of the scientific Chocolate cake, some have yet to cross the time boundary between God as the foundation, rather then physics or physical law.

    With God at the base, there was some purpose, whatever might be a Gods purpose.

    Can there be purpose with physics as the base? – To what might physics or physical law aim – if there could or may be an aim?

    Darwin saw nature’s purpose was to provide variety – the means of change to better suit the environment – so as to achieve some perfecting of form. – This rather than simply to produce change just to meet environment change, which is todays version. – In both versions, evolution is seen as a means to change.

    Our concepts of perception though entail that what we perceive remains relatively stable. – For us to identify something, it must remain stable at least long enough for us to see it and give it a name.

    So somewhere in the scheme of things, in this all changing universe, there must be a provision, a system, a ruling, a process (What might we call it?) aiming to stability. – Otherwise there would be no stabilities for us to identify.

    What is in the makeup of the cake-stand that makes for the stability of the clearly identified layers of the cake? – What is in the makeup of the plate under the pizza giving identity, though slightly less distinct, to the ingredients of the pizza?

    Are there gaps between the layers of the cake that we must leap to cross to different disciplines – are the gaps filled between the ingredients of the pizza.

    Are there gaps between species we identify or are gaps filled?

    Does nature allow leaps across gaps between what we identify. – Does nature saltum naturalis? (Pardon my Latin)


    1. It would be “does nature facit saltum”, I think, in dog Latin.

      There is no cake stand. Or, to put it another way, there is only the cake stand. The pizza is an epiphenomenon. A tasty, tasty epiphenomenon.


  12. Being dyslexic, often when I write, if I read it 24 hrs later it is unintelligible. I might have surpassed myself with the above reply. On the other hand it may have some merit. Being dyslexic it’s hard to know.

    What am I trying to say? – Try this.

    At the beginning – an expansion of plasma or whatever – the universe we know was ‘in a particular set of circumstances’. – We can say the same for its present state. – The universe is now ‘in a particular set of circumstances.’

    We try to account for those circumstances and how we fit in with those circumstances. – How might we describe this situation?

    The nearest analogy I can think of is to be standing on a pavement in front of an empty restaurant, the waiters and chef are standing about doing nothing. I can say, ‘There is a particular set of circumstances.” – I go into the restaurant, the waiters hover, I order my dinner, the chef sets about cooking, more people come in, the wine waiter does his bit, the place is humming and eventually I’m well fed and satisfied ready to move on, bill paid and heading for the door. I can say, “There is a particular set of circumstances.”

    I can put a label on this whole thing – all circumstances involved. – I can call it, ‘Being out for a meal.’

    How might we label all circumstances of the universe – and acknowledge our relationship to them?

    It was easy when no one thought beyond, ‘I am part of God’s plan’. – I can say, ‘I am a fleeting moment in the unfolding of the universe.’ – These are easy cop outs. – They do not tell me the essence that underlies the chocolate layer cake or the pizza.

    Does it matter. – I’ll be damned if I know. – What I do know though is that I am an animal, that has evolved intelligence enough to see the awesomeness of the universe I am part of. – It might be that the ape I am is the only thing in the universe with a mind capable of such vision, able to delve into its mysteries. – It would be a shame if we failed to understand the circumstance of the universe. – Sad if we simply continued to greedily gobble the resources of our planet, whilst fighting religious wars and other such worthy pursuits, till the ape we are becomes extinct. – That may happen sooner than we think. Then it could be that for the rest of eternity, the universe remains unseen.


    1. I don’t know if it helps, but remember the scene in Big Bang Theory where Sheldon is helping Penny do her business manufacturing, and she asks him how he knows this. Sheldon replies: “Penny, I am a physicist. I know about everything.” To which she replies, “Who’s Radiohead?” He has a long twitchy pause, and says he knows everything important about the universe, when in fact he knows only how a universe would behave if it had things in it. What things there are actually about is what matters, the physics only tells you what they would do. Consequently I would say that to understand the world you need to know both the boundary conditions and the Rules.


  13. “To understand the world [universe] we need to understand both the boundary conditions and the rules.”

    [Please treat all of this me checking out my understanding. – I work at a simple level and would love to enroll on your philosophy course for 8 to 10 year olds.]

    A young girl once asked me what colour is it outside infinity. – Knowing that would help a lot – but in the meantime I suppose we must settle for the idea that one boundary of understanding is the moment of the big bang – the dawn of this particular expansion – though the opposite future condition is perhaps forever speculative. – One rule might be that from past to present, all inhabits an expansion.

