Reduction

Recent discussions of emergence in physics have focussed on the use of limiting relations, and often particularly on singular or asymptotic limits. We discuss a putative example of emergence that does not fit into this narrative: the case of phonons. These quasi-particles have some claim to be emergent, not least because the way in which they relate to the underlying crystal is almost precisely analogous to the way in which quantum particles relate to the underlying quantum field theory. But there (...) is no need to take a limit when moving from a crystal lattice based description to the phonon description. Not only does this demonstrate that we can have emergence without limits, but also provides a way of understanding cases that do involve limits. (shrink)

Paul Humphreys’ main aim in this wide-ranging and ambitious book is to defend a novel account of ontological emergence he refers to as transformational emergence. His secondary aims are many: to show how ontological emergence so understood can be usefully seen against the backdrop of a reductionist position he calls generative atomism ; to compare and contrast his preferred position with historical and contemporary alternatives; and to consider a range of scientific cases both as potential examples of ontological emergence and (...) of weaker forms of emergence stemming from our computational or conceptual limitations. Humphreys is clear from the outset that the range of scientific cases that satisfy certain positive criteria for emergence is too diverse for a single, unified account, and he is more concerned to highlight the differences that preclude such an account than to abstract away from them. The result is a mosaic of case studies, to which are applied a range of alternative conceptions of emergence, drawing out various similarities and differences between the cases, and assessing their credentials as emergent according to the various alternative conceptions considered. (shrink)

Various claims regarding intertheoretic reduction, weak and strong notions of emergence, and explanatory fictions have been made in the context of first-order thermodynamic phase transitions. By appealing to John Norton’s recent distinction between approximation and idealization, I argue that the case study of anyons and fractional statistics, which has received little attention in the philosophy of science literature, is more hospitable to such claims. In doing so, I also identify three novel roles that explanatory fictions fulfill in science. Furthermore, I (...) scrutinize the claim that anyons, as they are ostensibly manifested in the fractional quantum Hall effect, are emergent entities and urge caution. Consequently, it is suggested that a particular notion of strong emergence signals the need for the development of novel physical–mathematical research programs. (shrink)

An elementary algebra identifies conceptual and corresponding applicational limitations in John Kemeny and Paul Oppenheim’s (K-O) 1956 model of theoretical reduction in the sciences. The K-O model was once widely accepted, at least in spirit, but seems afterward to have been discredited, or in any event superceeded. Today, the K-O reduction model is seldom mentioned, except to clarify when a reduction in the Kemeny-Oppenheim sense is not intended. The present essay takes a fresh look at the basic mathematics of K-O (...) comparative vocabulary theoretical term reductions, from historical and philosophical standpoints, as a contribution to the history of the philosophy of science. The K-O theoretical reduction model qualifies a theory replacement as a successful reduction when preconditions of explanatory adequacy and comparable systematicization are met, and there occur fewer numbers of theoretical terms identified as replicable syntax types in the most economical statement of a theory’s putative propositional truths, as compared with the theoretical term count for the theory it replaces. The challenge to the historical model developed here, to help explain its scope and limitations, involves the potential for equivocal theoretical meanings of multiple theoretical term tokens of the same syntactical type. (shrink)

Because biologization of psychiatric constructs does not involve derivation of laws, or reduce the number of entities involved, the traditional term of ‘reduction’ should be replaced. This paper describes biologization in terms of redefinition, which involves changing the definition of terms sharing the same extension. Redefinition obtains through triangulation and calibration, that is, respectively, detection of an object from two different spots, and tweaking parameters of detection in order to optimize the picture. The unity of the different views of the (...) same object does not occur through derivation from one of them, as reduction suggests, nor does it obtain through mechanistic unity or the goal of explaining one mechanism, as the phrase ‘mosaic unity’ suggests. Instead, it depends on finding a specific angle of observation, from which linguistic consistency matches sound localization in the brain, so that all observations make sense together, just as an anamorphic picture makes clear sense only when observed from the right spot. (shrink)

La conversion de la France à une politique de « réduction des risques » , est généralement interprétée comme l’indice d’un changement de paradigme en matière de toxicomanie. Il est néanmoins possible de la voir comme une forme de réagencement politique du monde des consommations de drogues, visant à définir de nouveaux seuils, les plus bas possibles, pour l’entrée dans des dispositifs de soin et de service. L’examen des visions du monde sur lesquelles reposent ces équipements politiques, en France comme (...) dans le reste de l’Union européenne, montre d’ailleurs que la vision du monde autonomiste y compose avec d’autres, compensatoires et additives, plus anciennement implantées. C’est sans doute pourquoi on retrouve, à divers niveaux, un véritable décalage entre les mesures volontaristes liées à ces politiques publiques et les contextes dans lesquels elles sont mises en œuvre : qu’il s’agisse des promoteurs, professionnels ou amateurs, ou qu’il s’agisse des destinataires, tout le monde semble s’accommoder d’un fonctionnement minimal de ces dispositifs, vérifiant ainsi une fois de plus la force des liens faibles.The French turn to the so-called « risk reduction policy » , is generally interpreted as a shift of the paradigm of drug addiction policies. One can, nevertheless, see it as a kind of new political layout of the drug addiction field, intended to define new thresholds for one’s entering in the treatment and care devices. When we examine the worldviews which sustain these political equipments , we can see that the autonomist worldview has to come to terms with others, namely : the compensatory and additive ones. That is probably why we can see, at various levels, a real discrepancy between the strong willings supporting the actions promoted by the risk reduction policies, and the contexts in which they take place : would it be the main actors , or the beneficiaries, everyone seems to be satisfied with a minimal functioning of these devices, verifying once again the strength of the weak ties. (shrink)

