Within physics there are two ways of establishing the relative fundamentality of one theory compared to another, via two senses of reduction: "inter-level" and "intra-level" (Crowther, 2018). The former is standardly recognised as roughly correlating with the chain of ontological dependence (i.e., the phenomena described by theories of macro-physics are typically supposed to be ontologically dependent on the entities/behaviour described by theories of micro-physics), and thus has been of interest to naturalised metaphysics. The latter, though, has not been considered interesting (...) for metaphysics, because it is not thought to correlate either with ontological dependence, nor causal or dynamical dependence. I argue, however, that this is a mistake, and that actually, the intra-level relation does reflect ontological dependence (in the same sense as the inter-level relation) and thus should not be neglected by metaphysics of physics. This argument further supports the assertion that the same notion of fundamentality underlies both the inter- and intra-level claims of fundamentality in physics, and that this notion of relative fundamentality in physics correlates with that of metaphysics. (shrink)

Most philosophers of physics are eliminativists about causation. Following Bertrand Russell’s lead, they think that causation is a folk concept that cannot be rationally reconstructed within a worldview informed by contemporary physics. Against this thesis, I argue that physics contributes to shaping the concept of causation, in two ways. (1) Special Relativity is a physical theory that expresses causal constraints. (2) The physical concept of a conserved quantity can be used in the functional reduction of the notion of causation. The (...) empirical part of this reduction makes the hypothesis that the transference of an amount of a conserved quantity is a necessary and sufficient condition for causation. This hypothesis is defended against several objections from physics: that amounts of energy do not possess the appropriate identity conditions required for being able to be transmitted, that there is no universal principle of the conservation of energy in General Relativity, and that there are at least two types of physical systems in which causation does not involve any transference: entangled systems in quantum mechanics and the Aharonov–Bohm effect. In order to show that physics provides means to elaborate the concept of causation it is important to avoid certain misunderstandings. In particular, the claim that there is causation in a physical world does not mean that causation is an additional ingredient of the “furniture” of the world, over and above the ingredients identified by physics. (shrink)

The thesis proposes, defends, and applies a new model of inter-theoretic reduction, called "Neo-Nagelian" reduction. There are numerous accounts of inter-theoretic reduction in the philosophy of science literature but the most well-known and widely-discussed is the Nagelian one. In the thesis I identify various kinds of problems which the Nagelian model faces. Whilst some of these can be resolved, pressing ones remain. In lieu of the Nagelian model, other models of inter-theoretic reduction have been proposed, chief amongst which are so-called (...) "New Wave" models. I show these to be no more adequate than the original Nagelian model. I propose a new model of inter-theoretic reduction, Neo-Nagelian reduction. This model is structurally similar to the Nagelian one, but differs in substantive ways. In particular I argue that it avoids the problems pertaining to both the Nagelian and New Wave models. Multiple realizability looms large in discussions about reduction: it is claimed that multiply realizable properties frustrate the reduction of one theory to another in various ways. I consider these arguments and show that they do not undermine the Neo-Nagelian of reduction of one theory to another. Finally, I apply the model to statistical mechanics. Statistical mechanics is taken to be a reductionist enterprise: one of the aims of statistical mechanics is to reduce thermodynamics. Without an adequate model of inter-theoretic reduction one cannot assess whether it succeeds; I use the Neo-Nagelian model to critically discuss whether it does. Specifically, I consider two very recent derivations of the Second Law of thermodynamics, one from Boltzmannian classical statistical mechanics and another from quantum statistical mechanics. I argue that they are partially successful, and that each makes for a promising line of future research. (shrink)

We argue against claims that the classical ℏ → 0 limit is “singular” in a way that frustrates an eliminative reduction of classical to quantum physics. We show one precise sense in which quantum mechanics and scaling behavior can be used to recover classical mechanics exactly, without making prior reference to the classical theory. To do so, we use the tools of strict deformation quantization, which provides a rigorous way to capture the ℏ → 0 limit. We then use the (...) tools of category theory to demonstrate one way that this reduction is explanatory: it illustrates a sense in which the structure of quantum mechanics determines that of classical mechanics. (shrink)

The numerous and diverse roles of theory reduction in science have been insufficiently explored in the philosophy literature on reduction. Part of the reason for this has been a lack of attention paid to reduction2 (successional reduction)—although I here argue that this sense of reduction is closer to reduction1 (explanatory reduction) than is commonly recognised, and I use an account of reduction that is neutral between the two. This paper draws attention to the utility—and incredible versatility—of theory reduction. A non-exhaustive (...) list of various applications of reduction in science is presented, some of which are drawn from a particular case-study, being the current search for a new theory of fundamental physics. This case-study is especially interesting because it employs both senses of reduction at once, and because of the huge weight being put on reduction by the different research groups involved; additionally, it presents some unique uses for reduction—revealing, I argue, the fact that reduction can be of specialised and unexpected service in particular scientific cases. The paper makes two other general findings: that the functions of reduction that are typically assumed to characterise the different forms of the relation may instead be understood as secondary consequences of some other roles; and that most of the roles that reduction plays in science can actually also be fulfilled by a weaker relation than (the typical understanding of) reduction. (shrink)

One of the defining features of the classical gene was its position. In molecular genetics, positions are defined instead as nucleotide numbers and there is no clear correspondence with its classical counterpart. However, the classical gene position did not simply disappear with the development of the molecular approach, but survived in the lab associated to different genetic practices. The survival of classical gene position would illustrate Waters’ view about the practical persistence of the genetic approach beyond reductionism and anti-reductionist claims. (...) We show instead that at the level of laboratory practices there are also reductive processes, operating through the rise and fall of different techniques. Molecular markers made the concept of classical gene position practically dispensable, leading us to rethink whether it had any causal role or was just a mere heuristic. (shrink)

