pdf version of the entry Reductionism in Biology http://plato.stanford.edu/archives/sum2012/entries/reduction-biology/ Reductionism in Biology from the Summer 2012 Edition of the First published Tue May 27, 2008; substantive revision Mon Apr 30, 2012 Stanford Encyclopedia Reductionism encompasses a set of ontological, epistemological, and methodological claims about the relations between different scientific of Philosophy domains. The basic question of reduction is whether the properties, concepts, explanations, or methods from one scientific domain (typically at higher levels of organization) can be deduced from or explained by the properties, concepts, explanations, or methods from another domain of science (typically one about lower levels of organization). Reduction is Edward N. Zalta Uri Nodelman Colin Allen John Perry germane to a variety of issues in philosophy of science, including the Principal Editor Senior Editor Associate Editor Faculty Sponsor structure of scientific theories, the relations between different scientific Editorial Board disciplines, the nature of explanation, the diversity of methodology, and http://plato.stanford.edu/board.html the very idea of theoretical progress, as well as to numerous topics in Library of Congress Catalog Data metaphysics and philosophy of mind, such as emergence, mereology, and ISSN: 1095-5054 supervenience. Notice: This PDF version was distributed by request to mem- In recent philosophy of biology (1970s to the 1990s), the primary debate bers of the Friends of the SEP Society and by courtesy to SEP content contributors. It is solely for their fair use. Unauthorized about reduction has focused on the question of whether and in what sense distribution is prohibited. To learn how to join the Friends of the classical genetics can be reduced to molecular biology. Although other SEP Society and obtain authorized PDF versions of SEP entries, strands of discussion have been present (e.g., whether evolutionary theory please visit https://leibniz.stanford.edu/friends/ . is inherently anti-reductionist because of the principle of natural selection), philosophical debate about reduction has shifted over the past Stanford Encyclopedia of Philosophy decade to include a wide variety of domains (e.g., development, ecology, Copyright c 2011 by the publisher The Metaphysics Research Lab evolution, cell biology, and neuroscience), and to address additional Center for the Study of Language and Information questions about the nature and status of interdisciplinarity, such as the Stanford University, Stanford, CA 94305 integration of data or standards across biological fields. Philosophical Reductionism in Biology Copyright c 2012 by the authors interest about reduction in biology is pervasive throughout the history of Ingo Brigandt and Alan Love philosophy and science. Many contemporary debates have historical All rights reserved. analogues, reflecting long-standing controversies among biologists about Copyright policy: https://leibniz.stanford.edu/friends/info/copyright/ the legitimacy of reductionist research strategies and modes of 1 Reductionism in Biology Ingo Brigandt and Alan Love explanation used by different life science subdisciplines. relations are quite prevalent). 1. Introduction (i) Ontological reduction is the idea that each particular biological system 2. Historical Background: Philosophical and Scientific (e.g., an organism) is constituted by nothing but molecules and their 3. Models of (Epistemic) Reduction interactions. In metaphysics this idea is often called physicalism (or 3.1 Theory Reduction materialism), which assumes in a biological context that (a) biological 3.2 Explanatory Reduction properties supervene on physical properties (i.e., no difference in a 4. Problems with Reductionism biological property without a difference in some underlying physical 4.1 Context-Dependence of Molecular Features (one-many) property), and (b) each particular biological process (or token) is 4.2 Multiple Realization of Higher Level Features (many-one) metaphysically identical to some particular physico-chemical process. 4.3 Representation, Temporality, and Intrinsicality This latter tenet is sometimes called token-token reduction, in contrast to 5. “Alternatives” to Reductionism: Moving Beyond Dichotomies the stronger tenet that each type of biological process is identical to a type 6. Future Prospects of physico-chemical process. Ontological reduction in this weaker sense Bibliography is a default stance nowadays among philosophers and biologists though Academic Tools the philosophical details remain controversial, such as whether there are Other Internet Resources genuinely emergent properties. Various conceptions of physicalism may Related Entries yield different implications for ontological reduction in biology (Dowell 2006). The denial of physicalism by vitalism, the doctrine that biological systems are governed by forces that are not physico-chemical, is largely 1. Introduction of historical interest. (Vitalism also admits of various conceptions, especially with respect to how non-physico-chemical forces are We reduce and reduce and reduce, but the habits of understood; see Section 2.) Some authors have argued vigorously for the anthropomorphism and metaphor are hard to kill. (Margaret significance of metaphysical concepts in the discussion of reductionism in Drabble, The Sea Lady, 146) biology (Rosenberg 1978, 1985, 1994, 2006). Reduction (reductionism) encompasses several, related philosophical (ii) Methodological reduction is the idea that biological systems are most themes. At least three core types can be distinguished: ontological, fruitfully investigated at the lowest possible level, and that experimental methodological, and epistemic (Sarkar 1992; cf. Nagel 1998). Even studies should be aimed at uncovering molecular and biochemical causes. though arguments for and against reductionism often include a A common example of this type of strategy is the decomposition of a combination of positions related to all three, these distinctions are complex system into parts (Bechtel and Richardson 1993); a biologist significant because no straightforward entailment relations obtain between might investigate the cellular parts of an organism in order to comprehend the different types of reduction (although tacit commitments about these its behavior, or investigate the biochemical components of a cell to 2 Stanford Encyclopedia of Philosophy Summer 2012 Edition 3 Reductionism in Biology Ingo Brigandt and Alan Love understand its features. While methodological reductionism is often (Section 3.2). motivated by the presumption of ontological reduction, this procedural recommendation does not follow directly from it. In fact, unlike the idea The philosophical study of the notion and possibility of reduction links up of ontological reduction, methodological reductionism can be quite with several core issues in the philosophy of science. As reduction controversial. It has been argued that exclusively reductionistic research involves relating (broadly speaking) one “body of scientific knowledge” strategies can be systematically biased so as to overlook salient biological to another, it presupposes an account of what the relevant epistemic units features, and that for certain questions a more fruitful methodology to be related are—theories, laws, models, concepts, or disciplines—and consists in integrating the discovery of molecular causes with the how they should be understood. Since the reduction of one theory to investigation of higher level features (Wimsatt 1980).[1] another is usually presumed to mean that somehow the reducing theory explains the principles of the reduced theory, reduction is also related to (iii) Epistemic reduction is the idea that the knowledge about one the issue of scientific explanation. For example, if a more fundamental scientific domain (typically about higher level processes) can be reduced theory fully reduces another theory or even reduces several theories, to another body of scientific knowledge (typically concerning a lower and unification (of some sort) results. The situation where a historically earlier more fundamental level). While an endorsement of some form of theory is reduced to a later theory is an intuitive case in which scientific epistemic reduction can be motivated by ontological reduction combined progress might occur. Since arguments against the existence of this type with methodological reductionism (e.g., the past success of reductionistic of reduction have maintained that terms occurring in both the precursor research in biology), the possibility of epistemic reduction does not and descendant theory have different meanings (“incommensurability”), follow from the conjunction of ontological and methodological reduction. reduction also relates to the issue of the meaning of scientific terms and Indeed, debates about reduction in the philosophy of biology have conceptual change. Therefore, accounts of reduction depend on centered on this third type of reduction as the most controversial issue commitments made about other, coordinating notions and their adequacy (see Section 4). Our discussion will therefore focus primarily on issues depends in many cases on these related philosophical commitments. This related to epistemic reduction. Prior to evaluating any reduction of one has led some philosophers to pursue an account of reduction in biology body of knowledge to another, a conception of those bodies of knowledge that is as uncommitted as