Reduction between theories in physics is often approached as an a priori relation in the sense that reduction is often taken to depend only on a comparison of the mathematical structures of two theories. I argue that such approaches fail to capture one crucial sense of “reduction,” whereby one theory encompasses the set of real behaviors that are well-modeled by the other. Reduction in this sense depends not only on the mathematical structures of the theories, but also on empirical facts (...) about where our theories succeed at describing real systems, and is therefore an a posteriori relation. (shrink)

Scientists and philosophers frequently speak about levels of description, levels of explanation, and ontological levels. This paper presents a framework for studying levels. I give a general definition of a system of levels and discuss several applications, some of which refer to descriptive or explanatory levels while others refer to ontological levels. I illustrate the usefulness of this framework by bringing it to bear on some familiar philosophical questions. Is there a hierarchy of levels, with a fundamental level at the (...) bottom? And what does the answer to this question imply for physicalism, the thesis that everything supervenes on the physical? Are there emergent higher-level properties? Are higher-level descriptions reducible to lower-level ones? Can the relationship between normative and non-normative domains be viewed as one involving levels? And might a levelled framework shed light on the relationship between third-personal and first-personal phenomena? (shrink)

. In this paper, I examine three models of reduction. The first, and the most restrictive, is the model developed by Ernest Nagel as part of the logical empiricist program. The second, articulated by Jerry Fodor, is significantly broader, but it seems unable to make sense of a salient feature of scientific practice. The third, and the most lenient, model is developed within Newton da Costa and Steven French’s partial structures approach. I argue that the third model preserves the benefits (...) of Fodor’s proposal, and it is still able to accommodate relevant aspects of scientific practice. In particular, it offers a conception of reduction without reductionism, and an account of the relation between reduced and reducing theories via unsharp mappings and partial structures—even in the presence of incomplete information. (shrink)

Atomistic metaphysics motivated an explanatory strategy which science has pursued with great success since the scientific revolution. By decomposing matter into its atomic and subatomic parts physics gave us powerful explanations and accurate predictions as well as providing a unifying framework for the rest of science. The success of the decompositional strategy has encouraged a widespread conviction that the physical world forms a compositional hierarchy that physics and other sciences are progressively articulating. But this conviction does not stand up to (...) a closer examination of how physics has treated composition, as a variety of case studies will show. (shrink)

Effective field theories have been a very popular tool in quantum physics for almost two decades. And there are good reasons for this. I will argue that effective field theories share many of the advantages of both fundamental theories and phenomenological models, while avoiding their respective shortcomings. They are, for example, flexible enough to cover a wide range of phenomena, and concrete enough to provide a detailed story of the specific mechanisms at work at a given energy scale. So will (...) all of physics eventually converge on effective field theories? This paper argues that good scientific research can be characterised by a fruitful interaction between fundamental theories, phenomenological models and effective field theories. All of them have their appropriate functions in the research process, and all of them are indispensable. They complement each other and hang together in a coherent way which I shall characterise in some detail. To illustrate all this I will present a case study from nuclear and particle physics. The resulting view about scientific theorising is inherently pluralistic, and has implications for the debates about reductionism and scientific explanation. (shrink)

In a recent critique of the doctrine of emergentism championed by its classic advocates up to C. D. Broad, Jaegwon Kim (Philosophical Studies 63:31–47, 1999) challenges their view about its applicability to the sciences and proposes a new account of how the opposing notion of reduction should be understood. Kim is critical of the classic conception advanced by Nagel and uses his new account in his criticism of emergentism. I question his claims about the successful reduction achieved in the sciences (...) and argue that his new account has not improved on Nagel’s and that the critique of emergentism he bases on it is question-begging in important respects. (shrink)

Rom Harré thinks that the Emergence–Reduction debate, conceived as a vertical problem, is partly ill posed. Even if he doesn’t wholly reject the traditional definition of an emergent property as a property of a collection but not of its components, his point is that this definition doesn’t exhaust all the dimensions of emergence. According to Harré there is another kind (or dimension) of emergence, which we may call—somewhat paradoxically—“horizontal emergence”: two properties of a substance are horizontally emergent relative to each (...) other if they cannot be displayed in the same conditions. Contrary to vertical emergence, horizontal emergence is a symmetrical relation. Harré endorses horizontal emergentism. I argue that this position faces a principled difficulty: it makes it impossible to bind different horizontally emergent discourses in an interesting way. Physics and biology for example become “island” discourses, each speaking of a distinct kind of entities. The only way to ensure that two different discourses can relate to the same entity is to reintroduce verticality into the picture. (shrink)

We reconsider the Nagelian theory of reduction and argue that, contrary to a widely held view, it is the right analysis of intertheoretic reduction. The alleged difficulties of the theory either vanish upon closer inspection or turn out to be substantive philosophical questions rather than knock-down arguments.

