. Introductory Remarks THEODOSIUS DOBZHANSKY The problems of reduction in biology are currently of considerable theoretical interest and practical ...

This essay analyzes and develops recent views about explanation in biology. Philosophers of biology have parted with the received deductive-nomological model of scientific explanation primarily by attempting to capture actual biological theorizing and practice. This includes an endorsement of different kinds of explanation (e.g., mathematical and causal-mechanistic), a joint study of discovery and explanation, and an abandonment of models of theory reduction in favor of accounts of explanatory reduction. Of particular current interest are philosophical accounts of complex (...) explanations that appeal to different levels of organismal organization and use contributions from different biological disciplines. The essay lays out one model that views explanatory integration across different disciplines as being structured by scientific problems. I emphasize the philosophical need to take the explanatory aims pursued by different groups of scientists into account, as explanatory aims determine whether different explanations are competing or complementary and govern the dynamics of scientific practice, including interdisciplinary research. I distinguish different kinds of pluralism that philosophers have endorsed in the context of explanation in biology, and draw several implications for science education, especially the need to teach science as an interdisciplinary and dynamic practice guided by scientific problems and explanatory aims. (shrink)

There is unquestionably a plethora of details and mysteries regarding the mind and the body. However, with the advent of psychopharmacology (the study of how psychedelics inform or alter brain states) there are more issues at hand. Do psychedelics allow us to access deeper areas of our consciousness? Are we having a spiritual experience under the influence of psychedelics? Dr. Rick Strassman does not want to continue asking these rather conspiratorial-like questions. Instead, Dr. Strassman believes that there is one special, (...) endogenous psychedelic, synthesized within the human physiological framework: N, N-Dymthethyltryptamine. Dr. Strassman concludes that this chemical is produced within and around the pineal gland, and is often the catalyst for spiritual and religious experiences. I will explore this topic further under the framework of discovering whether a naturalistic type explanation of spiritual experiences accounts for all types of spiritual experiences and whether one may be rational or justified in believing in God if a naturalist could explain spiritual experiences. (shrink)

Should the philosophy of biology deal with organismic, or with molecular aspects , or with both ? We are, of course, not the first to appreciate the ...

Back cover: This book develops a philosophical account that reveals the major characteristics that make an explanation in the life sciences reductive and distinguish them from non-reductive explanations. Understanding what reductive explanations are enables one to assess the conditions under which reductive explanations are adequate and thus enhances debates about explanatory reductionism. The account of reductive explanation presented in this book has three major characteristics. First, it emerges from a critical reconstruction of the explanatory practice of the life sciences itself. (...) Second, the account is monistic since it specifies one set of criteria that apply to explanations in the life sciences in general. Finally, the account is ontic in that it traces the reductivity of an explanation back to certain relations that exist between objects in the world (such as part-whole relations and level relations), rather than to the logical relations between sentences. Beginning with a disclosure of the meta-philosophical assumptions that underlie the author’s analysis of reductive explanation, the book leads into the debate about reduction(ism) in the philosophy of biology and continues with a discussion on the two perspectives on explanatory reduction that have been proposed in the philosophy of biology so far. The author scrutinizes how the issue of reduction becomes entangled with explanation and analyzes two concepts, the concept of a biological part and the concept of a level of organization. The results of these five chapters constitute the ground on which the author bases her final chapter, developing her ontic account of reductive explanation. (shrink)

