科学におけるメカニズム - スタンフォード哲学百科事典

Mechanisms in Science (Stanford Encyclopedia of Philosophy) Stanford Encyclopedia of Philosophy Menu Browse Table of Contents What's New Random Entry Chronological Archives About Editorial Information About the SEP Editorial Board How to Cite the SEP Special Characters Advanced Tools Contact Support SEP Support the SEP PDFs for SEP Friends Make a Donation SEPIA for Libraries Entry Navigation Entry Contents Bibliography Academic Tools Friends PDF Preview Author and Citation Info Back to Top Mechanisms in Science First published Wed Nov 18, 2015; substantive revision Thu Aug 1, 2024 The concept of mechanism has been an important organizing principle in science and philosophy since at least the early modern period (Dijksterhuis 1950 [1961]; Boas 1952). The nature of that organizing principle, and precisely how it scaffolds the organization of material knowledge, has changed considerably over time. In late twentieth century philosophy of science, the term “mechanism” came to stand for a kind of theoretical structure according to which some capacity or behavior of a whole or an endstate of a process is explained in terms of the organization and activities of components or antecedents. The goal of discovering mechanisms is an explicit, guiding aim for many contemporary sciences, especially the special sciences. But what is a mechanism? Why is mechanistic knowledge so important? How is it related to the primary goals of science, such as prediction, explanation and control? Are there general strategies guiding the search for mechanisms? Are mechanisms “real”? How are mechanisms at different levels related to one another? What is required of a mechanistic explanation? And what are the characteristic fallacies of mechanistic explanation? This family of questions, and others besides, became a major focus in the philosophy of science at the turn of the twenty-first century. The philosophers who took up these questions in earnest tended to approach the topic through detailed case studies from key developments in twentieth century biology, with particular attention to the assumptions, constraints, and norms revealed through scientific practice (see, e.g., Bechtel & Richardson 1993; Thagard 2000; Darden 2005; Craver 2007; Craver & Darden 2013). Here we discuss the many areas of the philosophy of science in which the concept of mechanism has been deployed to make explicit and transparent key aspects of the scientific enterprise. 1. Why Did the “New Mechanism” Emerge in Late-Twentieth Century Philosophy of Science? 2. What Is a Mechanism? 2.1 Depicting Mechanisms 2.1.1 Phenomenon 2.1.2 Parts 2.1.3 Cause 2.1.4 Organization 2.1.5 Levels 2.2 What Mechanisms Are Not 2.3 What Are Not Mechanisms 3. Why Does So Much Scientific Practice Revolve Around Mechanistic Explanation? 3.1 Etiological and Constitutive Causal-Mechanical Explanations 3.2 Limits of the CL Model of Constitutive Explanations 3.3 Purely Phenomenal Models 3.4 Constitutive Explanatory Relevance 3.4.1 Against Causation Across Levels of Mechanisms 3.4.2 Constitutive Relevance as Mutual Manipulability 3.5 Completeness and Correctness 3.5.1 Completeness 3.5.2 Correctness 3.6 Intelligibility 4. How Do Scientists Discover Mechanisms? 4.1 Strategies of Discovery 4.2 Mechanistic Evidence and Medical Discoveries 5. Are Mechanisms Real? 5.1 Mechanisms Are Defined Relative to Phenomena 5.2 Dividing Mechanisms into Parts 5.3 Functions 5.4 Kinds of Mechanisms and Mechanism Boundaries 5.5 Grades of Perspectival Realism 6. How Do Different Scientific Disciplines Relate to One Another? 6.1 Explanatory Reductionism 6.2 Ontological Reductionism 6.2.1 Mechanism, Reduction, and Emergence 6.2.2 Mechanism and Realization 6.3 Interfield integration and Integrative Pluralism 7. Conclusion Bibliography Academic Tools Other Internet Resources Related Entries 1. Why Did the “New Mechanism” Emerge in Late-Twentieth Century Philosophy of Science? The term “mechanism” has been used both as a laudatory term, expressing the highest achievement of a given domain (especially science and metaphysics), and as a term of derision, representing a blinkered view of science or a narrow, lifeless, and bleak philosophical orientation toward the world (Nicholson 2013; Dupré & Nicholson 2018). The mechanism of the seventeenth century, as articulated by Descartes , Gassendi , and Boyle , was not univocal but came to be associated with commitments to the unity of matter and the ultimate explicability of all change in terms of local motion and contact action (see Boas 1952; Dijksterhuis 1950 [1961]; Gabbey 2004; Garber 1992; Roux 2017). This form of mechanism emerged largely as a reaction to Aristotelian emphases on formal and final causes. The banner of “mechanism” was used as a rallying cry in various times and places and sciences in the nineteenth and twentieth century (see, e.g., Allen 2005; Nicholson 2014. For example, see Loeb as discussed in Pauly 1987 or Helmholz as discussed in Sulloway 