Most philosophers of physics are eliminativists about causation. Following Bertrand Russell’s lead, they think that causation is a folk concept that cannot be rationally reconstructed within a worldview informed by contemporary physics. Against this thesis, I argue that physics contributes to shaping the concept of causation, in two ways. 1. Special Relativity is a physical theory that expresses causal constraints. 2. The physical concept of a conserved quantity can be used in the functional reduction of the notion of causation. The (...) empirical part of this reduction makes the hypothesis that the transference of an amount of a conserved quantity is a necessary and sufficient condition for causation. This hypothesis is defended against several objections from physics: that amounts of energy do not possess the appropriate identity conditions required for being able to be transmitted, that there is no universal principle of the conservation of energy in General Relativity, and that there are at least two types of physical systems in which causation does not involve any transference: entangled systems in quantum mechanics and the Aharanov-Bohm effect. In order to show that physics provides means to elaborate the concept of causation it is important to avoid certain misunderstandings. In particular, the claim that there is causation in a physical world does not mean that causation is an additional ingredient of the "furniture" of the world, over and above the ingredients identified by physics. (shrink)

At the beginning of the 20th century, Gestalt psychologists put forward the concept of psychoneural isomorphism, which was meant to replace Fechner’s obscure notion of psychophysical parallelism and provide a heuristics that may facilitate the search for the neural correlates of the mind. However, the concept has generated much confusion in the debate, and today its role is still unclear. In this contribution, I will attempt a little conceptual spadework in clarifying the concept of psychoneural isomorphism, focusing exclusively on conscious (...) visual perceptual experience and its neural correlates. Firstly, I will outline the history of our concept, and its alleged metaphysical and epistemic roles. Then, I will clarify the nature of isomorphism and rule out its metaphysical role. Finally, I will review some epistemic roles of our concept, zooming in on the work of Jean Petitot, and suggest that it does not play a relevant heuristic role. I conclude suggesting that psychoneural isomorphism might be an indicator of robustness for certain mathematical descriptions of perceptual content. (shrink)

This article elaborates local selective realism in view of the shifting from classical to quantum electrodynamics. After some introductory remarks, we critically address what we call global selective realism, hence setting forth the background for outlining local selective realism. When examining the transition from classical to quantum electrodynamics, we evaluate both continuities and discontinuities in observational features, mathematical structures, and ontological presuppositions. Our argument leads us to criticise the narrow understanding of limiting-case strategies, and to reject the claim that we (...) need a fully coherent theoretical framework to account for the transition from one theory to its successor in the case of electrodynamics. We close with a few remarks on the scope of local selective realism. (shrink)

It is the aim of this paper to develop and defend an interpretation of level of scientific discipline within the truth-maker framework. In particular, I exploit the mereological relation of proper parthood, which is integral to truth-maker semantics, in order to provide an account of scientific level.

The numerous and diverse roles of theory reduction in science have been insufficiently explored in the philosophy literature on reduction. Part of the reason for this has been a lack of attention paid to reduction2 (successional reduction)---although I here argue that this sense of reduction is closer to reduction1 (explanatory reduction) than is commonly recognised, and I use an account of reduction that is neutral between the two. This paper draws attention to the utility---and incredible versatility---of theory reduction. A non-exhaustive (...) list of various applications of reduction in science is presented, some of which are drawn from a particular case-study, being the current search for a new theory of fundamental physics. This case-study is especially interesting because it employs both senses of reduction at once, and because of the huge weight being put on reduction by the different research groups involved; additionally, it presents some unique uses for reduction---revealing, I argue, the fact that reduction can be of specialised and unexpected service in particular scientific cases. The paper makes two other general findings: that the functions of reduction that are typically assumed to characterise the different forms of the relation may instead be understood as secondary consequences of some other roles; and that most of the roles that reduction plays in science can actually also be fulfilled by a weaker relation than (the typical understanding of) reduction. (shrink)

In times of crisis, when current theories are revealed as inadequate to task, and new physics is thought to be required—physics turns to re-evaluate its principles, and to seek new ones. This paper explores the various types, and roles of principles that feature in the problem of quantum gravity as a current crisis in physics. I illustrate the diversity of the principles being appealed to, and show that principles serve in a variety of roles in all stages of the crisis, (...) including in motivating the need for a new theory, and defining what this theory should be like. In particular, I consider: the generalised correspondence principle, UV-completion, background independence, and the holographic principle. I also explore how the current crisis fits with Friedman’s view on the roles of principles in revolutionary theory-change, finding that while many key aspects of this view are not represented in quantum gravity, the view could potentially offer a useful diagnostic, and prescriptive strategy. This paper is intended to be relatively non-technical, and to bring some of the philosophical issues from the search for quantum gravity to a more general philosophical audience interested in the roles of principles in scientific theory-change. (shrink)

Relationships between current theories, and relationships between current theories and the sought theory of quantum gravity (QG), play an essential role in motivating the need for QG, aiding the search for QG, and defining what would count as QG. Correspondence is the broad class of inter-theory relationships intended to demonstrate the necessary compatibility of two theories whose domains of validity overlap, in the overlap regions. The variety of roles that correspondence plays in the search for QG are illustrated, using examples (...) from specific QG approaches. Reduction is argued to be a special case of correspondence, and to form part of the definition of QG. Finally, the appropriate account of emergence in the context of QG is presented, and compared to conceptions of emergence in the broader philosophy literature. It is argued that, while emergence is likely to hold between QG and general relativity, emergence is not part of the definition of QG, and nor can it serve usefully in the development and justification of the new theory. (shrink)