Background: how mind functions is subject to continuing scientific discussion. A simplistic approach says that, since no convincing way has been found to model subjective experience, mind cannot exist. A second holds that, since mind cannot be described by classical physics, it must be described by quantum physics. Another perspective concerns mind's hypothesized ability to interact with the world of quanta: it should be responsible for reduction of quantum wave packets; physics producing 'Objective Reduction' is postulated to form (...) the basis for mind-matter interactions. This presentation describes results derived from a new approach to these problems. It is based on well-established biology involving physics not previously applied to the fields of mind, or consciousness studies, that of critical feedback instability. -/- Methods: 'self-organized criticality' in complexity biology places system loci of control at critical instabilities, physical properties of which, including information properties, are presented. Their elucidation shows that they can model hitherto unexplained properties of experience. -/- Results: All results depend on physical properties of critical instabilities. First, at least one feed-back or feed-forward loop must have feedback gain, g = 1: information flows round the loop impress perfect images of system states back on themselves: they represent processes of perfect self-observation. This annihilates system quanta: system excitations are instability fluctuations, which cannot be quantized. Major results follow: -/- 1. Information vectors representing criticality states must include at least one attached information loop denoting self-observation. -/- 2. Such loop structures are attributed a function, 'registering the state's own existence', explaining -/- a. Subjective 'awareness of one's own presence' -/- b. How content-free states of awareness can be remembered (Jon Shear) -/- c. Subjective experience of time duration (Immanuel Kant) -/- d. The 'witness' property of experience – often mentioned by athletes 'in the zone' -/- e. The natural association between consciousness and intelligence -/- This novel, physically and biologically sound approach seems to satisfactorily model subjectivity. -/- Further significant results follow: -/- 1. Registration of external information in excited states of systems at criticality reduces external wave-packets: the new model exhibits 'Objective Reduction' of wave packets. -/- 2. High internal coherence (postulated by Domash & Penrose) leading to a. Non-separable information vector bundles. b. Non-reductive states (Chalmers's criterion for experience). -/- 3. Information that is: a. encoded in coherence negentropy; b. non-digitizable, and therefore c. computationally without digital equivalent (posited by Penrose). -/- Discussion and Conclusions: instability physics implies anharmonic motion, preventing excitation quantization, and totally different from the quantum physics of simple harmonic motion at stability. Instability excitations are different from anything hitherto conceived in information science. They can model aspects of mind never previously treated, including genuine subjectivity, objective reduction of wave-packets, and inter alia all properties given above. (shrink)

I attempt to characterize the relationship of classical experimental embryology (CEE) and molecular developmental biology and compare it to the much-discussed case of classical genetics. These sciences are treated here as discovery practices rather than as definitive forms of knowledge. I first show that CEE had some causal knowledge and hence was able to answer specific why?-questions. A paradigm was provided by the case of eye induction, perhaps CEE’s greatest success. The case of the famous Spemann-Mangold organizer is more difficult. (...) I argue that before the advent of molecular biology, knowledge of its causal role in development was very limited. As a result, there was no functional definition of the concept of organizer. I argue that, like the classical gene concept, it is best viewed as an operational concept. This means that an account of reduction such as Kim’s functional reduction, which is still a mainstay in scientific metaphysics, cannot work in these cases. Nonetheless, again like in the classical gene case, the operational concepts of CEE played an important heuristic role in the discovery of molecules involved in morphogenesis and cell differentiation. This was made possible by what I call inter-level investigative practices. These are practices that combine experimental manipulations targeting two (or more) different levels. I conclude that the two sciences are more closely related via their experimental practices than by any inter-level explanatory relations. (shrink)

It is widely assumed that selection history accounts of function can support a fully reductive naturalization of functional properties. I argue that this assumption is false. A problem with the alternative causal role account of function in this context is that it invokes the teleological notion of a goal in analysing real function. The selection history account, if it is to have reductive status, must not do the same. But attention to certain cases of selection history in biology, specifically those (...) involving meiotic drive, shows that selection historical explanations are available in the case of items without any plausible function. Making contributions to goals, here fitness, must be introduced as an additional constraint in the analysis, either explicitly, or implicitly by appeal to individual functions or the selection-of/selection-for distinction. (shrink)