1979). It embodied the ideals of the science: to mathematize, to find deterministic laws, to render things intelligible via assimilation to contact action. In many cases, advocacy for mechanism was largely a reaction to and would-be vanquisher of forms of organicism and vitalism . No single person held all these views, and arguably no single view is common among them all. In contrast to these earlier instantiations, the so-called “New Mechanism” of the late twentieth and early twenty-first centuries developed as a reaction to and would be successor of logical empiricist approaches to the philosophy of science . In that service, the material commitments of mechanistic views conflicted with the content-neutral, formal emphasis of the logical empiricists. The methodology, moreover, took seriously the idea that what one could say about the structure of an explanation, theory, or science must be responsive not only to the demands of logical rigor but also to the facts about science as practiced. The origins of the New Mechanism trace, almost without exception, to programs in the history and philosophy of science, such as the Conceptual Foundations of Science (CFS) Program at the University of Chicago, and the History and Philosophy of Science Department (HPS) at the University of Pittsburgh, or both, in the 1970s. Students and faculty at the University of Chicago, included Lindley Darden (CFS), Jon Elster (Philosophy; Political Science), Stuart Kauffman (Biology), Richard Levins (Biology), William Lycan (Philosophy), Ken Schaffner (CFS), Bill Bechtel (CFS), Bob Richardson (CFS) and, later, Stuart Glennan (CFS). A converging strand of development ran through the University of Pittsburgh: Peter Machamer and Schaffner (both trained at Chicago and later joined HPS), Wesley Salmon and John Haugeland (Philosophy), and their student, Carl Craver (HPS). This sociological fact helps explain the case-based methodology of the new mechanists: they were especially attentive to the details of historical exemplars of science as practiced: e.g., how claims are tested, how models are related to the world, how explanations and experiments are evaluated. They emphasized that the language of contemporary biomedical and physiological sciences is animated by background assumptions about mechanisms. That historical fact, they argued, offers a window on the structure of the special sciences generally. This historical, practice-centered approach built upon the criticisms of logical empiricism by, for example, Kuhn (1962), Lakatos (1977), and Laudan (1977). But importantly, mechanists saw in the concept of a mechanism a fecund, material alternative to the logical structure at the backbone of the increasingly anomaly-ridden, formal approaches of logical empiricism. The new mechanists presented their work as a unified treatment of the norms governing work in the special sciences that, importantly, was modeled on what scientists actually say and do when they make discoveries, test models, evaluate explanations, integrate levels, and the like. These mechanists built this alternative picture by drawing together strands from philosophy, theoretical biology, and artificial intelligence and showing them at work in their case studies. Herbert Simon’s (1969) Sciences of the Artificial introduced the idea of nested “hierarchies” of “nearly decomposable systems” as heuristics for understanding complex systems. Stuart Kaufman (1971 [1976]) developed an account of “articulation of parts explanations” in developmental biology. Lycan (1990) saw in levels of explanation a metaphysical alternative to reductionism as a viable scientific worldview. Wimsatt (1976a, 1976b, 1997) was for many early mechanists a crucial figure connecting this theoretical work to discussions of reduction and emergence in the philosophy of science. These strands began to coalesce into an overarching perspective with Bechtel and Richardson’s (1993 [2010]) Discovering Complexity . That book introduced the idea of mechanism as a scaffold for a model of scientific discovery grounded in reverse engineering methods such as decomposition and localization. The next major step in this development, discussed in Section 3 , connected this budding view with Wesley Salmon’s defense of a causal-mechanical theory of scientific explanation. 2. What Is a Mechanism? The first decade of philosophical work in the new mechanism was directed at defining the concept of mechanism. Glennan’s definition was arguably the first: A mechanism underlying a behavior is a complex system which produces that behavior by… the interaction of parts according to direct causal laws. (Glennan 1996: 52). Within a decade, definitions multiplied, each with its own commitments and implications: Mechanisms are entities and activities organized such that they are productive of regular changes from start or set-up to termination conditions. (Machamer, Darden, & Craver 2000: 3) MECH: a necessary condition for a representation to be an acceptabl