We examine some assumptions about the nature of 'levels of reality' in the light of examples drawn from physics. Three central assumptions of the standard view of such levels (for instance, Oppenheim and Putnam 1958) are (i) that levels are populated by entities of varying complexity, (ii) that there is a unique hierarchy of levels, ranging from the very small to the very large, and (iii) that the inhabitants of adjacent levels are related by the parthood relation. Using examples from (...) physics, we argue that it is more natural to view the inhabitants of levels as the behaviors of entities, rather than entities themselves. This suggests an account of reduction between levels, according to which one behavior reduces to another if the two are related by an appropriate limit relation. By considering cases where such inter-level reduction fails, we show that the hierarchy of behaviors differs in several respects from the standard hierarchy of entities. In particular, while on the standard view, lower-level entities are 'micro' parts of higher-level entities, on our view, a system's macro-level behavior can be seen as a ('non-spatial') part of its micro-level behavior. We argue that this second hierarchy is not really in conflict with the standard view and that it better suits examples of explanation in science. (shrink)

Convincing disputes about explanatory reductionism in the philosophy of biology require a clear and precise understanding of what a reductive explanation in biology is. The central aim of this book is to provide such an account by revealing the features that determine the reductive character of a biological explanation. Chapters I-IV provide the ground, on which I can then, in Chapter V, develop my own account of explanatory reduction in biology: Chapter I reveals the meta-philosophical assumptions that underlie my analysis (...) of reduction, Chapter II introduces the previous debate about reduction in the philosophy of biology by pointing out the most crucial lessons one should learn from this debate, Chapter III critically discusses the two perspectives on explanatory reduction that have been proposed in the philosophy of biology so far, and Chapter IV clarifies in what ways the issue of reduction is entangled with the issue of explanation. In Chapter V I present my own account of explanatory reduction. My main claim is that reductive explanations in the biological sciences possess three main characteristics: they explain the behavior of a biological system S, first, exclusively in terms of factors that are located on a lower level of organization than S, second, by focusing on factors that are internal to S , and third, by describing the genuine parts of S only as “parts in isolation”. This account is ontic because it traces the reductivity of an explanation back to certain relations that exist in the world. (shrink)

This dissertation consists of three parts. Part I is a defense of an artificial language methodology in philosophy and a historical and systematic defense of the logical empiricists' application of an artificial language methodology to scientific theories. These defenses provide a justification for the presumptions of a host of criteria of empirical significance, which I analyze, compare, and develop in part II. On the basis of this analysis, in part III I use a variety of criteria to evaluate the scientific (...) status of intelligent design, and further discuss confirmation, reduction, and concept formation. (shrink)

What is the role of bridge laws in inter-theoretic relations? An assumption shared by many views about these relations is that bridge laws enable reductions. In this article, I acknowledge the naturalness of this assumption, but I question it by presenting a context within thermal physics (involving phase transitions) in which the bridge laws, puzzlingly, seem to contribute to blocking the reduction.

I offer an explanation of why inertial and gravitational mass are equal in Newtonian gravitation. I then argue that this is an example of a kind of explanation that is not captured by standard philosophical accounts of scientific explanation. Moreover, this form of explanation is particularly important, at least in physics, because demands for this kind of explanation are used to motivate and shape research into the next generation of physical theories. I suggest that explanations of the sort I describe (...) reveal something important about one way in which physical theories may be related diachronically. (shrink)

The Three Papers comprising this series, together with my earlier [34] also published in this journal, constitute an attempt to set out the major issues in the theoretical domain of reduction and to develop a general theory of theory reduction. The fourth paper, [34], though published separately from this trio, is integral to the presentation and should be read in conjunction with these papers. Even so, the presentation is limited in scope – roughly, to intertheoretic reduction among empirical theories – (...) and informal in presentation – not least because a satisfying formal account of theories has yet to be offered. And despite the length, the treatment is still condensed; often corroborating and/or intuitively helpful detail has had to be consigned to footnotes or omitted. I approach the problem from within my own naturalistic realist philosophy of science and formal analysis of abstract hierarchy in theory. The sources for the former are [25], [29], [31], and [32] and those for the latter essentially [27] and [30]. Hierarchical notions played a significant role in the already published [34]. (shrink)