The paper works towards an account of explanatory integration in biology, using as a case study explanations of the evolutionary origin of novelties-a problem requiring the integration of several biological fields and approaches. In contrast to the idea that fields studying lower level phenomena are always more fundamental in explanations, I argue that the particular combination of disciplines and theoretical approaches needed to address a complex biological problem and which among them is explanatorily more fundamental varies with the (...) problem pursued. Solving a complex problem need not require theoretical unification or the stable synthesis of different biological fields, as items of knowledge from traditional disciplines can be related solely for the purposes of a specific problem. Apart from the development of genuine interfield theories, successful integration can be effected by smaller epistemic units (concepts, methods, explanations) being linked. Unification or integration is not an aim in itself, but needed for the aim of solving a particular scientific problem, where the problem's nature determines the kind of intellectual integration required. (shrink)

A belief common among philosophers and biologists alike is that Mendelian genetics has been or is in the process of being reduced to molecular genetics, in the sense of formal theory reduction current in the literature. The purpose of this paper is to show that there are numerous empirical and conceptual difficulties which stand in the way of establishing a systematic inferential relation between Mendelian and molecular genetics. These difficulties, however, have little to do with the traditional objections which (...) have been raised to reduction. (shrink)

The historical development of debates about reduction testifies to us that reductionism in biology must proceed by providing a precise and complete causal explanation for every biological phenomenon at the level of molecules. An intertheoretical reduction model was proposed in biology but proved unsuccessful due to its inability to accommodate and explain the success of molecular biology. Ever since the molecular structure of the gene was discovered, actual biological research has successfully generated explanations for complex (...) class='Hi'>biological facts in terms of the predicates of molecular biology. Biological phenomena, which classical functional biology explains only with limited powers, are more accurately described and comprehensively explained as the reduction processes advance with molecular biology. It is clear that the reductionist research program of molecular biology is the best account of success and progress in biology. (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)

Watson and Crick’s discovery of the structure of DNA led to developments that transformed many biological sciences. But what were the relevant developments and how did they transform biology? Much of the philosophical discussion concerning this question can be organized around two opposing views: theoretical reductionism and layer-cake antireductionism. Theoretical reductionist and their anti-reductionist foes hold two assumptions in common. First, both hold that biological knowledge is structured like a layer cake, with some biological sciences, such as (...) molecular biology cast at lower levels of organization, and others, such as classical genetics, cast at higher levels. Second, both assume that scientific knowledge is structured by theory and that the productivity of scientific research depends on whether the underlying theory identifies the fundamentals upon which the phenomena to be explained and investigated depend. In the first part of this paper, I challenge these assumptions. In the second part, I show how recasting the basic theory of classical genetics made it possible to retool the methodologies of genetics. It was the investigative power of these retooled methodologies, and not the explanatory power of a gene-based theory, that transformed biology. (shrink)

A major theme in biological research is the quest for mechanism, embodied in explanatory reductionism: the interpretation of phenomena through links to the entities and laws of more fundamental sciences. For example, the form of Starling's Law of the Heart, relating contractile force to heart volume, follows from the sliding-filament hypothesis of muscle contraction, a molecular concept. Although alternative mechanisms for muscle contraction and cardiac regulation could be deduced from biochemical principles, the formulation provides clear correspondence with the phenomena (...) and a deeper understanding of cardiac function. Moreover, even if the reduction provides no better formulation of the phenomenon, of the macro-regularity, it is still prized as a nearer approach to physical reality, as a step toward realizing fundamental unities and codifying general principles, and as a door to new experimental opportunities. (shrink)

The general aim of this paper is to propose a reductionist strategy to higher-level property types. Starting from a common ground in the philosophy of science, I shall elaborate on possible realizer differences of higher-level property types. Because of the realizer types' causal heterogeneity, an introduction of functional sub-types of higher-level properties will be suggested. Each higher-level functional sub-type corresponds to one realizer type. This means that there is the theoretical possibility to reach some kind of type-identity and this opens (...) up the way for theory reduction in a more complete manner. This kind of type-identity will go beyond the common ground of the identity of tokens and their reductive explanation. In the second part of the paper, this reductionist strategy will be applied to a specific debate in the philosophy of biology — the reductionist approach to classical genetics from a molecular point of view. (shrink)

