Are There Levels Out There?

levelsby Markus Eronen

Everything in philosophy seems to come in levels. There are levels of organization, levels of abstraction, levels of being, levels of explanation, levels of complexity, levels of analysis… and the list goes on. For example, British emergentists such as Samuel Alexander and C. Lloyd Morgan believed that there are several levels of existence, where phenomena or properties of higher levels emerge from lower ones (life emerges from the chemical level, mind emerges from the biological level, and so on). Nonreductive physicalists such as Jerry Fodor argue that higher-level sciences do not reduce to lower-level sciences, while reductionists want to reduce everything to what they see as the fundamental physical level.

Scientists too like to talk of levels, at least when they are in a philosophical or theoretical mode. Psychologists and cognitive scientists often speak of the behavioral level, the psychological level, the level of the brain, the cellular level, and so on. In evolutionary biology, there is debate concerning the possibility that natural selection happens at various levels: the level of the gene, the level of the cell, the level of the organism, the level of the species, and so on. The protein structure is often described in terms of four levels of organization: amino acid sequences, sub-structures, three-dimensional structures, and the structure of the whole folded protein.

But are there really levels in nature? Do “levels” have a substantial role in scientific theories and explanations, or philosophical analyses?

In this essay, I will argue that the answer to both questions is negative. However, as a first caveat, it should be clear from the above examples that the term “level” can mean very different things in different contexts. Here my aim is to critically analyze just one specific (and important) notion of levels: levels of organization. Although I believe a similar analysis can be applied to other notions of levels, I will not try to argue for it here. As a second caveat, I focus here on levels in the life sciences. I do not believe that the prospects for levels are any better in the physical or social sciences, but that issue is beyond the scope of this essay.

By levels of organization I mean levels that are based on part-whole relations: simply put, there are wholes at higher levels and their parts at lower levels. As an example, consider a human being. One can analyze a human being at various levels of organization: as a part in a social group, as a biological organism, as a complex system composed of cells, at the level of the molecules that make up those cells, at the level of atoms, and finally, at the fundamental level of elementary particles, where a reductionist hopes to find the fundamental explanations, entities, and theories, from which all the rest follows. Thus, we have six levels of organization: social groups, (multicellular) living things, cells, molecules, atoms, and elementary particles. The entities at each level are components of the entities at the next (higher) level.

This rough picture of levels of organization was proposed by Oppenheim and Putnam in their extremely influential paper “The Unity of Science as a Working Hypothesis” [1], and when philosophers and scientists think of levels of organization or the levels of nature, I would guess that they usually have some version or refinement of this picture in mind. There might be large variation in the exact levels and their number, but the basic idea of levels of organization that cut across nature and are based on part-whole relations is both wide-spread and very intuitive.

Unfortunately, it is also thoroughly problematic, as several philosophers have pointed out (see, e.g., [2-3]). The essence of the problem is that nature is too complex for a neat levels-hierarchy: there is a whole range of things that are not easily placed on any level in a simple Oppenheim & Putnam style hierarchy. Consider entities such as organelles, axons, silicon chips, glaciers, books, hurricanes, and so on. Organelles, for example, seem to fit neither on the level of cells (because they are not cells, but rather components of cells) nor on the level of molecules (because they are not molecules). One might add an intermediate level of “organelles” to the hierarchy, but if this is done every time a type of entity does not fit on a level, the result will be hundreds or thousands of levels. The problem is that there is enormous variety and complexity in nature, so if we want to account for everything within one single levels-hierarchy, that hierarchy will not be a neat and appealing layer-cake, but an unintuitive and monstrously complicated construct.

Thus, instead of trying to fit everything into one picture, it is much more plausible to think of levels as local: there may be one set of levels in the retina of a carp, a different set in the pancreas of a human, and yet different levels in the white truffle. This is also the guiding idea of the “levels of mechanisms” approach proposed by Bill Bechtel and Carl Craver [2-5], which is arguably the best account of levels of organization in the literature.

As the title indicates, levels of mechanisms are defined in the context of the “new mechanism” that is popular in contemporary philosophy of science. Levels of mechanisms are based on component-mechanism relations: there are behaving mechanisms at higher levels and their components or working parts at lower levels. That is, at the higher level we have a mechanism that is performing some function, and at the lower level we have the working parts that contribute to the operation of the mechanism. This two-level picture can be expanded into a multilevel hierarchy, when we include the possibility that a working part of a mechanism can be a mechanism itself: the components of that “nested” mechanism then form another level, which is two levels lower than the mechanism as a whole. This process can be iterated as many times as necessary.

Levels of mechanisms are defined only for the mechanism of interest, and do not extend horizontally across nature or even across the whole system under study. For example, there is a certain levels-hierarchy in the human respiratory mechanism, and a different levels-hierarchy in the light transduction mechanism in the retina, and it does not make sense to compare the level of things that are in different mechanisms.

The paradigmatic example given by Craver [2] is the spatial memory mechanism in the hippocampus (of a mouse), where he identifies four levels: the level of spatial memory, the level of spatial map formation, the cellular-electrophysiological level, and the molecular level. In this hierarchy, entities at each lower level are active components in the higher-level mechanism. For example, an NMDA receptor at the molecular level is a component of the LTP mechanism at the cellular level, and the LTP mechanism is in turn a component of the hippocampal mechanism of memory consolidation (at the level of spatial map formation). The hippocampal mechanism of memory consolidation then contributes to the overall mechanism at the level of spatial memory, which is the highest level and includes things such as the mouse performing behavioral tasks (e.g., navigating a water maze).

Bechtel and Craver argue that this local and case-specific approach to levels is sufficient for analyzing issues such as reduction and top-down causation, and that it captures the organization of nature and the talk of levels in science more accurately than alternative (and more global) accounts. I agree that making levels local in this way is a step in the right direction. However, in a closer look, it is questionable whether the levels of mechanisms are levels at all.

According to this account, only things that are in a component-mechanism relation can be at higher or lower levels with respect to one another, and only the (direct or immediate) components of a mechanism are at the same level [2,4]. One implication of this is that entities that belong to two different mechanisms cannot be at the same level, even if they are exactly the same kinds of entities. For example, glutamate receptors in the retinal mechanism of light transduction and the glutamate receptors in the hippocampal mechanism of spatial memory are not at the same level. This might still be palatable, but it gets worse: even two entities of the same kind that are in the same mechanism are often not at the same level. Since only the direct working parts of a mechanism are at the same level, the components of two different submechanisms can no longer be at the same level. For example, if we have two different types of cells in a mechanism, and they both have glutamate receptors, those glutamate receptors are not at the same mechanistic level.

This also implies that there is no single “molecular level” in the spatial memory mechanism, but instead several molecular levels that do not connect into one level. Each type of cell, or perhaps even each component of a cell, has its own molecular level that consists of the molecules that contribute to that sub-mechanism. When we consider a different sub-mechanism (of the same cell or a different cell), that sub-mechanism has a distinct molecular level, and the molecules of each sub-mechanism are not at the same level with respect to each other.

Thus, as an account of levels, the mechanistic approach suffers from a complete lack of generality. In fact, one could argue that the “levels” of Bechtel and Craver are not levels at all, at least not in any interesting sense. They are simply sets of (direct) components of a mechanism. Bechtel and Craver are certainly correct when they point out that it is often very natural and fruitful to analyze complex (biological) systems as mechanisms that have working parts, and often those working parts can be seen as mechanisms themselves that have working parts of their own, and so on. However, why should we think of these compositional hierarchies as “levels”? It is more accurate and unambiguous to describe them simply in terms of components and mechanisms, especially since the term “level” brings along unwanted intuitions, such that there is a single molecular level in the mechanism.