Holism and reductionism are usually seen as opposite and mutually exclusive approaches to nature. Recently, some have come to see them as complementary rather than mutually exclusive. In this book I have argued that, even stronger, they should be seen as mutually dependent and co-operating research programmes. I have discussed holism and reductionism in biology in general and in ecology in particular. After an introductory chapter I have provided an overview of holistic and reductionistic positions in biology, and of the (...) reduction problems to which they relate. I have argued that it is extremely important to distinguish between ontological, epistemological and methodological aspects of these problems. The overview has shown that there are actually several approaches to reduction problems in biology, which can be characterized as more or less radically or moderately holistic or reductionistic. It has shown also that there are three major ’contradistinctions’ between holism and reductionism in biology, to wit the doctrine of emergence versus the reduction thesis; functional explanations versus causal explanations; and phenomenology versus mechanicism. In later chapters I have shown that these ’contradistinctions’ are not really contradistinctions at all. In the next chapters I have discussed the terms ’reduce’ and ’reduction’ in science. In chapter 3 I have discussed the reduction of laws and theories. I have shown that there are many different types of reduction depending on the auxiliary hypotheses that are being used in addition to the reducing theory: approximation-, aggregation, correlation and/or identification-hypotheses. The distinctions between these types has later, in chapter 5, proved to be of great importance in defining the concept of ’emergence’. The major conclusion of chapter 3 was that reduction is an epistemological issue, pertaining to logical relations between statements or systems of statements. It should not be confused, therefore, with ’ontological reduction’, certainly not in one of its ordinary senses, such as diminishing, devaluating or the like. Scientific reductions are, with the exception of instrumentalistic reductions, kinds of explanation, and, moreover, non-eliminative kinds of explanation. This means that a reduced law or theory is not eliminated by the reducing theory but rather consolidated or even reinforced. The ontology of the reduced law or theory is thereby also being consolidated. In chapter 4 I have argued that the same holds for reductions of concepts. Concept reductions are supposed to be accomplished by means of so-called ontological identity relations, which are in turn supposed to connect terms in the law or theory to be reduced, which do not occur in the reducing theory, with theoretical terms of the reducing theory. Because they are called ontological identity relations, several philosophers have thought that concept reductions imply some form of ontological reduction. And because they often occur in the context of micro-reductions, some have even thought that concept reductions are themselves micro-reductions. As a result, the idea has arisen that ontological identity relations are connections between macro-concepts and micro-concepts. However, concept reductions by means of ontological identity relations cannot be micro-reductions, because micro-reduction is, by definition, reduction with an aggregation step. Moreover, ontological identity relations are relations between different representations of and the same type of thing or attribute. That is, they express different epistemological sides of the same ontological coin. Therefore, concept reductions cannot be considered ontological reductions either, certainly not in the ordinary sense of diminishing, devaluating or the like. Thus, concept reduction is, like law or theory reduction, an epistemological issue: it pertains to relations between, in this case, different concepts or representations of one and the same type of thing or attribute. ’Ontological reduction’, then, may, in the context of scientific reductions, actually be considered a contradiction of terms. In chapter 5 I have linked this conclusion to the emergence thesis and to the alleged contradistinction between this thesis and the reduction thesis. I have shown that the doctrine of emergence actually consists of two separate claims, namely an ontological thesis stating that a whole has emergent properties which the component parts do not possess, neither separately nor in other partial combinations; and an epistemological thesis stating that emergent properties of wholes are ’in principle’ irreducible. I have argued that the first claim may be regarded as a valid, universal thesis about relations between properties of wholes and properties of parts, but that the second claim is untenable. I have discussed many emergent properties of wholes, biological as well as physico-chemical, that have proved to be explainable in terms of micro-theories about the component parts and auxiliary hypotheses. Once again, however, it is important to realize that reduction is an epistemological issue, whereas emergence, in the sense of thesis, is an ontological one. It is not ’wholes’ or ’emergent properties of wholes’ that are being reduced but statements about them. Reduction is a kind of explanation, not of explaining-away. Thus, it leaves the ontology of whatever is reduced fully intact. I have developed a new definition of the term ’emergence’ which expresses emergence in terms of the auxiliary hypotheses that may be used in reductions, in particular aggregation-, correlation- and identification-hypotheses. This has even lead to two very remarkable conclusions. First, emergence may be considered the opposite of ontological identity. And second, if there were no emergence, there wouldn’t be any reductions either. to reduce.) In this respect, therefore, there is absolutely no contradistinction between holism and reductionism. On these grounds I have introduced my thesis that holism and reductionism should rather be seen as mutually dependent, and hence co-operating, research programmes than as conflicting views of nature or of relations between sciences. Holistic programmes play an important role in science as guide programmes for reductionistic programmes by discovering or developing macro-laws or -theories about phenomena at the level of wholes, which they themselves, however, cannot explain. For these explanations they depend on the fruits of reductionistic programmes. If the latter succeed in providing the explanations they act as supply programmes for the holistic guide programmes. Reductionistic programmes depend in turn on holistic programmes for providing the macro-laws or -theories that call for these explanations. In chapter 6 I have discussed an example of this mutual dependency in the form of the reduction of the Bohr-effect in animal physiology. I have shown that this law has been reduced to the theory of allostery, applied to hemoglobin molecules in red blood cells, and that this application of the theory of allostery has been reduced to the theory of chemical bonding. I have also shown that at least six research programmes were involved in these reductions, and that the relations between these programmes can be characterized very well in terms of the model of holistic guide programmes and reductionistic supply programmes. The only, but highly significant, qualification appearing from example was that the terms ’holistic’ and ’reductionistic’ are extremely relative and should always be related to a certain given level of organization. In chapter 7 I have resolved the remaining contradistinction between holism and reductionism in biology, viz. the need for functional explanations and the demand that explanations be causal. I have shown that functional explanations are perfectly legitimate explanations which in a sense can be reconstrued as causal explanations. I have argued that functional explanations are indispensable components of more comprehensive, causal-evolutionary explanations, because the latter appeal to the adaptive value, and hence the function, of the property to be explained. In that sense functions can be regarded as adaptations, and functional explanations can be regarded as a sort of ’short-hand’ for evolutionary explanations. Finally, I have shown that in the context of functional explanations, too, co-operation of holistic and reductionistic research programmes occurs. In part 2 I have applied my thesis to ecology. I have shown that in ecology too, holismreductionism disputes notwithstanding, co-operation of holistic and reductionistic research programmes occurs, or, in so far as this appears to be not the case, that it should be strived after. In chapter 8 I have given an overview of reduction problems in ecology and of the various approaches to these problems. I have noticed that in ecology, too, there are several, radical, moderate and anti-reductionistic research strategies, with respect to the levels of both ecosystems, communities and populations. I have also noticed, however, that concrete solutions to reduction problems in ecology are frustrated by what is called the intellectual immaturity or the anomalous status of ecology. This refers to the almost complete lack of general laws and theories in ecology, at least at the higher levels of communities and ecosystems. Of a number of possible causes I have lifted out two, which lend themselves to philosophical analysis and clarification. The first one is the ambiguity of a major part of the ecological vocabulary. This was the subject of chapters 9 and 10. The second is the inhibitory effect which holism-reductionism disputes have on the growth of knowledge. This was the subject of chapter 13. In chapter 9 I have discussed the concept of an community. It appeared that the term ’community’ is used for several different entities at various levels of organization. This ambiguity alone seems to be sufficient for the lack of ’general’ laws and theories about ’communities’. My purpose in chapter 9 was to try and contribute to a solution of this problem. In doing so I have argued, first, that it seems wise to use the term ’community’ only for groups of species belonging to a single taxonomic or phylogenetic group, and to use the term ’biocoenosis’ for the higher level of organization, defined as the biotic component of an ecosystem. Next I have argued that, although species within communities may of course interact with each other, interaction is itself not a necessary or sufficient condition for community membership. Finally, I have hit upon what is known as the most notorious problem in community ecology, to wit the boundary problem, as well as the problem of heterogeneity. I have found that the cause of these problems lies in the fact that communities are almost invariably being seen as groups of populations occurring together in space and time, whereas the empirical fact is rather that populations of different species mostly do not occur together in the same space, and, moreover, that the species composition of communities changes continuously. This has lead to the suggestion that a community had better be defined as the group of individuals of two or more species occurring in the area of intersection of populations of these species. It is only in such intersection areas that one can really talk of the co-occurrence of species. I have shown the empirical adequacy of this definition by discussing various salt marsh plant communities on the Dutch island of Schiermonnikoog. In chapter 10 I have clarified two other important, yet highly controversial, concepts in ecology, to wit habitat and niche. It appeared that there are at least four different habitat concepts in ecology, and as many niche concepts, the additional complication being that two of these habitat concepts correspond to two of these niche concepts, whence the distinction between habitat and niche is blurred. In addition, different habitat concepts appeared to correspond to different environment concepts and also to different biotope concepts. My purpose in chapter 10 was to disentangle all these concepts from one another and to supply each of them with a suitable term. I have done so by keeping a close eye on commonly accepted notions about habitat differentiation and niche differentiation, two ’principles’ allowing one to explain the coexistence or non-coexistence of species in communities. The results can be found in boxes 5 and 7 in chapter 10. In chapter 11 I was finally able to substantiate my claim that in ecology, too, co-operation of holistic and reductionistic research programmes occurs. I have discussed the reduction of the classical competition model of Lotka and Volterra to modern niche theory. The Lotka/Volterra model is a phenomenological model: it describes the possible effects of competition between two species. Modern niche theory, on the other hand, is a mechanistic theory, in which both the objects of competition and a mechanism are being specified. I have shown that the reduction was established with the help of a relatively simple identification hypothesis and two relatively simple aggregation hypotheses, making it yet another example of heterogeneous microreduction in biology. In the reduction, the Lotka/Volterra model acted as a holistic guide programme and modern niche theory acted as a reductionistic supply programme. In chapter 12 I have discussed another example of co-operation in the form of the approximative reduction of MacArthur and Wilson’s equilibrium theory of island biogeography. I have argued that this can be seen as a holistic model, which has been of great unifying and especially heuristic value, but which in time has been found to be a bit too simple and in some respects had to be corrected. Therefore, it can also be seen as an idealization in the sense of the model of idealization and concretization, which subsequent research programmes have concretized. Because these concretizations have a reductive character, we can see in this structure of idealization and concretization yet another example of the co-operation of holistic and reductionistic research programmes in ecology. A philosophically interesting side-conclusion was that the model of idealization and concretization thus appears to apply also to relations between research programmes, and not only to programme-internal developments. In chapter 13 I have discussed an example of the inhibitory effect that holism-reductionism disputes may have on the growth of knowledge. The example concerns a controversy in island biogeography over the role of interspecific competition in structuring communities. This controversy has lasted for about ten years, appeares to have died out rather than to have been resolved, and has produced nothing new in the field of explanations of community structure. I have shown that the major factors underlying the controversy were differing, in casu holistic and reductionistic, views of communities. Though this presented a problem for my thesis, I have argued that, ultimately, the controversy can be resolved, and in a sense has been resolved, in a way that corroborates my thesis. In the epilogue, finally, I have mentioned some remaining problems concerning the adequacy of the present reduction model in dealing with reduction in ecology. These problems pertain to the question of specificty of ecological laws and theories, the likelihood that reductions in ecology generally occur on the basis of several reducing micro-theories, and the possible relationship between the former two points. (shrink)