In this paper I shall discuss the concept of reduction—ontological, methodological, and epistemological or theoretical—in the biological sciences, with special emphasis on genetics and evolutionary biology. I suggest that perhaps, because the biological world has a form different from the non-biological world, it is appropriate to think of terms or metaphors different from those we would use when trying to understand the inorganic world. As such, the attempt to show that the biological is simply a (...) deductive consequence of the physicochemical is doomed to failure. The philosophical complexity of reductionism on the one hand and its potential for advancing the study of biology on the other thus requires continuing the ongoing dialogue between philosophers and biologists. (shrink)

In the middle of the twentieth century, Wittgenstein warned that “the method of reducing the explanation of natural phenomena to the smallest possible number of primitive natural laws…leads…into complete darkness” (1958, p. 18). At the time, few philosophers and even fewer scientists were prepared to heed his warning. A half-century later, however, the reductive method of science—the method famously defined by Descartes, brilliantly exemplified by Newtonian physics, and long upheld as the gold standard of scientific explanation—seems to have finally lost (...) its luster. While reduction is still widely defended, in the last decades alternative views have gained credibility, to the extent that a “non-reductive science” is no longer dismissed as an oxymoron. (shrink)

This paper examines the nature of theory structure in biology and considers the implications of those theoretical structures for theory reduction. An account of biological theories as interlevel prototypes embodying causal sequences, and related to each other by strong analogies, is presented, and examples from the neurosciences are provided to illustrate these middle-range theories. I then go on to discuss several modifications of Nagel''s classical model of theory reduction, and indicate at what stages in the development of (...) reductions these models might best apply. Finally I consider several implications of these analyses of theory structure and reduction for disciplinary integration in biology. (shrink)

The inapplicability of variations on theory reduction in the context of genetics and their irrelevance to ongoing research has led to an anti-reductionist consensus in philosophy of biology. One response to this situation is to focus on forms of reductive explanation that better correspond to actual scientific reasoning (e.g. part–whole relations). Working from this perspective, we explore three different aspects (intrinsicality, fundamentality, and temporality) that arise from distinct facets of reductive explanation: composition and causation. Concentrating on these aspects generates (...) new forms of reductive explanation and conditions for their success or failure in biology and other sciences. This analysis is illustrated using the case of protein folding in molecular biology, which demonstrates its applicability and relevance, as well as illuminating the complexity of reductive reasoning in a specific biological context. (shrink)

The applicability of Nagel's concept of theory reduction, and related concepts of reduction, to the reduction of genetics to molecular biology is examined using the lactose operon in Escherichia coli as an example. Geneticists have produced the complete nucleotide sequence of two of the genes which compose this operon. If any example of reduction in genetics should fit Nagel's analysis, the lactose operon should. Nevertheless, Nagel's formal conditions of theory reduction are inapplicable in this case. (...) Instead, it is argued that genetics has been partially reduced to molecular biology in the sense of token-token reduction. (shrink)

Many biologists and philosophers have worried that importing models of reasoning from the physical sciences obscures our understanding of reasoning in the life sciences. In this paper we discuss one example that partially validates this concern: part-whole reductive explanations. Biology and physics tend to incorporate different models of temporality in part-whole reductive explanations. This results from differential emphases on compositional and causal facets of reductive explanations, which have not been distinguished reliably in prior philosophical analyses. Keeping these two facets distinct (...) facilitates the identifi cation of two further aspects of reductive explanation: intrinsicality and fundamentality. Our account provides resources for discriminating between different types of reductive explanation and suggests a new approach to comprehending similarities and differences in the explanatory reasoning found in biology and physics. (shrink)

Supervenience is a relationship which has been used recently to explain the physical determination of biological phenomena despite resistance to reduction. Supervenience, however, is plagued by ambiguities which weaken its explanatory value and obscure some interesting aspects of reduction in biology. Although I suspect that similar considerations affect the use of supervenience in ethics and the philosophy of mind, I don’t intend anything I have to say here to apply outside of the physical and biological cases (...) I consider.The main point of this paper is that there is a property of biological systems which makes it both misleading and inappropriate to reduce central biological phenomena to the properties of underlying components. Despite this, reductive explanation has been a major source of innovation in biological theory. The apparent tension can be resolved if underlying properties are explanatorily relevant to the higher level phenomena even though the latter are not strictly reducible to the former. Supervenience, I will argue, is not robust enough to deny reduction while supporting explanatory relevance. (shrink)