It is often claimed, also by Bechtel and Craver, that levels are “ubiquitous” or “prevalent” in the life sciences [5,6]. However, it is far from clear whether this is actually the case, at least when it comes to research papers. A full-text search in the Journal of Neuroscience shows that the term “cellular level” appears in less than 3.5% of the articles published in the last ten years. The results for terms such as “molecular level” or “level of organization” are even lower. A similar search for Cell reveals a slightly higher result, “molecular level” being the most commonly named level (5-10%, depending on the exact parameters), but this is still far from ubiquitous. Of course, these results are only suggestive, but I think it is fair to say that claims about the ubiquity and importance of levels in science are in need of more evidence and support.

In sum, levels of mechanisms are hardly levels at all, and talk of levels is not at all that common in scientific papers. Is there any hope then for finding a substantial and scientifically relevant sense in which there are levels of organization? I think there remain two approaches that may lead to interesting results. The first of these is based on William Wimsatt’s insightful work on levels (which I cannot discuss here in more detail, see [7] for more). One of his most interesting ideas is that levels can be thought of as local maxima or peaks of regularity and predictability when plotted against a size scale. What this means is that, for example, if there is a “level of molecules,” we should find a peak of regularity and predictability at the size scale of molecules (as opposed to slightly smaller or larger size scales). The main problem with this approach is that it is far from clear how we could measure regularity and predictability [2]. One option would be to evaluate the amount of (causal) explanatory generalizations found at each scale, but that would be a daunting task in itself. In general, although Wimsatt has provided an interesting starting point, until it is developed in more detail, we have to remain agnostic concerning the existence of levels in this sense.

Another possibility would be to understand levels in terms of the typical or paradigmatic entities that occupy a level. For example, it could be argued that there is a cellular-synaptic level in the brain, which includes everything that is or sufficiently resembles a neuron or a synapse. At the molecular level, the paradigmatic entity would be a molecule (perhaps a neurotransmitter), and everything that is or sufficiently resembles a molecule would belong to that level. Similarly, the levels of organization in protein structure could be understood in terms of the paradigmatic structures at each level. Levels in this sense could be local in the sense that they are restricted to the system or organism of interest, and non-exhaustive in the sense that not everything in a system needs to belong to a level. I think this approach might be worth developing in more detail, but it is best seen as heuristically useful, not likely to result in any clear-cut or robust ontology of levels.

This brings me to the next point. Even if it turns out there is no sense in which the term “level” picks out a distinct and natural category, it is unnecessary to ask for levels to be eliminated from science and philosophy. I believe that levels-talk is relatively harmless, and can even be heuristically useful, as long as it is understood to be noncommittal and non-technical, and not intended to refer to any robust or well-defined category. A natural place for this kind of non-technical levels-talk is in introductions and discussions, where levels also most commonly appear in scientific texts. In contexts such as these, the ambiguity and the lack of specific referent for the term makes little difference.

For example, in the classic textbook Principles of Neural Science, Eric Kandel presents the following claim in a section titled “Nerve Cells Differ Most at the Molecular Level”: ”because the nervous system has so many cell types and variations at the molecular level, it is susceptible to more diseases (psychiatric as well as neurological) than any other organ of the body’’ [8]. In this case, the point that Kandel is making is so general that the ambiguity of the expression “molecular level” is harmless. Furthermore, the point can be reformulated without any loss of meaning (in fact, more precisely) in non-level terms: the reformulated statement could be, for example, that the nervous system is susceptible to more diseases than other organs because there is more variation in the molecular composition of nerve cells than in the molecular composition of other kinds of cells.

Similar reasoning applies to philosophy. Consider the common claim (which also Bechtel and Craver make) that we need explanations or theories at several different levels and not just at the physical level. The non-reductive thrust of this general claim comes across regardless of what the exact meaning of ‘levels’ is — the ambiguity (or lack of precise referent) does little harm here. If pressed or if necessary, one can also reformulate or specify the claim without using levels-terminology, for example claiming that we need explanations and theories at various scales, or of various kinds, or throughout compositional hierarchies.

However, in contexts where the term “level” is used in a technical sense and plays a substantial role, it is potentially misleading and harmful. As a case in point, Craver and Bechtel’s [5] account of top-down causation relies on the technical notion of “levels of mechanisms” (which I have discussed above). However, throughout the article Craver and Bechtel slip into thinking of levels in some broader and more intuitive sense, for example in these passages: “There are no causal interactions beyond those at a level” (p. 561), “all of the causal relations are intralevel” (p. 562). Since very few things are at a same level in the technical sense of levels of mechanisms, these claims imply that very few things causally interact, which makes little sense. What Craver and Bechtel really want to say (I think) is that there is no inter-level causation in the sense of causation from a mechanism to the components of that same mechanism, or vice versa. This would have been much clearer if they had simply talked of mechanistic composition instead of levels (see [9] for a more in-depth analysis of this issue).

I believe that this point applies quite generally: for the sake of clarity and in order to avoid misleading intuitions, it is better to avoid “levels” and to use more specific and well-defined terms whenever anything of importance turns on the exact meaning of the term. As I have argued elsewhere [10], in many situations (such as discussions of top-down causation) it is better to replace levels with either scales or compositional relations. Probably the most important scales in the life sciences are the size scale (how big or small objects are) and the time scale (the rate at which processes occur). What I mean by scale here is simply the idea that we measure a certain property (such as size or rate) and then arrange things on a continuum of that property. Thus, for example, big things are higher on the size scale than small things. In contrast to levels, scales are relatively unproblematic. Regarding composition, I believe that the analysis of mechanistic composition (mechanisms and their direct components) provided by Bechtel and Craver is useful, once we get rid of the term “levels” and the sort of intuitions it brings along. Further notions that one can use to analyze the organization of biological systems include control variables, collective variables, sufficient parameters, and aggregativity, to name just a few.

In conclusion, talk of levels should be taken to be noncommittal or heuristic. As a technical term, “level” is problematic and potentially harmful, so it is better to avoid it and look for alternatives: there are no levels out there.


Markus Eronen is a FWO Postdoctoral fellow at KU Leuven (Belgium). His dissertation, at the University of Osnabrück (Germany) focused on “Reduction in Philosophy of Mind:A Pluralistic Account.” His most recent paper is “Robustness and Reality,” published in Synthese.

[1] Oppenheim, P., & Putnam, H. (1958). Unity of science as a working hypothesis. Minnesota Studies in the Philosophy of Science 2, 3-36.

[2] Craver, C. F. (2007). Explaining the Brain. Oxford: Oxford University Press.

[3] Kim, J. (2002). The Layered Model: Metaphysical Considerations. Philosophical Explorations 5, 2-20.

[4] Bechtel, W. (2008). Mental Mechanisms. Philosophical Perspectives on Cognitive Neuroscience. London: Routledge.

[5] Craver, C. F. & Bechtel, W. (2007). Top-down Causation Without Top-down Causes. Biology & Philosophy 20, 715-734.

[6] Kaplan, D. M. (forthcoming). Explanation and Levels in Cognitive Neuroscience. In J. Clausen, N. Levy (eds.) Handbook of Neuroethics. Dordrecht: Springer.