In Molecular Models: Philosophical Papers on Molecular Biology, Sahotra Sarkar presents a historical and philosophical analysis of four important themes in philosophy of science that have been influenced by discoveries in molecular biology. These are: reduction, function, information and directed mutation. I argue that there is an important difference between the cases of function and information and the more complex case of scientific reduction. In the former cases it makes sense to taxonomise important variations in scientific and philosophical usage of (...) the terms function and information . However, the variety of usage of reduction across scientific disciplines (and across philosophy of science) makes such taxonomy inappropriate. Sarkar presents reduction as a set of facts about the world that science has discovered, but the facts in question are remarkably disparate; variously semantic, epistemic and ontological. I argue that the more natural conclusion of Sarkar’s analysis is eliminativism about reduction as a scientific concept. (shrink)

Given that scientific realism is based on the assumption that there is a connection between a model's predictive success and its truth, and given the success of multiple incompatible models in scientific practice, the realist has a problem. When the different models can be shown to arise as different approximations to a unified theory, however, one might think the realist to be able to accommodate such cases. I discuss a special class of models and argue that a realist interpretation has (...) to understand these models of a system as ‘ perspectival ’, in close analogy to different spatial perspectives onto the same object. For this sort of case, I also respond to Morrison's recent claim that in the process of unifying models into an overarching theory, explanatory and descriptive power are lost, leaving the unified theory with less of a claim to a realist interpretation than the models themselves. Introduction Perspectival models from singular perturbation problems Unification of perspectives without losses of explanatory power Perspectives as different levels of a system Perspectival models, idealizations and pluralism. (shrink)