The main claim in this paper is that because organisms have teleological constitutions, the reduction of biology to physical science is not possible. It is argued that the teleology of organisms is intrinsic and not merely projected onto them. Many organic phenomena are end-oriented and reference to ends is necessary for explaining them. Accounts in terms of functions or goals are appropriate to organic parts and processes. siis is because ends as systemic requirements for survival and health have explanatory (...) significance with respect to the processes that contribute to and constitute them. Reductionism cannot accommodate this sort of higher-level to lower-level explanation and so cannot account for why lower-level phenomena are as they are. Reductionism, it is claimed, is ultimately descriptive and not explanatory because it cannot regard teleological requirements as themselves basic. In seeking to explain them away it forfeits explanatory power. (shrink)

Volume 33, Issue 7, October 2020, Page 1045-1048.

The groups of problems that fall under the titles ‘reduction’ and ‘emergence’ appear at the boundaries of seemingly independent and well-established scientific disciplines, such as chemistry and biology, biology and psychology, biology and political theory, and so on. They arise in this way.

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)

In this paper, I argue that starting with the organelles that constitute a cell - and continuing up the hierarchy of components in processes and subsystems of an organism - there exist clear instances of emergent biological phenomena that can be considered,,living" entities. These components and their attending processes are living emergent phenomena because of the way in which the components are organized to maintain homeostasis of the organism at the various levels in the hierarchy. I call this view (...) the homeostatic organization view of biological phenomena, and, as is shown, it comports well with the standard philosophical accounts of nomological emergence and representational emergence. To proffer HOV, I describe properties of biological entities that include internal-hierarchical data exchange, data selectivity, informational integration, and environmental-organismic information exchange. Further, a distinction is drawn between particularized homeostasis and generalized homeostasis, and I argue that because the various processes and subsystems of an organism are functioning properly in their internal environments, the organism is able to exist as a hierarchically-organized entity in some environment external to it. Stated simply: that components of biological phenomena are organized to perform some function resulting in homeostasis marks them out to be living emergent entities distinguishable, in description and in reality, from the very physico-chemical processes of which they are composed. German In diesem Aufsatz argumentiere ich dafür, daß - beginnend mit den Organellen, die eine Zelle bilden und die Hierarchie der Komponenten von Prozessen und Subsystemen eines Organismus hinaufführend - klare Fälle emergenter biologischer Phänomene existieren, die als,,lebende Entitäten betrachtet werden können. Diese Komponenten und die sie begleitenden Prozesse sind lebende emergente Phänomene wegen der Art, in der die Komponenten organisiert sind, um die Homöostase des Organismus auf den verschiedenen Ebenen in der Hierarchie aufrechtzuerhalten. Ich nenne diese Sichtweise die homöostatische Organisationssichtweise biologischer Phänomene, und es wird gezeigt, daß sie sich gut mit üblichen philosophischen Darstellungen nomologischer Emergenz und repräsentationaler Emergenz verträgt. Um HOV zu präsentieren, beschreibe ich Eigenschaften biologischer Entitäten, die den intern-hierarchischen Datenaustausch, die Datenselektivität, die informationelle Integration und den Umwelt-Organismus-Informationsaustausch einschließen. Des weiteren wird eine Unterscheidung zwischen partikularisierter und generalisierter Homöostase getroffen, und ich argumentiere dafür, daß ein Organismus fähig ist, als eine hierarchisch organisierte Entität in einigen Umwelten, die ihm extern sind, zu existieren, weil die verschiedenen Prozesse und Subsysteme eines Organismus in ihren internen Umwelten richtig funktionieren. Einfach formuliert: Daß Komponenten biologischer Phänomene organisiert sind, um eine Funktion zu erfüllen, die in Homöostase resultiert, zeichnet sie aus, lebende emergente Entitäten zu sein, die - in der Beschreibung und in der Wirklichkeit - von den physikalisch-chemischen Prozessen, aus denen sie zusammengesetzt sind, unterscheidbar sind. (shrink)