[7] Wimsatt, W. C. (1994/2007). The ontology of complex systems: levels of organization, perspectives, and causal thickets. In W. C. Wimsatt (2007) Re-Engineering Philosophy for Limited Beings. Piecewise Approximations to Reality. Cambridge, MA: Harvard University Press, 193-240. Originally published in Canadian Journal of Philosophy S20, 207-274.

[8] Kandel, E. R., Schwartz, J. H., & Jessell, T. (2000). Principles of neural science, 4th edition. New York: McGraw-Hill.

[9] Eronen, M. I. (2013). No Levels, No Problems: Downward Causation in Neuroscience. Philosophy of Science 80, 1042-1052.

[10] Eronen, M. I. (2015). Levels of Organization: A Deflationary Account. Biology & Philosophy 30(1), 39-58.

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39 replies

  1. Interesting slant on level, if you look at Meme theory and the levels of complexity it does give an insight into how people use their awareness of level, excellent article


  2. Scientific theories are models. Models are intended simplifications, as are levels. I’d contend, without levels there would be little science, other than nuclear physics. One simple example, Neuroscience. Due to the “neuron doctrine”, the field is subdivided into cellular neuroscience and systems (integrative) neuroscience. This division is extremely important for progress in the field, including work on the interaction between these levels. If we throw out “levels” then abstract concepts such as “cells” (or neurons) don’t exist as working models for science.

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  3. Levels are categories invented by humans in the courseof trying to understand the world about us. They are more or less useful depending upon the current state of knowledge, cultural attitudes, and the sophistication of their user. The value of levels is in the construction of useful, simplified models of some portion of our world. The concept of “emergence” ,meaning that another, perhaps simpler, level can be found, This again has to do with our differing ways of viewing phenomena. The world and our views of the world are not the same.

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  4. I found this most interesting, but thought there was a disjunct between your early examples, eg levels of selection, where the concept is pretty central to the scientific disputes, and your later nihilism about its utility in, say molecular biology. It seems reasonable to me that the same neuron type or molecule will function at a different level depending on where it sits within an organisation. When looking at levels of explanation, it is possible that algorithmic measures might be useful – that is, choosing the appropriate size of entity means the description length is minimized. For a behaviour, averaged activity of a population of neurons may be more useful (hey, a sufficient statistic 😉 ) than finer scale information. I am happy to use the term level then – I think a higher level of abstraction makes sense . But more generally, domain might be a less hierarchical term. Anyway, just 2c…

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  5. So “level” is a useful mapping device. The problem seems to be a tendency to attach more significance than is warranted to these conceptual tools. In fact, there are significant areas of physics which seem overly attached to their mapping devices, as somehow more real than that which is being mapped. What say we have this conversation about “dimensions?”

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  6. So “level” is a useful mapping device. The problem seems to be a tendency to attach more significance than is warranted to these conceptual tools. In fact, there are significant areas of physics which seem overly attached to their mapping devices, as somehow more real than that which is being mapped. What say we have this conversation about “dimensions?”

    I agree completely, brodix. The map is not the territory, and I’m not sure why we should abandon the language of ‘levels’ just because it breaks down when reduced. I can understand why this sort of language might not be useful in a room full of specialists, but when dealing with the other 99.9% of the world it still can retain a lot of value. As long as we properly contextualise the language, what’s the problem?

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  7. Thanks for an interesting article. I wonder if it is more the case of asking whether we can say anything at all about “out there” that is not a statement about the best possible scientific model we have.

    These models are the most precise things we can say about reality and It seems to me that whenever we try to go beyond the models we are not saying something that the models do not, we are just saying something less precise and accurate about them.

    For example when Sean Carroll talks about three models of time he is really saying the same thing three times in slightly different words, ie the distinction is semantic. He is talking as though we had some sort of “God’s eye view” of reality.

    So, with levels – all we know of what is ‘out there”, so to speak, is in the models.

    But I think that we can talk of levels if there is a functional distinction to be made. For example when we are talking about a program running on a computer we can talk about how the high level process – the particular program running – and the low level events – the electronic device on which it is running relate in that small differences in the microscopic events (ie voltage fluctuations within the trigger range) do not lead to large differences in the higher level event – ie it is a process that is not sensitively dependent on the microscopic events which instantiate it.

    There might be other kinds of processes where small deviations in the microscopic events lead to large deviations in the high level processes.

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  8. Given that (according to the OP) phrases containing the word ‘level(s)’ are infrequent in the technical scientific literature but more frequent in general, informal discussions or introductory material (presumably as a convenient shorthand), the scientific research community seems not to have a problem with the ‘levels’ concept. So where is (or who has) a problem here? And what exactly is the problem which they (whoever they are) might have?

    Nobody really believes that ‘levels’ have some kind of substantive existence, do they? It is just a convenient (albeit no doubt at times misleading) way of talking.

    Ordinary empirically-minded people (I would suggest) are normally fully aware that the detail of the physical world is too complex to grasp or articulate and also that our words and concepts are often vague or flexible and context-dependent.

    Philosophers, however, at least since the time of Plato have had an unfortunate tendency to hypostasize concepts, to imagine that ‘something lies behind the word’. (To be fair, philosophers are not the only culprits here.) And other philosophers have regularly come along and pointed this out. Think of deflationary accounts of truth, for example (e.g. Paul Horwich’s work).

    With concepts like truth, people outside of the philosophical community sometimes take an interest — they may believe that the truth is ‘out there’ in some sense. They might even be kind of attached to the notion. But ‘levels’??

    So it seems that the problem (if there is one) might lie solely with philosophers of science (and popularizers of their views) who put too much weight on the ‘levels’ concept in their attempt to articulate a preferred reductionist or (usually) anti-reductionist conception of the scientific enterprise.

    It’s a rationalist thing, isn’t it? Imagining that our thoughts are adequate to (or reflections of) reality rather than just being more or less convenient models or metaphors. (Others here have already made a similar point.)

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  9. Yes Markus Eronen, I suspect that the potential to take these humanly fabricated levels as “real,” does happen to be a valid epistemic danger, and thus philosophers and scientists should be wary of them. In the comments above I see general agreement that levels aren’t “real,” but much less acknowledgement that they’re tainting our understandings in general.

    This “levels” issue reminds me of one of my own pet peeves: When I tell others that there are no “true” definitions, or that our various concocted representations are indeed this, they not only tend to agree, but sometimes tell me “Everyone knows that!” The problem however is that I rarely see others actually practicing what I preach. Observe that the default question in the academy seems to be “What is…” time, space, life, consciousness, and so on. This implies that we seek “truth” for such terms, when we should instead be looking for definitions which are “useful” regarding their associated discussions. Rather than challenge a person’s “consciousness” definition, for example, we’d accepted it as given, and then go on to see if anything valuable seems to have been presented by means of it. Furthermore an entirely different “consciousness” definition might be quite valuable as well through a separate argument.

    Getting back to your point, it seems quite reasonable to me that a career scientist (especially when locked inside an “Ivory Tower”!) might tend to consider “epistemic levels” instead as “ontological levels,” or actual reality. Observe Jim Baggott’s wonderful “The Evidence Crisis,” which is given as a chapter from Massimo’s new ebook ( Apparently some physicists will simply never reach the ground once more, though hopefully we’re having fun with their non verifiable ideas anyway. Who doesn’t like reading good fiction?