This paper addresses a relatively common scientific (as opposed to philosophical) conception of intertheoretic reduction between physical theories. This is the sense of reduction in which one (typically newer and more refined) theory is said to reduce to another (typically older and coarser) theory in the limit as some small parameter tends to zero. Three examples of such reductions are discussed: First, the reduction of Special Relativity (SR) to Newtonian Mechanics (NM) as (v/c)20; second, the reduction of wave optics to (...) geometrical optics as 0; and third, the reduction of Quantum Mechanics (QM) to Classical Mechanics (CM) as0. I argue for the following two claims. First, the case of SR reducing to NM is an instance of a genuine reductive relationship while the latter two cases are not. The reason for this concerns the nature of the limiting relationships between the theory pairs. In the SR/NM case, it is possible to consider SR as a regular perturbation of NM; whereas in the cases of wave and geometrical optics and QM/CM, the perturbation problem is singular. The second claim I wish to support is that as a result of the singular nature of the limits between these theory pairs, it is reasonable to maintain that third theories exist describing the asymptotic limiting domains. In the optics case, such a theory has been called catastrophe optics. In the QM/CM case, it is semiclassical mechanics. Aspects of both theories are discussed in some detail. (shrink)

In this article, we redefine classical notions of theory reduction in such a way that model-theoretic preferential semantics becomes part of a realist depiction of this aspect of science. We offer a model-theoretic reconstruction of science in which theory succession or reduction is often better - or at a finer level of analysis - interpreted as the result of model succession or reduction. This analysis leads to 'defeasible reduction', defined as follows: The conjunction of the assumptions of a reducing theory (...) T with the definitions translating the vocabulary of a reduced theory T' to the vocabulary of T, defeasibly entails the assumptions of reduced T'. This relation of defeasible reduction offers, in the context of additional knowledge becoming available, articulation of a more flexible kind of reduction in theory development than in the classical case. Also, defeasible reduction is shown to solve the problems of entailment that classical homogeneous reduction encounters. Reduction in the defeasible sense is a practical device for studying the processes of science, since it is about highlighting different aspects of the same theory at different times of application, rather than about naive dreams concerning a metaphysical unity of science. (shrink)

Kim’s model of ‘functional reduction’ of properties is shown to fail in a class of cases from physics involving properties at different spatial levels. The diagnosis of this failure leads to a non-reductive account of the relation of micro and macro properties.

Building on previous work, I continue the arguments for scientific realism in the presence of a natural level structure of science. That structure results from a cognitive antireductionism that calls for the retention of mature theories even though they have been "superseded". The level structure is based on "scientific truth" characterized by a theory's validity domain and the confirming empirical data. Reductionism (including fundamentalism) fails cognitively because of qualitative differences in the ontology and semantics of successive theories. This cognitive failure (...) exists in spite of the mathematical success of theory reduction. The claim for scientific realism is strongly based on theory coherence between theories on adjacent levels. Level coherence consists of mathematical relations between levels, as well as of reductive explanations. The latter refers to questions that can be posed (but not answered) on a superseded level, but which can be answered (explained) on the superseding level. In view of the pluralism generated by cognitive antireductionism, theory coherence is claimed to be so compelling that it provides strong epistemic justification for a pluralistic scientific realism. (shrink)

Several philosophers of science have claimed that the correspondence principle can be generalized from quantum physics to all of (particularly physical) science and that in fact it constitutes one of the major heuristical rules for the construction of new theories. In order to evaluate these claims, first the use of the correspondence principle in (the genesis of) quantum mechanics will be examined in detail. It is concluded from this and from other examples in the history of science that the principle (...) should be qualified with respect to its nature and relativized with respect to its scope of application. At the same time this conclusion implies a qualification and a relativization of the heuristic power of the principle. Generally speaking, intertheoretical correspondence is primarily of a formal-mathematical and empirical but not of a conceptual nature. Moreover, it only applies to certain parts of the theories involved. Finally, a number of philosophical justifications of the principle are discussed and some conclusions are drawn concerning the debates on theory reduction and on the discovery-justification distinction. (shrink)

According to Wimsatt, a proper treatment of reduction must distinguish between two types of reductionist activities scientists engage in. One of the benefits of better understanding the nature of reduction, he believes, is that it shows that eliminativism, that is, the elimination of concepts and theories from science, is a rather circumscribed and limited affair, especially in the case of inter-level reductionist activities. While I agree with Wimsatt that it is important to distinguish the two types of reductionisms, I show (...) that elimination in inter-level reductionist activities can be a powerful heuristic in science, driving both inter-level and successional reduction. (shrink)

I analyse Rueger’s application of Kim’s model of functional reduction to the relation between the thermal conductivities of metal bars at macroscopic and atomic scales. 1) I show that it is a misunderstanding to accuse the functional reduction model of not accounting for the fact that there are causal powers at the micro-level which have no equivalent at the macro-level. The model not only allows but requires that the causal powers by virtue of which a functional predicate is defined, are (...) only a subset of the causal powers of the properties filling the functional specification. 2) The fact that the micro-equation does not converge to the macro-equation in general but only under the constraint of a “solvability condition” does not show that reduction is impossible, as Rueger claims, but only that reduction requires inter-level constraints. 3) Rueger tries to analyse inter-level reduction with the conceptual means of intra-level reduction. This threatens the coherence of his analysis, given that it makes no sense to ascribe macroproperties such as thermal conductivity to entities at the atomic level. Ignoring the distinction between theses two senses of “reduction” is especially confusing because they have opposite directions: in intra-level reduction, the more detailed account reduces to the less detailed one, whereas in inter-level reduction, the less detailed theory is reduced to the more detailed one. 4) Finally I criticize Rueger’s way of using Wimsatt’s criteria for emergence in terms of non-aggregativity, to construct a concept of synchronic emergence. It is wrong to require, over and above non-aggregativity, irreducibility as a criterion for emergence. (shrink)

I discuss arguments about the relationship between different “levels” of explanation in the light of examples involving multi-scale analysis. I focus on arguments about causal competition between properties at different levels, such as Jaegwon Kim’s “supervenience argument.” A central feature of Kim’s argument is that higher-level properties can in general be identified with “micro-based” properties. I argue that explanations from multi-scale analysis give examples of explanations that are problematic for accounts such as Kim’s. I argue that these difficulties suggest that (...) some standard assumptions about causal competition need to be revised. (shrink)