    We might consider an expanding plasma as one state (boundary condition) of the universe – compare the present state to that – and (as the present is rather more of a certainty than the future) use the present state as the opposite boundary – then, if working between those boundaries we are able to find understanding, we can use that understanding to check out if speculation of future meets the laws we might have found.

    Writing about the conservation of energy, Richard Feynman in The Feynman Lectures on Physics [1964], sums the relationship between science and logic in three sentences:
    “There is a fact – or if you wish, a law, governing all natural phenomena that are known to date. There is no known exception to this law – it is exact so far as we know. The law is called the conservation of energy.”

    It’s all down to what do we know as fact – and there seems few facts compared to vast speculation.

    Fact. – My dog Pugsley has fleas. (I speculate he speaks dog Latin but he generally only says woof – fact is I got 2% in my final Latin exam, so he probably knows more Latin than me.)

    Apparent fact. – There is a gap of sorts between me and Pugsley.

    Fact. – His fleas jump from him to me.

    Apparent fact. – There is a gap of sorts between the docks and nettles in my garden – but it seems a lesser gap than those between me Pugsley and his fleas – because docks and nettles are both weeds. (Weeds are no different to other plants, its just that people don’t like weeds.)

    Fact. – There are gaps, filled with Chocolaty (oooh) cream, between the sponge layers of a Chocolate layer cake.

    Apparent fact. – There seems lesser gaps between the ingredients of a nicely cooked pizza.

    Apparent fact. – There is a gap between the earth and the moon – a gap between our solar system and the next – a gap between our galaxy and the next – and there might be a gap between our universe and the next.

    Fact. – There are no apparent gaps credited in the expanding plasma dawn of this universe. (Though there seems to be flaws in the microwave background.)

    We arrive at a question. – Is there a continuum from the dawn of the universe to the present – or can real gaps have appeared in the continuum?

    Clearly Pugsley’s fleas think there are real gaps – but not insurmountable ones.

    If we consider a smaller set of boundary conditions – the dawn of life to the present we can ask the same question.- Is there a continuum from the dawn of the life to the present – or can real gaps have appeared in the continuum?

    We arrive at the species problem. – The fossil record says life is a layer cake – Darwin’s joined up change says pizza.

    To me, whether we look parochially at life, or consider the whole picture, the problem is one and the same – but unlike most problems, where we can ask is the answer this or that, we are denied any option because, contrary to what a flea might think, the dictum is that nature does not allow leaps – all must somehow be fitted into the continuum idea – regardless of how contrived some of our answers become.

    I like gaps – but the problem with gaps is that they demand boundaries.

    Think of the gap between an elephant and a butterfly. – On face value the gap is a clear as crystal. (And when did you last see an elephant fly?) – But to make that gap we must but a boundary around an elephant and a butterfly – and if we do that we have a serious problem. – We must put a boundary round everything else we identify.

    How do we explain a universe where we put a boundary of nomenclature round all we identify yet at the same time deny anything other than a continuum with no boundaries?

    Is there a real boundary around say a species called Elephant – or a species called physics – or one called philosophy? – Henry Fleeming Jenkins thought there was a boundary round species in life. – I think there is a real boundary round all the we see as existing – all we put names to – but not just one of nomenclature.

    Of course the minute such a boundary exists then to move on – to unfold – there is either a breakdown of that boundary or a leap across it – or a combination of both.

    Darwinian thinking denies both boundaries and leaps – but essentially for only one reason. – It has only one mechanism – of joined-up change. – A second mechanism to facilitate leaps (facit saltums) would be really handy to explain the apparent gaps and their associated boundaries – and stop fleas getting paranoid about the whole business.

    I would like to hear you views on the reality of a boundary round a species like elephant – also your views on how saltums might or may not be facited.


    1. The desire to circumscribe boundaries between things is a feature of our predilections. We are comfortable with boundaries. But the world has few discrete boundaries at any scale, and so we are better off in the light of science and reflection to focus in on the centres of things, not the boundaries. Species are not absolutely separated. The fossil record in no way indicates a layer cake. [Strata are not ontological layers; they are sequences.]

      Do not make the mistake I call the ontological fallacy, of supposing that because we have words for things, the universe is obliged to make things to fit the words.


  14. Is it not that, from plasma at one boundary, the universe has made things we find at the present boundary, and that to satisfy our predilictions, and our hope for understanding, we are obliged to make words to fit the things (a damn good word) we see. Nevertheless our words, quite latecomers in the evolution game, might be inadequate for our pictures. Mine certainly are.

    It just might be possible that I have found a discrete boundary which applies at any scale. May I email details for you to critically stamp on in private as I am not ready to float it publicly?


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