    I was very happy that Jim used Einstein as an example of an ontologist who nevertheless knew how important it was to check ideas against real world measurement. I believe that many modern physicists have become somewhat blind through their epistemology however, and that this has placed a great stain on Einstein’s amazing career.

    Observe that Heisenberg’s Uncertainty Principal has been tremendously well verified, though Einstein wasn’t confident enough to use this verification to presume that existence itself must then be ontologically uncertain. The reason, I believe, is because this would be the one theorized instance in which effects would occur with absolutely no cause, or essentially as “magic.” So while most modern physicists are proud enough of their epistemology to say, “Existence must be uncertain in an ultimate sense,” Einstein had the integrity to refuse. Though I don’t know if he will ever be vindicated truly, I do mean to help it become known that he (unlike his opposition) did not effectively believe in “magic.”


  10. Many thanks for all the interesting comments!

    First of all, I agree with Robin Herbert and some other commentators that all we have is representations and models and that we can never directly access what is really “out there” (in a deeply metaphysical sense). However, some models, representations, and concepts are better than others, and we can be fairly confident that, for example, tectonic plate models describe some real features of the world. It is quite natural to think that tectonic plates are “out there”. For the reasons mentioned in the article, it is doubtful whether level-concepts pick out any real features in this way.

    However, in spite of this, ‘levels’ can be useful in scientific discourse in various ways, especially in contexts where precision is not crucial, or they can act as placeholders for more precise terms, which is something I am trying to spell out in more detail in a my current research. Thus, I am certainly not advocating abandoning levels-talk completely.

    Mark English asks who has a problem here, and suggests that the answer may be that it is only philosophers of science who put too much weight on the levels concept. To some extent I agree. However, I would include also philosophers of mind, metaphysicians, and also scientists when they are in a philosophical mode and take levels (too) seriously.

    One reason why I came to be critical towards levels is that I tried to look for substantial uses of ‘levels’ in scientific literature (mainly in neuroscience), and found very little. However, more recently I have come across some contexts in science where levels do seem to play some role, and that could benefit from a more detailed (critical) analysis. One prominent example is the levels of selection debate (mentioned also by davidlduffy), where I think some kind deflationary analysis would be appropriate. So although the issue primarily concerns philosophers, there may be useful implications for scientists as well.


  11. Markus Eronen: “…there are no levels out there.”

    I kind of agree. It’s our models of reality that have levels, not reality itself. We model reality at several levels of abstraction because it’s useful to do so. That said, there are things about reality that make it useful to model reality at various levels. For example, atoms combine together in ways that make it useful to treat the combinations as entities in themselves, i.e. as molecules. If atoms didn’t combine, there’d be no use for a molecular level of abstraction. So our inclination to model reality at a certain level does reflect something about the nature of reality. I guess that means there’s a limited sense in which levels are out there, but I wouldn’t say that too loudly, as it might give the wrong idea.

    @Mark English. I think you’ve put it well.


  12. P.S. Markus, it seems to me that you’ve jumped from the conclusion that “level” cannot be made a precise concept to two further conclusions which I don’t think follow:

    1. There are no levels in nature.
    2. “Levels” can have no “substantial role in scientific theories and explanations, or philosophical analyses”.

    Many of our real-world concepts are rather fuzzy, and can’t be given precise definitions, but that doesn’t lead us to say that the things in question don’t exist in nature. “Forest” is rather a fuzzy concept. There’s no formula that specifies the minimum number of trees that constitute a forest, or allows us to demarcate its precise boundary. But I doubt you want to say that forests don’t exist in nature. And while many scientific theories (especially in physics) employ highly precise concepts, the softer sciences often employ rather more fuzzy concepts. As for philosophy, I would say that it mostly deals in fuzzy concepts, and that attempts to provide precise “philosophical analyses” are mostly misguided.

    The distinction between something existing in reality or only in our models of reality is itself a very fuzzy and unclear distinction, and one we need to be very carefully with (or perhaps avoid altogether).

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  13. Hi Markus Eronen,

    As others have said, this seems to attempt to over-analyse and over-formalise what “levels” are.

    It is quite natural to think that tectonic plates are “out there”. For the reasons mentioned in the article, it is doubtful whether level-concepts pick out any real features in this way.

    Nature certainly exhibits “clumpiness” that is real and which can be sensibly described using “levels”. Nucleons go around in nuclei; atoms go around in molecules; and animals are made up of cells. Further, “animals ”, “species” and “ecosystems” are clearly real features of nature, as are planets and stars. All of these are real features “picked out” by “level concepts”.

    But levels will indeed be local and appropriate to the circumstance. We’d use different levels when describing animals than when describing inanimate rocks. The fact that we shouldn’t over-formalise “levels” doesn’t mean that there is anything wrong with the concept itself.

    but it gets worse: even two entities of the same kind that are in the same mechanism are often not at the same level.

    Is there anything wrong with that?

    Thus, as an account of levels, the mechanistic approach suffers from a complete lack of generality.


    I tried to look for substantial uses of `levels’ in scientific literature (mainly in neuroscience), and found very little.

    I’d suggest that’s because most scientific literature is very specific and would use more specific labels. Molecules and cells are both “levels” but in biochemistry you’d tend to use the terms “molecule” and “cell”. The concept of levels is there, but isn’t usually explicit unless the account “goes meta”.

    I think that your article comes to very sensible conclusions about “levels”, but only by rejecting ideas that weren’t sensible in the first place.


  14. richardwein,

    “But I doubt you want to say that forests don’t exist in nature.”

    I see no difficulty in saying that forests don’t exist in nature.

    We walk among these tall, rough-shelled things with irregular poles sticking out of them, all covered with thin green things. We’ve come to call these things ‘trees,’ with their ‘branches’ growing ‘leaves.’ To the extent we can differentiate a large number of these ‘trees’ from areas without much of them, or any of them, we have come to call the area with the ‘trees’ a ‘forest,’ so we have a location in space to which to refer for the sake of directions.

    There are a number of ways we’ve developed to address these phenomena, including careful dissection and analyses of activities and events that permit the objects under study continued existence. But do ‘forests’ exist? Do even ‘trees’ exist except within the discourse of humans needing to refer to ‘those things there’? I confess I doubt this.

    What we call tomatoes are fruit, and watermelons are vegetables – until we get to the table; then it is neither wrong nor nonsense to toss the tomato into the vegetable salad, and afterwards, enjoy the fruity flavor of the watermelon.

    Individuals cannot define words arbitrarily. But the meaning of words is found in their usage, not in the existence of objects to which they are used to refer. That gives us some collective power over how we can or should use words. So distinctions between words and their references are very important.

    Do levels exist ‘in reality?’ I’m not sure I even understand that as a legitimate question (although Eronen’s essay certainly helps clarify the usage of the term).

    Philip Thrift,

    Thanks for the links; rhizomatic theory certainly comes close to my own way of thinking (and fits fairly comfortably with semiotics).

    Liked by 1 person

  15. “I see no difficulty in saying that forests don’t exist in nature.”

    I think there is an underlaying theme from the scientistic debate, in that it seems scientifically assumed that something is not “real,” if it can’t defined and measured to levels of absolute precision, but what if nature is in fact largely “fuzzy” and it is our desire for certitude that is the delusion?

    For example, we find digital devices more effective than analog ones, for very practical reasons, but it seems there is a belief that reality is digital down the Planck level, which would seem illogical, as it would require a “level” smaller than Planck scale to differentiate, i.e. draw the line, between such units. It seems more likely that reality is an articulated continuity, with distinctions that are fuzzy at some scales and points of view and clear from others.