The notion of levels has been widely used in discussions of cognitive science, especially in discussions of the relation of connectionism to symbolic modeling of cognition. I argue that many of the notions of levels employed are problematic for this purpose, and develop an alternative notion grounded in the framework of mechanistic explanation. By considering the source of the analogies underlying both symbolic modeling and connectionist modeling, I argue that neither is likely to provide an adequate analysis of processes at (...) the level at which cognitive theories attempt to function: One is drawn from too low a level, the other from too high a level. If there is a distinctly cognitive level, then we still need to determine what are the basic organizational principles at that level. (shrink)

This paper explicates two notions of emergencewhich are based on two ways of distinguishinglevels of properties for dynamical systems.Once the levels are defined, the strategies ofcharacterizing the relation of higher level to lower levelproperties as diachronic and synchronic emergenceare the same. In each case, the higher level properties aresaid to be emergent if they are novel or irreducible with respect to the lower level properties. Novelty andirreducibility are given precise meanings in terms of the effectsthat the change of a bifurcation (...) or perturbation parameterin the system has. (The same strategy can be applied to otherways of separating levels of properties, like themicro/macro distinction.)The notions of emergence developed here are notions of emergencein a weak sense: the higher level emergent properties wecapture are always structural properties (or are realized insuch properties), that is, they are defined in terms of the lowerlevel properties and their relations. Diachronic and synchronicemergent properties are distinctions within thecategory of structural properties. (shrink)

This is a first tentative examination of the possibility of reinstating reduction as a valid candidate for presenting relations between mental and physical properties. Classical Nagelian reduction is undoubtedly contaminated in many ways, but here I investigate the possibility of adapting to problems concerning mental properties an alternative definition for theory reduction in philosophy of science. The definition I offer is formulated with the aid of non-monotonic logic, which I suspect might be a very interesting realm for testing notions concerning (...) localized mental-physical reduction. The reason for this is that non-monotonic reasoning by definition is about appeals made not only to explicit observations, but also to an implicit selection of background knowledge containing heuristic information. The flexibility of this definition and the fact that it is not absolute, i.e. that the relation of reduction may be retracted or allowed to shift without fuss, add at least an interesting alternative factor to current materialist debates. South African Journal of Philosophy Vol. 25(2) 2006: 102-112. (shrink)

A classification of models of reduction into three categories — theory reductionism, explanatory reductionism, and constitutive reductionism — is presented. It is shown that this classification helps clarify the relations between various explications of reduction that have been offered in the past, especially if a distinction is maintained between the various epistemological and ontological issues that arise. A relatively new model of explanatory reduction, one that emphasizes that reduction is the explanation of a whole in terms of its parts is (...) also presented in detail. Finally, the classification is used to clarify the debate over reductionism in molecular biology. It is argued there that while no model from the category of theory reduction might be applicable in that case, models of explanatory reduction might yet capture the structure of the relevant explanations. (shrink)

1. A Historical Look at Unity 2. Field Guide to Modern Concepts of Reduction and Unity 3. Kitcher's Revisionist Account of Unification 4. Critics of Unity 5. Integration Instead of Unity 6. Reduction via Mechanisms 7. Case Studies in Reduction and Unification across the Disciplines.

The doctrine of eliminative materialism holds that belief-desire psychology is massively referentially disconnected. We claim, however, that it is not at all obvious what it means to be referentially (dis)connected. The two major accounts of reference both lead to serious difficulties for eliminativism: it seems that elimination is either impossible or omnipresent. We explore the idea that reference fixation is a much more local, partial, and context-dependent process than was supposed by the classical accounts. This pragmatic view suggests that elimination (...) is not the prime model for understanding the complex relations between the mind and brain sciences, and that we have little ground for concluding that in general psychological kinds do not exist. We suggest that reference changes are better seen as continuous rather than completely eliminative. (shrink)

I begin to develop a framework for emergence in the physical sciences. Namely, I propose to explicate ontological emergence in terms of the notion of ‘novel reference’, and of an account of interpretation as a map from theory to world. I then construe ontological emergence as the “failure of the interpretation to mesh” with an appropriate linkage map between theories. Ontological emergence can obtain between theories that have the same extension but different intensions, and between theories that have both different (...) extensions and intensions. I illustrate the framework in three examples: the emergence of spontaneous magnetisation in a ferromagnet, the emergence of masslessness, and the emergence of space, in specific models of physics. The account explains why ontological emergence is independent of reduction: namely, because emergence is primarily concerned with adequate interpretation, while the sense of reduction that is relevant here is concerned with inter-theoretic relations between uninterpreted theories. (shrink)

The relationship whereby one physical theory encompasses the domain of empirical validity of another is widely known as “reduction.” Elsewhere I have argued that one influential methodology for showing that one physical theory reduces to another, associated with the so-called “Bronstein cube” of theories, rests on an oversimplified and excessively vague characterization of the mathematical relationship between theories that typically underpins reduction. I offer what I claim is a more precise characterization of this relationship, which here is based on a (...) more basic notion of reduction between distinct models of a single physical system. Reduction between two such models, I claim, rests on a particular type of approximation relationship between group actions over the models’ state spaces, characterized by a particular function between the model state spaces and a particular subset of the more encompassing model’s state space. Within this approach, I show formally in what sense and under what conditions reduction is transitive, so that reduction of a model 1 to another model 2 and reduction of model 2 to a third model 3 entails direct reduction of model 1 to model 3. Building on this analysis, I consider cases in which reduction of a model 1 to a model 3 may be effected via distinct intermediate models 2a and 2b, and motivate a set of formal consistency requirements between distinct “reduction paths” having the same models as their “end points”. These constraints are explicitly shown to hold in the reduction of a model of non-relativistic classical mechanics to a model of relativistic quantum mechanics, which may be effected by a composite reduction that proceeds either via a model of non-relativistic quantum mechanics or a model of relativistic classical mechanics. I offer some brief speculations as to whether and how this sort of consistency requirement might serve to constrain the reductions relating other theories and models, including the relationship that the Standard Model and general relativity must bear to any viable unification of these frameworks. (shrink)