In 1973, Nickles identified two senses in which the term `reduction' is used to describe the relationship between physical theories: namely, the sense based on Nagel's seminal account of reduction in the sciences, and the sense that seeks to extract one physical theory as a mathematical limit of another. These two approaches have since been the focus of most literature on the subject, as evidenced by recent work of Batterman and Butterfield, among others. In this paper, I discuss a third (...) sense in which one physical theory may be said to reduce to another. This approach, which I call `dynamical systems reduction,' concerns the reduction of individual models of physical theories rather than the wholesale reduction of entire theories, and specifically reduction between models that can be formulated as dynamical systems. DS reduction is based on the requirement that there exist a function from the state space of the low-level model to that of the high-level model that satisfies certain general constraints and thereby serves to identify quantities in the low-level model that mimic the behavior of those in the high-level model - but typically only when restricted to a certain domain of parameters and states within the low-level model. I discuss the relationship of this account of reduction to the Nagelian and limit-based accounts, arguing that it is distinct from both but exhibits strong parallels with a particular version of Nagelian reduction, and that the domain restrictions employed by the DS approach may, but need not, be specified in a manner characteristic of the limit-based approach. Finally, I consider some limitations of the account of reduction that I propose and suggest ways in which it might be generalised. I offer a simple, idealised example to illustrate application of this approach; a series of more realistic case studies of DS reduction is presented in another paper. (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)

The causal theory of reference (CTR) provides a well-articulated and widely-accepted account of the reference relation. On CTR the reference of a term is fixed by whatever property causally regulates the competent use of that term. CTR poses a metaethical challenge to realists by demanding an account of the properties that regulate the competent use of normative predicates. CTR might pose a challenge to ethical theorists as well. Long argues that CTR entails the falsity of any normative ethical theory. First-order (...) theory attempts to specify what purely descriptive property is a fundamental right-making property (FRM). Long contends that the notion that the FRM causally regulates competent use of the predicate ‘right’ leads to a reductio. The failure of this argument is nevertheless instructive concerning a point at which ethics and metaethics overlap. (shrink)

This study of inter-theoretic reduction and reductionism in biology explores problems logical empiricist approaches face in giving a meaning analysis of reduction, and three real issues in biology involving reductionism: teleology and evolution, levels of organization, and the reduction of Mendelian to molecular genetics. ;It is denied that there is an answer to the logical empiricist question, "What single correct reduction concept is universally and realistically applicable to all science?" The question is unsatisfactory. First, it presupposes that philosophy of science (...) concepts like 'reduction' have meaning in isolation, the same meaning across all variation in their associated philosophical, scientific, formal, and ordinary language contexts. Second, it hopes that reduction so analyzed will have significant application to real science. But the presupposition is undercut by the failure of the analytic/synthetic distinction and the hope is not borne out by scrutiny of reductionism in biology. ;A radical reversal of perspective is in order. Rather than expecting science to conform to philosophy of science concepts concocted in a vacuum of abstraction from context, we should ask, "For a given context, what concept of reduction is appropriate for that context?" This alternative approach is argued for by exposing the weakness inherent in the strategy of meaning analysis logical empiricists use, and by the study of the cited real issues in biology. (shrink)

That the mental is nothing but the physical, that the macroscopic is nothing but the microscopic, that the prescriptive is nothing but the descriptive--these are standard nothing-but claims, dependably controversial. To really settle whether one of these claims is true or false, what sort of evidence would one have to have? I try to formulate a criterion for culling false nothing-but claims from true by clarifying the concept of ontological reduction. A claim that x is nothing but y is true, (...) I maintain, if x is identical to y or if x does not exist, 'x' being a mistaken designation for y . Otherwise it is false. ;The dissertation has five chapters. Since a certain sort of ontological reducibility is to serve as a criterion for acceptable nothing-but claims, what counts as an ontological reduction occupies Chapter One. Four criteria are rounded up before two of them are rejected for their radically Pythagorean consequences. One of the rejected criteria, due to Quine, could perhaps be emended so as to block these Pythagorean consequences. Chapter Two argues that, even if this could be done, the criterion would still be unacceptable; it trivializes ontological endeavor, and its philosophical presuppositions imply a falsehood . Combined, the two non-Pythagorean criteria of Chapter One are presented as a necessary and sufficient condition for ontological reduction. Chapter Three distinguishes other kinds of reduction. Besides ontological reduction, there are theoretical reduction and theoretical replacement. I hold that instances of one of these kinds of reduction need not be instances of the others, and that only certain kinds of ontological reduction are directly relevant to the assessment of nothing-but claims. The resulting conceptual grid is applied to contemporary nothing-but claims in the final two chapters. Chapter Four contends that certain claims advanced on the basis of supervenience relations are philosophically unsound, while Chapter Five holds that other claims connected with the functionalist philosophy of mind are philosophically sound, though empirically undecided. (shrink)