    It seems that what we really need to accept is that there is no such think as an objective point of view. Yes, we can examine details down to the most minute level and find ever more features, but given the uncertainty principle, the act of our observation is both extracting and to some extent, creating that detail. For instance, is a photon truly a point particle prior to its absorption by a light sensor? Might the fact of its uncertainty be due to it being a more diffuse quantum of energy and the atomic structure of the sensor served to absorb it at one point?

    On the macro scale, does a moving car have an exact location? If we were to reduce our observation down to the point no motion could happen, in order to measure an exact location, wouldn’t that also stop the atomic activity of which it is comprised and the car would effectively cease to exist as a car?

    As I suggested there are other concepts, such as dimensions, that we take much more seriously, but which might not hold up under similar questioning. For instance, space is described as three dimensional, but isn’t that really based on the xyz coordinate system and as such is just such a modeling/mapping device for the ultimate territory of space, not some metaphysical foundation for it. We refer generally to these three dimensions, but if they are not specified, as in which are the specific lines, planes, then isn’t it just a fuzzy concept? Yet if we do specify the specific coordinates, then couldn’t other systems equally apply to the same space? For instance, often opposing peoples, such as Israelis and Palestinians, apply different maps to the same space. Usually backed by competing narratives, i.e. time dimensions.

    Yet it seems likely such questions are not going to be raised, because these issues are currently foundational to our sense of certainty.

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  16. Hi Mark,

    So where is (or who has) a problem here? And what exactly is the problem which they (whoever they are) might have?

    I am not sure if this is what he has in mind, but I think that it is a real problem when a way of looking at something is taken as a fact about nature. For example the gene-centric view of evolution may be useful for looking at evolution a different way and seeing things that were not obvious from other viewpoints.

    But when it becomes spoken of as a “truth” as a fact about reality with all its clunky metaphors and reifying of abstract patterns then it is distorting.

    There are other ways of looking at evolution, standing back and looking at the system as a whole, in which these patterns are only a part, and viewing it from a purely technical level.

    I would suggest it also gives a free kick to the creationists because when someone states that a gene, or DNA makes copies of itself, they can simply point out that this is not the case.


  17. Indeed, I am waiting for someone to say that genes have created gene splicing technology and computers in order to copy themselves onto hard drives and from there copy themselves onto new organisms.

    Liked by 1 person

  18. From my go-to man for levels, Bunge [2010] defines ontological and epistemic levels:

    To uniquely characterize the notion of a level of reality we also need that of relation between two adjoining levels. We stipulate that level Ln – 1 precedes level Ln if every object in Ln is composed of objects in Ln – 1. Thus, the part-whole relation defines the level precedence relation.
    The concept of a level allows us to refine that of emergence, namely thus. Instead of saying that property P is an emergent, we should say that P emerges on level Ln, which suggests that P was not possessed by any entities on the preceding level Ln – 1. For example, presumably the property of being valuable emerged along with the life level; and that of acting purposefully emerged along with the level composed of animals endowed with a prefrontal cortex,­ roughly mammals and birds [Huh, what about chemotaxis?].
    The levels examined [above] are ontic, not epistemic: their constituents are material things, not ideas. The epistemic counterpart of the ontic ladder is shown… Whereas the ontic levels are ordered by the ontic relation of precedence, the epistemic levels are ordered by the relation of reducibility, as when physicists explain magnets in terms of the spin and the associated magnetism of their constituent atoms, and social scientists claim that all social facts emerge from individual actions.

    Classical and quantum phenomena have a (minor) levels relationship in this schema. So (from Google Scholar) “physics in a wide range of regimes both at the classical and at the quantum level”, “relevant differences are brought out already at the classical level”, “thorough investigation of 1 + 1 gravity on the classical and quantum level”, “spatial correlation at the quantum level”, “renormalisable at the quantum level” are used. I guess decoherence might count as emergence of novel properties of level n entities by interaction of Ln-1 entities.

    Bunge’s schema kind of hangs together, but I think has problems with how it interacts with logical and mathematical (eg geometric) relations between objects, which are universal across different levels. Also, his dependence of ontology on scientific knowledge implies that we might remove distinctions between levels as understanding changes. He also gives many examples of downward causation eg purposeful behaviour leads to maintenance of hydration of an organism. In his ontology, the value of hydration to the organism, and caring about hydration, exist at a different level of organisation.

    So would this really alter scientific models? A lot of science is limited to one level at a time, so levels talks won’t appear in Cell, but might well in Behavioral and Brain Sciences.


  19. I disagree with the essay. I would say the levels are physics, chemistry, biology, and psychology. You have a range of subatomic particles and fields in physics, as a foundation for a range of atoms as chemistry, as a foundation for a range of cells as biology, as a foundation for a range of neural networks as psychology.

    Psychology is the top level from which we view all levels, but we should respect those levels and how they are foundations for each other when we use psychology to look at nature. Psychology is prone to all sorts or errors, free ranging at the top level, but those errors can be avoided by respecting each level for its contribution to making that top level and its “mind”.

    So, I disagree and say instead that it is better to be mindful of where you got your mind, and how each level contributes to it, as the human mind will be put under increasing stress in future to get things right. There will not be much margin for error in future due to scarcity and destruction.



    Ok, so in reading this very good essay, you are all saying that levels are still convenient ways to communicate between scientists but not the ultimate description of reality. For religions there are levels and hierarchies with God at the top of the divine hierarchy above all of the angels and a hierarchy of clergy in the church on earth. Of course governments have hierarchies and even the three equal branches have Presidents, Legislative Leaders and Supreme Justices. For language and conceptualization the brain is a social organ that communicates at all levels with other brains in the hierarchical matrix. Don’t call the professor a bad name if you expect to do well in his course.

    The miracle of nature is how brains not only see levels but how they make us exist at this level. Just like any engineering system it is not a question of communicating words but actually understanding functions and how functions integrate up the ladder of simple complexities to higher complexities ‘levels’.

    Not really a tough problem to see anymore but still a tough problem to solve if we don’t understand the order and complexity of how the brain and nervous system integrates functions or even what the most fundamental functions actually are. A lot of the neuroscientific pieces ‘theories’ and data are already there, just a question of how to make them all functionally fir together. Comes down to a fairly straightforward bioengineering systems problem.


  21. Hi ejwinner,

    I see no difficulty in saying that forests don’t exist in nature.

    If our concept of “existence” did not include forests as existing then the concept would be rather at odds with all normal usage of the word.

    Yes, a forest is a fuzzily defined composite object, but then so are most things that we see around us which, by common usage, “exist”.

    Do “levels” exist? Not in the same way that forests do. A “level” is not an object, but is instead a descriptive concept about objects.

    Liked by 1 person

  22. Genes have created [biological forms that can make] gene splicing technology and computers in order to copy themselves onto hard drives and from there copy themselves onto new organisms.

    Liked by 1 person

  23. Rhizomes have been mentioned as a useful infiltration of levels-talk. A development of this Deleuzism would be Latour’s actor-network theory which detects (or pursues) a quasi or incipient consciousness in the ‘behavior’ of objects, in the sense that they communicate with us processually, the possibility of which is erased by levels-talk with its static logical hierarchy.