Classical accounts of intertheoretic reduction involve two pieces: first, the new terms of the higher-level theory must be definable from the terms of the lower-level theory, and second, the claims of the higher-level theory must be deducible from the lower-level theory along with these definitions. The status of each of these pieces becomes controversial when the alleged reduction involves an infinite limit, as in statistical mechanics. Can one define features of or deduce the behavior of an infinite idealized system from (...) a theory describing only finite systems? In this paper, I change the subject in order to consider the motivations behind the definability and deducibility requirements. The classical accounts of intertheoretic reduction are appealing because when the definability and deducibility requirements are satisfied there is a sense in which the reduced theory is forced upon us by the reducing theory and the reduced theory contains no more information or structure than the reducing theory. I will show that, likewise, there is a precise sense in which in statistical mechanics the properties of infinite limiting systems are forced upon us by the properties of finite systems, and the properties of infinite systems contain no information beyond the properties of finite systems. (shrink)

Currently, there are almost as many conceptions of emergence as authors who address the issue. Most literature on the matter focuses either on discussing, evaluating and comparing particular contributions or accounts of emergence, or on assessing a particular case study. Our aim in this paper is rather different. We here set out to introduce a distinction that has not been sufficiently taken into account in previous discussions on this topic: the distinction between inter-domain emergence—a relation between items belonging to different (...) ontic domains—and intra-domain emergence—a relation between items belonging to a same ontic domain. Our final purpose is not to assume and defend a definite stance on emergence, but to stress the relevance of such distinction when attempting to argue for or against emergence, in the first place. We will also address the connections between emergence so distinguished and more general philosophical perspectives, suggesting where would reductionists and pluralists stand with respect to intra- and inter-domain emergence. (shrink)

Despite the ubiquity of “levels of organization” in the scientific literature, a nascent “levels skepticism” now claims that the concept of levels is an inherently flawed, misleading, or otherwise inadequate notion for understanding how life scientists produce knowledge about the natural world. However, levels skeptics rely on the maligned “layer-cake” account of levels stemming from Oppenheim and Putnam’s defense of the unity of science for their critical commentary. Recourse to layer-cake levels is understandable, as it is arguably the default conception (...) of levels in philosophy. However, relying on this conception of levels undermines the initial plausibility of general dismissals of the concept, because the problems skeptics identify within the “basic idea” of the concept “levels” are merely ones already widely acknowledged in this conception. I illustrate this “guilt by association” by looking at the embedded role of “levels” in articulating intertheoretical reductionism during the latter part of the 20th century. I conclude by suggesting a methodological framework focusing on local usage patterns as a promising means for future analysis of the levels concept. (shrink)

In this article I defend that an underlying framework exists among those interpretations of quantum mechanics which crucially consider the measurement problem as a central obstacle. I characterise that framework as the Received View on the realist interpretation of quantum mechanics. In particular, I analyse the extent to which two of the most relevant attempts at quantum mechanics, namely, many worlds interpretations and Bohmian mechanics, belong within the Received View. However, I claim that scientific realism in itself does not entail (...) commitment to such a view, and I propose to consider a form of realism that dissolves the measurement problem. It is simply a stripped down version of realism. I derive the methodological questions in this form of realism, speculating that within it a novel realist interpretation of quantum mechanics could be conceived. (shrink)

A conventional wisdom about the progress of physics holds that successive theories wholly encompass the domains of their predecessors through a process that is often called reduction. While certain influential accounts of inter-theory reduction in physics take reduction to require a single "global" derivation of one theory's laws from those of another, I show that global reductions are not available in all cases where the conventional wisdom requires reduction to hold. However, I argue that a weaker "local" form of reduction, (...) which defines reduction between theories in terms of a more fundamental notion of reduction between models of a single fixed system, is available in such cases and moreover suffices to uphold the conventional wisdom. To illustrate the sort of fixed-system, inter-model reduction that grounds inter-theoretic reduction on this picture, I specialize to a particular class of cases in which both models are dynamical systems. I show that reduction in these cases is underwritten by a mathematical relationship that follows the broad prescriptions of Nagel/Schaffner reduction, and support this claim with several examples. Moreover, I show that this broadly Nagelian analysis of inter-model reduction encompasses several cases that are sometimes cited as instances of the "physicist's" limit-based notion of reduction. (shrink)

Science depends on judgments of the bearing of evidence on theory. Scientists must judge whether an observation or the result of an experiment supports, disconfirms, or is simply irrelevant to a given hypothesis. Similarly, scientists may judge that, given all the available evidence, a hypothesis ought to be accepted as correct or nearly so, rejected as false, or neither. Occasionally, these evidential judgments can be made on deductive grounds. If an experimental result strictly contradicts a hypothesis, then the truth of (...) the data deductively entails the falsity of the hypothesis. In the great majority of cases, however, the connection between evidence and hypothesis is non-demonstrative, or inductive. In particular, this is so whenever a general hypothesis is inferred to be correct on the basis of the available data, since the truth of the data will not deductively entail the truth of the hypothesis. It always remains possible that the hypothesis is false even though the data are correct. (shrink)

A substantial guide providing an overview of both physicalism and metaphysical naturalism, reviewing both questions of formulation and justification for both doctrines. Includes a diagnostic strategy for understanding talk of naturalism as a metaphysical thesis.