Reductive explanations are psychologically seductive; when given two explanations, people prefer the one that refers to lower-level components or processes to account for the phenomena under consideration even when information about these lower levels is irrelevant (Hopkins, Weisberg, and Taylor 2016). Maybe individuals assume that a reductive explanation is what a scientific explanation should look like (e.g., neuroscience should explain psychology) or presume that information about lower-level components or processes is more explanatory (e.g., molecular detail explains better than anatomical detail). (...) Philosophers have been analyzing reduction for more than half a century (Hüttemann and Love 2016), but neither of these possibilities is a consensus view (even if psychologically applicable). Instead, there is widespread agreement that the landscape of reductionism is complicated, especially in biology (Brigandt and Love 2017). Increasing scrutiny of actual practices within biology and other sciences has often provoked the questions (paraphrasing Alasdair MacIntyre): Whose explanation? Which reductionism? Marie Kaiser’s book—Reductive Explanation in the Biological Sciences—is a decisive intervention into these discussions, offering a wealth of helpful distinctions and new analyses with a healthy focus on scientific practices of explanation. (shrink)

Reduction and reductionism have been central philosophical topics in analytic philosophy of science for more than six decades. Together they encompass a diversity of issues from metaphysics and epistemology. This article provides an introduction to the topic that illuminates how contemporary epistemological discussions took their shape historically and limns the contours of concrete cases of reduction in specific natural sciences. The unity of science and the impulse to accomplish compositional reduction in accord with a layer-cake vision of (...) the sciences, the seminal contributions of Ernest Nagel on theory reduction and how they strongly conditioned subsequent philosophical discussions, and the detailed issues pertaining to different accounts of reduction that arise in both physical and biological science (e.g., limit-case and part-whole reduction in physics, the difference-making principle in genetics, and mechanisms in molecular biology) are explored. The conclusion argues that the epistemological heterogeneity and patchwork organization of the natural sciences encourages a pluralist stance about reduction. (shrink)

In this paper, I propose two theses, and then examine what the consequences of those theses are for discussions of reduction and emergence. The first thesis is that what have traditionally been seen as robust, reductions of one theory or one branch of science by another more fundamental one are a largely a myth. Although there are such reductions in the physical sciences, they are quite rare, and depend on special requirements. In the biological sciences, these prima facie (...) sweeping reductions fade away, like the body of the famous Cheshire cat, leaving only a smile.... The second thesis is that the "smiles" are fragmentary patchy explanations, and though patchy and fragmentary, they are very important, potentially Nobel-prize winning advances. To get the best grasp of these "smiles," I want to argue that, we need to return to the roots of discussions and analyses of scientific explanation more generally, and not focus mainly on reduction models, though three conditions based on earlier reduction models are retained in the present analysis. I briefly review the scientific explanation literature as it relates to reduction, and then offer my account of explanation. The account of scientific explanation I present is one I have discussed before, but in this paper I try to simplify it, and characterize it as involving field elements and a preferred causal model system abbreviated as FE and PCMS. In an important sense, this FE and PCMS analysis locates an "explanation" in a typical scientific research article. This FE and PCMS account is illustrated using a recent set of neurogenetic papers on two kinds of worm foraging behaviors: solitary and social feeding. One of the preferred model systems from a 2002 Nature article in this set is used to exemplify the FE and PCMS analysis, which is shown to have both reductive and nonreductive aspects. The paper closes with a brief discussion of how this FE and PCMS approach differs from and is congruent with Bickle's "ruthless reductionism" and the recently revived mechanistic philosophy of science of Machamer, Darden, and Craver. (shrink)