    Joe Public, my principal worry with your defense of levels-talk is that useful, effective and habitual as it is, levels-talk already greases the skids toward the grim future you foresee. The progression from sub-atomic physics to psychology reiterates the (onto)theological Great Chain of Being, and allows us to disavow any direct connection between, say, the Large Hadron Collider and the arms industry. I wouldn’t be surprised if we sometimes evade paradox and contradiction by jumping levels.

    The more comfortable we become in a cyberworld, the less we need to think of reality as being always constrained by a brick-and-mortar pyramid model.

    Thank you, Mark English, for bringing Paul Horwich to my attention. Deflationism is very attractive. His 3 A.M. interview contains this heartening assertion:

    “…you can perfectly well hold that this or that phenomenon is part of the spatio-temporal causal nexus (i.e. is naturalistic) without being a naturalist in general, that is, without holding that everything that exists is naturalistic. I am, as you say, a naturalist about meaning (because it seems clear that our words’ meaning what they do have causes and effects), and my development of Wittgenstein’s equation of meaning with use is supposed to vindicate that position. But I’m not a global naturalist because I think there are perfectly real things (such as numbers and sets and moral properties) that don’t enter into causal relations.”

    Liked by 1 person

  24. Do “levels” exist? Not in the same way that forests do. A “level” is not an object, but is instead a descriptive concept about objects.

    Hi Coel,

    As you noted before you got to your last sentence, a forest is not an object either — it’s a descriptive concept about objects (i.e. trees, animals, moss, etc.). And each of these is a descriptive concept about objects (organisms, organs, cells, etc.), and the rabbit hole goes very deep.

    I think you are right to speak of types or modes of existence, but if we are both materialists, the rabbit hole always ends up at some theoretical base level.

    So the difference between ‘level’ and ‘forest’ isn’t really a substantial difference at all. I don’t doubt that a level is not an object, but surely you must see that a forest (or a tree, or whatever!) is also not an object.

    Liked by 1 person

  25. I think that this proves the old adage that all philosophical discussions boil down to a discussion about what the meaning of “is” is.

    There are no forests in nature in the sense that there are no heaps in nature. But it would make any sort of communication impossible if I couldn’t say that forests exist in nature and people did not know what I meant.

    Also, in a manner of speaking genes created computers in order to copy themselves onto hard drives and eventually copy themselves onto new organisms, but that only underlines that when we say “gene” in this sense we are talking of an abstract pattern and this manner of speaking reifies abstract patterns.

    Usually we don’t attribute causal power to abstract patterns, but as Carnap says we can say a number exists as long as we make it clear we are using this stipulation. In the same way we can stipulate that abstract patterns have causal power and talk on this basis. But then we have to also say that all abstract patterns have causal power and so pi has causal power and the grumpy cat has causal power.

    Then we could say that algorithms created genes in order to create humans who could build computers who could create the internet and grumpy cat memes in order to make lots of copies of algorithms.

    We could say that certainty creates defensive structures in the brain against nuance in order to survive.

    Thinking that way might lead us to all sorts of interesting and even useful insights, just as imagining a demon monkeying with low level physics does.

    But if we forget that such things are just a manner of speaking and start to think that they are statements about the “thing in itself” then I think that we go wrong. In general I think that Mach was right in saying that the “thing in itself” is a superfluous concept, but our minds can’t easily let it go.

    Liked by 2 people

  26. Following this manner of speaking we can note that genes, having created sequencing technology in order to copy themselves onto hard disks in order to survive the extinction of their previous survival machine, do not need to wait to perfect cloning technology in order to copy themselves back into the organic world, because they now have a better, more reliable survival machine at their disposal. Thylocene genes do not need the thylocene any more. Now they can copy themselves onto backup media each day and also copy themselves to the hard disks and backup devices of universities all over the world.

    But, at some stage, torturing this metaphor stops being useful, stops even being fun.

    Here is the downside. Talking in this way, the myth of The Replicator, so to speak says that in the prebiotic world a first Replicator had to arise, that is to say that something that is able to make copies of itself had to arise. The intelligent design crowd and (and do) leap on this and say that this is not only fantastically improbable, it is too fantastically improbable ever to have happened.

    Put that way, they are quite right.

    But if we step back and look at it as a system and take an unemotional technical perspective of what is happening, we can see that there is no need for something to arise that can make copies of itself, that was just the manner of speaking, that was just reifying an abstract pattern and attributing agency to it..

    All that needs to happen is that a pattern among the molecules gets copied for some reason. That is not so improbable. For this to happen in just the way for evolution to get started is rather more improbable, but not too improbable to have happened.

    That does not make the scientific mystery of the start of life any easier, but it does avoid casting it in popular perception as something quite out of the question.

    Time to turn the Necker Cube another way. I can see no reason for the myth of the Replicator to have such a central place in the exposition of biology other than that it appealed to a sort of naive hairy-chested reductionism that was fashionable for a while and is still fashionable in some quarters. Abstract patterns do not have agency, do not struggle, do not make copies of themselves, they are not past masters of the art of survival, they are not our rationale and we are not their survival machines. It is not a “truth” that should fill us with astonishment, it is only a manner of speaking.

    I think that it is not so much of a stretch to say that much of the inspiration and impetus behind the intelligent design movement is the relentless and usually pointless use of intelligent design metaphors by mainstream biologists.

    If you disagree with me then clearly this manner of speaking has created defensive structures in your brain 🙂

    Liked by 2 people

  27. Robin (and Markus)

    A follow-up question I had in mind involved asking Markus to spell out a little bit what implications he thinks his suggested approach might have for one or two particular controversies (like the one you mention, but also perhaps on mind and brain or scientific reductionism generally). I mean, even if it is convincingly argued that there is no substantive point to be settled in relation to specific debates (because the ‘levels’ notion was getting in the way of a perspicuous understanding of the processes in question), it will still be the case — will it not? — that the advocates of certain positions will have had rather more invested in the ‘levels’ concept than others.


    I have a high regard for Horwich and agree with much of what he says, but I must admit that naturalism is my default position. One the things on my ‘to do’ list is to have a close look at his arguments about morality and against naturalism. (I have the same problem with Wittgenstein, but in his case I know something about the religious background which (I think) motivates his ideas on morality.)


  28. Coel wrote: “I think that [the OP] comes to very sensible conclusions about “levels”, but only by rejecting ideas that weren’t sensible in the first place.”

    Isn’t this what philosophy is all about? It wouldn’t exist (or need to exist) if we were not prone to extravagant errors of a certain (i.e. a philosophical) kind.

    This view is, I think, consistent with the way Nietzsche operated. He was one of the first to see clearly that the grammar of a language carries implicit metaphysical baggage.

    And it is also consistent, I think, with the meta-philosophy — and also with intellectual itinerary — of Ludwig Wittgenstein. His later philosophy can be seen as a product of his gradual realization of the problems with his earlier understanding of language (as he slowly worked his way to something approximating to a ‘sensible’ view of language, one which was alert to — and resisted — those ever-present metaphysical tendencies).

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  29. It seems to me that in order for Markus’ project to really do much, various beliefs or practices in science and/or philosophy would need to be found in which levels are taken as “real.” In my opinion the most prominent of them concerns standard treatment of “definition.” If you go to Wikipedia and look up various metaphysical terms such as “life” (, I think you’ll find that researchers generally seek “truth” rather than just “usefulness” with them. What could be more “levelistic” than taking our idiot human terms, as true reality itself?

    For example, instead of permitting a given researcher to either include or exclude viruses under the heading “life” (and thus present his/her associated models as intended), my perception is that papers which are perceived as “definitionally erroneous,” must also be flawed in this manner. If scientists/philosophers today are not yet free to define their terms however they see fit, or essentially “to hone their tools as their work demands,” then this should be a major structural impediment to overcome.

    Robin Herbert, your comment above came just in time.

    I think that this proves the old adage that all philosophical discussions boil down to a discussion about what the meaning of “is” is.

    That’s just it! I’d like to effectively ban the term “is” from our definitions. Here we wouldn’t say “What is…[whatever],” but rather “What’s a useful definition for…[whatever]”.

    I’ll also weigh in on the running “forest” debate, and must begin with Descartes. All that an existing entity can know with certainty is that “it thinks” (assuming of course that it does) — its forest perceptions and such need not address anything “real.” EJ might have been referring to this. Then secondly if one does nevertheless take as given that forest perceptions do reflect reality in some such manner, observe that “forest” will still be nothing more than a term that can be defined any way at all. We generally find this useful as “a group of trees,” and regardless whether or not any such things exist.

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  30. Hi Markus, I thought your essay was a nice read and useful as a reminder to keep an eye on my language. As well as being a molecular/stem cell neurobiologist, I am also an emergentist. So I have definitely used “molecular level”, “cellular level”, etc in discussions (even in lab). But reviewing my own use of such terms I would agree that it is as a general conceptual device without advanced descriptive/scientific value. One has to “fill in” those levels at some point, and habitual use of those terms regardless of context can lead to sloppy writing and thinking.

    That said I had a few disagreements, I think stemming largely from the fact that I seem to have a different vision of what levels are. You seem to describe a hierarchical system, with an almost value laden quality (this higher than that). I guess I would call those tiers. My own concept has always been of either levels of magnification (zooming in and out), or at most levels within a system of concentric rings (so most central to outer). Here are some issues…

    1) That there might end up being thousands or millions of layers if we look into details is not an argument that they are not the case, or “true”. It certainly makes it less practical but nature does not have to be easy for us. Particle physics is a good example. Even if there were millions of subatomic particles with different behaviors we had to account for, well then there is more work for the physicists and not an argument to dismiss the model. Bioinformatics is in a sense trying to detail different levels and that can get very complex.

    2) That some levels don’t seem to be able to lie above or below another does not seem problematic. With the zoom/in out, or concentric rings (where two entities may make up the same ring side by side, and not touch/effect parts of an outer or inner ring) ideas of levels this problem would not seem to crop up.

    3) You seem to suggest that “higher” levels cannot or do not effect lower ones. I think that might be true for some of the core (or lowest) levels, but at this point I’d say ecosystems and societies can work back to effect individual organisms, and minds can work, via the brain and body, to effect things at the cellular, molecular, and perhaps subatomic scales.

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  31. Hi Robin I really enjoyed your posts regarding gene-centric view points. I liked Dawkins’s book Extended Phenotype, and even if not perfect from a molecular biology standpoint, it had some interesting ways of thinking which could be useful in some contexts. The problem is many people, including Dawkins himself at times, seem to have forgotten his genes as agents metaphor was based itself on a Necker cube analogy and that everyone is free to pop the cube back. Sometimes they really should.

    I sort of wish Dawkins would challenge himself by doing that very thing. It might be useful for his fans.

    Hi ejwinner, if forests don’t exist then organisms such as humans don’t exist. The latter are longterm formations of individual cells which themselves may only exist for very short periods of time (compared to the organism) and so can be treated with respect to the behavior of those holistic formations regardless of individual cells. Forests are not merely trees but a collection of different organisms that include trees, where we can treat them with respect to the behavior of that holistic formation (in ecology/ecosystems analysis), regardless of individual units. Your view on forests would seem analogous to mites crawling on your body wondering what this idea of “people” is, all they see are parts and never the coordinated activity of the whole.

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  32. Hi yaryaryar,

    … but surely you must see that a forest (or a tree, or whatever!) is also not an object.

    Well, a plank of wood is certainly an object, and a tree is an “object” as I see it (OED: “A material thing that can be seen and touched”). Unless we re-write the language, composite-objects count as objects. [Indeed, the only non-composite objects are things like excitations of quantum fields, which are among the least object-like things around!]

    I would not call a forest an “object”, nor a biosphere, but, stepping up another level, I would call a planet an “object”.

    I don’t think we should over-analyse or over-formalise terms such as “object”. We would not be arguing about how the world is, only about how we talk about it.

    Planks of wood, trees, forests, biospheres and planets all clearly “exist” in any even-remotely-sensible usage of the term “exists”.

    As for a “level” existing, you could argue it either way (again, the issue is only about how we talk). The patterns and features of reality, that we describe using the term, are certainly real. But I’d prefer to regard the concept of a “level” as descriptive.

    Hi Robin,

    Usually we don’t attribute causal power to abstract patterns, …

    Agreed. We attribute causal power to instantiated patterns.

    … something that is able to make copies of itself had to arise. … [that is] too fantastically improbable ever to have happened. … All that needs to happen is that a pattern among the molecules gets copied for some reason. That is not so improbable.

    There is no difference between those two. If you are envisaging a distinction then it is you who is misunderstanding the “myth of The Replicator”.

    Abstract patterns do not have agency, do not struggle, do not make copies of themselves, …

    But instantiated patterns indeed do.

    Hi dbholmes,

    I sort of wish Dawkins would challenge himself by doing that very thing. It might be useful for his fans.

    Dawkins does take pains in his books to translate his metaphors “into respectable language” (his phrase). I don’t think his fans are at all confused over such things, only his non-fans. 😉


  33. Mark English,

    I think the context where the implications of this are the clearest is the downward causation debate that I also mention in the essay. If we accept that there are no levels in the sense of well-defined layers or strata, then the question of downward causation across ‘levels’ kind of fades away, or can be transformed to more specific questions, such as: Can there be causation from parts to wholes, or vice versa? Can there be causation from large to small scales, or vice versa? The former type of ‘downward causation’ is quite problematic, while the latter (e.g., big things causally influencing smaller things) seems to be quite unproblematic.

    I also think that the issue of reductionism vs. pluralism in general becomes clearer if it is approached in terms of scale and composition, and not in the framework of levels. For example, instead of thinking that there are emergent and irreducible higher levels or higher-level phenomena, I think it is more plausible to think that some phenomena only appear (or can be studied) at certain scales, and may be in some sense irreducible or emergent. Consider weather phenomena such as oscillations or storm systems: They are phenomena that appear at a very large scale, and analyzing them at the scale of molecules or particles would be practically impossible. However, this does not mean that there is a “level of weather phenomena” in the sense of any well-defined layer. The framework of scales brings along a kind continuity that makes it more suitable for analyzing our complex world than the discrete notion of levels.


    I do not think that the fuzziness or imprecision of concepts is the issue here. I am not arguing that the levels concept is fuzzy, but rather that all the extant notions or accounts of levels are incoherent or oversimplify the complexity of nature. The only exception is the “levels of mechanisms” account of Bechtel and Craver, but that is just giving a different name to relations of composition (the whole is a higher “level”, and its parts form a lower “level”). Perhaps there are some further notions of levels that play a substantial and useful role in scientific theories or philosophical analyses, but I have not come across them.
    Since do not think that fuzziness is the issue here, I also do not think that the forest analogy is very relevant. But for what it’s worth, I do think that forests are real!


    Thank you for the interesting remarks on your use of levels, that seems to be entirely in line with the heuristic and non-ontological use that I advocated in my essay!

    (1) If there turn out to be thousands or millions of layers in the world, doesn’t it start to look like there are no discrete layers, but rather continuous scales? If so, then it seems more appropriate to think in terms of scales than levels.
    (2) The “zooming in” or concentric rings approach sounds very interesting and probably I am sympathetic to that, is there any place where I could read more about it?
    (3) I am only skeptical towards downward causation in the sense of a whole affecting its own parts, but besides that I do not think there are any in principle problems of higher-“levels” affecting lower ones, such as mental states causing the body to move around.


  34. Hi Coel,

    I don’t think we should over-analyse or over-formalise terms such as “object”. We would not be arguing about how the world is, only about how we talk about it.

    But is this not what we do in all circumstances? When we come up with labels, we highlight certain things and we hide others — but we never describe what *is*. In the strictest sense, what *is* is matter/energy and everything else is our particular embodied interpretation of it. So I very much agree that all of this is a matter of language, but where I drop off from sharing your analysis is when you start to try to ontologically differentiate between what is ‘real’ and what is not real.

    As far as I see it, it’s all real as our brains are ‘minding’ the sensory data that our bodies create (and obviously, as materialists, this is what we think our brains are doing 100% of the time!).

    In short, I just can’t justify how ‘patterns’ and ‘features of reality’ (and yes, even ‘humans’) are somehow not ontologically different from ‘levels’. At the end of the day, all of this is reflective of how we conceptualize and interpret and talk about the world around us — it’s not reflective of what or how the world *is* in any sense of the term.


  35. Markus,

    I think one way to approach this is to consider the difference between defining and explaining something. In that to define something, we tend to distill out what might be considered its “essential” features, while to explain it, we need to place it in some larger context, that give it the qualities it has.
    For instance, is the mind reducible to images in the brain, or does one place it in a much larger context of perception and feedback, in order to explain it?
    As to levels, the question I would ask is whether you are trying to define what a level is, or whether you are trying to explain how it functions?
    If we were to try to define “level,” it would seem to evaporate as a meaningful concept, because it exists as an intermediate function.
    For example, what is the relationship between forests and trees? Is it in terms of levels, or are there more useful tools to describe the relationship? To compare it to people, the forest is the community and as such, it is the ecosystem in which the organisms of individuals exist. The members of the community are constantly being born and dying, which amounts to a dynamic process for the community of shedding older generations, as it moves onto new ones, so the community moves onto the future, as its members fall into the past.
    So this relationship functions as a dichotomy, rather than levels. Now if you take it up one level on the scale, communities do exist as individual units within a larger network, while taking it down one level and individuals do serve as the ecosystem for communities of microbes.
    So a level does seem to be descriptively valid, but it is a question of taking it in context, or defining it out of existence.


  36. Hi yaryaryar,

    But is this not what we do in all circumstances?

    As as scientific realist I’d say that there is a real world out there, that our language is about. Thus terms such as “atom”, “species” and “planet” refer to real features of the world. Given what our words mean (how they relate to sense data, and hence the external world), statements such as “molecules are combinations of atoms” and “species evolve with time” are about external reality and how it is.

    In contrast, if we take the term “object” and ask “is a tree an object?”, it’s not that we have some prior well-defined concept about the real world, and are then asking whether a tree fits that category. All we’re doing is deciding when we’ll use the term; essentially we are just agreeing what our concept “object” means. This is a matter of how humans use language, but is not really about the nature of the tree.

    Afterall, we’re all agreed what the tree is. People (scientific realists, anyhow!) who disagree about whether a tree is an “object” would not be disagreeing at all about the nature of the tree or what it in fact is, they’d just be disagreeing about how we use the word “object”. In that sense the issue is less interesting.

    The term “level” is a bit different. It refers to real patterns in nature, just as words such as “larger”, or “diffuse” or “smooth” do, and also just as the terms “mountain”, or “sharp object” or “ball” do. Whether you want to use “level” as more of an adjective or more as a noun is really just a matter of taste. Again, the difference there is not about how external things are, it’s about how we use language.


  37. dbholmes,

    The universe as large as it is, and our place in it rather minor and localized, we are indeed something like mites in relation to it. However, unlike your mites, we do not try to understand ideas about the larger whole, but *generate* those ideas, in order to facilitate our living in and with it. However, these ideas being generated by us, are not coming out of the whole, but out of us; they do not exhaust the entities they address, and I merely go a bit further to suggest that there is a limitation to the correlation between our ideas and those entities. No one denies that the entities our words and ideas refer to exist, the question is whether such reference is so exhaustively correlated to the entities’ existence that it effectively encapsulates the necessary existence and properties of those entities (what the ancients knew as ‘essence,’ a metaphysical ontology of being per se). I suggest that this is not the case; and I find it odd for such a metaphysical claim to resurface surreptitiously as a kind of ‘common sense’ faith in the adequacy of (scientific) language.

    Odd, but understandable. Of course our use of language requires a faith in its power to encompass and disclose the reality in which we live. Yet I am suggesting that this is really a function of the usage, uses, and usefulness of language. Language does not encompass anything but our own thoughts, and discloses nothing but the our capacity to respond to the world in which we live and which we share with others.

    BTW, I checked out the Wiki article on “forest.” It opens with a brief discussion of accepted scientific understandings of the term, with some reference to the uses made for it in global policy-making. Then it makes this amusing admission:

    “Although forest is a term of common parlance, there is no universally recognized precise definition, with more than 800 definitions of forest used around the world. Although a forest is usually defined by the presence of trees, under many definitions an area completely lacking trees may still be considered a forest if it grew trees in the past, will grow trees in the future,or was legally designated as a forest regardless of vegetation type.”

    So, which “forest are we discussing here? With or without trees? The ‘that thing, over there’ entity? or the system that we’ve conceived and impose on our maps?


  38. Hi Markus, yes I forgot to add that I liked your idea of using scales or composition, and scales seems very close to my “zooming in/out” idea. I guess that answers the first point.

    2) Uhm… I guess I’ll have to write more so you can read about it! Seriously though, I got to thinking about reductionism/emergence quite a while ago and as far as I know came up with the zooming in/out and concentric circles idea myself. It was just an intuitive thing, because when I thought what makes up X, then I think of zooming in with a microscope, or going up and down geological strata (where a layer need not extend over the whole). I suppose it is possible I read some similar concepts and forgot? If so apologies to whoever. If you’d like me to expand on my idea I like this sort of thing and don’t mind sharing.

    3) For a whole effecting its own parts, would genetic engineering count?

    Hi Coel just to be clear I meant Dawkins should try to explicitly pop the Necker cube back so he is not looking at genes and discuss the world that way. I’ve seen too many fans discuss genes as replicators as if that was the only reality available/worthy of discussion. One could argue Dawkins’s whole career had been dedicated to the other side of the Necker cube since he was an ethologist. But it doesn’t seem to get much airtime or energy anymore.

    Hi ejwinner, I hope it was clear that I wasn’t trying to argue some hard ontological stance/definition, just to challenge the idea forests absolutely do not exist. I’m onboard with some levels of fuzzy and context dependence, so don’t find too much a of a problem with variations in definitions. 800 definitions of forests does seem a bit much, but when caveated with “around the world” it makes sense.

    For ecology I don’t think “legally designated” counts, but yes on forests with or without trees. Just remember the “without trees” in that case is indicating a temporary state.


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