There has recently been controversy over the existence of 'multiple realization' in addition to some confusion between different conceptions of its nature. To resolve these problems, we focus on concrete examples from the sciences to provide precise accounts of the scientific concepts of 'realization' and 'multiple realization' that have played key roles in recent debates in the philosophy of science and philosophy of psychology. We illustrate the advantages of our view over a prominent rival account (...) ( Shapiro, 2000 and 2004 ) and use our work to rebut recent objections to the long-standing claim that psychological properties are multiply realized. For we use scientific evidence, in combination with our more precise theoretical framework, to show that we have strong reason to believe that psychological properties are indeed multiply realized both at the biochemical and neuronal levels. (shrink)

Multiple realizability has been at the heart of debates about whether the mind reduces to the brain, or whether the items of a special science reduce to the items of a physical science. I analyze the two central notions implied by the concept of multiple realizability: "multiplicity," otherwise known as property variability, and "realizability." Beginning with the latter, I distinguish three broad conceptual traditions. The Mathematical Tradition equates realization with a form of mapping between objects. Generally speaking, (...) x realizes (or is the realization of) y because elements of y map onto elements of x. The Logico-Semantic Tradition translates realization into a kind of intentional or semantic notion. Generally speaking, x realizes (or is the realization of) a term or concept y because x can be interpreted to meet the conditions for satisfying y. The Metaphysical Tradition views realization as a species of determination between objects. Generally speaking, x realizes (or is the realization of) y because x brings about or determines y. I then turn to the subject of property variability and define it in a formal way. I then conclude by discussing some debates over property identity and scientific theory reduction where the resulting notion of multiple realizability has played a central role, for example, whether the nonreductive consequences of multiple realizability can be circumvented by scientific theories framed in terms of narrow domain-specific properties, or wide disjunctive properties. (shrink)

Multiple realizability says that the same kind of mental states may be manifested by systems with very different physical constitutions. Putnam ( 1967 ) supposed it to be “overwhelmingly probable” that there exist psychological properties with different physical realizations in different creatures. But because function constrains possible physical realizers, this empirical bet is far less favorable than it might initially have seemed, especially when we take on board the richer picture of neural and brain function that neuroscience has been (...) uncovering over the past forty years, in which all sorts of brain activities play crucial roles beyond all-or-nothing electrical signaling. Because of its evolutionary history, the brain’s metabolic and informational processes are inextricably intertwined. The resulting complex integrated functions impose more constraints on possible realizers than the clean, single-purpose functions usually cited as examples in discussions of multiple realizability—with ramifications for the functionalist and computationalist foundations of cognitive science, artificial intelligence, and the philosophy of mind. (shrink)

Since Hilary Putnam offered multiple realization as an empirical hypothesis in the 1960s, philosophical consensus has turned against the idea that mental processes are identifiable with brain processes, and multiple realization has become the keystone of the 'antireductive consensus' across philosophy of science. Thomas W. Polger and Lawrence A. Shapiro offer the first book-length investigation of multiple realization, which serves as a starting point to a series of philosophically sophisticated and empirically informed arguments that (...) cast doubt on the generality of multiple realization in the cognitive sciences. They argue that mind-brain identities have played an important role in the growth and achievements of the cognitive sciences, and suggest that there is little prospect for multiple realization in an empirically-based theory of mind. This leads Polger and Shapiro to offer an alternative framework for understanding explanations in the cognitive sciences, as well as in chemistry, biology, and other non-basic sciences. (shrink)

Multiple realization was once taken to be a challenge to reductionist visions, especially within cognitive science, and a foundation of the “antireductionist consensus.” More recently, multiple realization has come to be challenged on naturalistic grounds, as well as on more “metaphysical” grounds. Within cognitive science, one focal issue concerns the role of neural plasticity for addressing these issues. If reorganization maintains the same cognitive functions, that supports claims for multiple realization. I take up the (...) reorganization involved in language dysfunctions to deal with questions concerned with multiple realization and neural plasticity. Beginning with Broca’s case for localization and the nineteenth century discussion of “reorganization,” and returning to more recent evidence for neural plasticity, I argue that, in the end, there is substantial support for multiple realization in cognitive systems; I further argue that this is wholly consistent with a recognition of methodological pluralism in cognitive science. (shrink)

Multiply realizable properties are those whose realizers are physically diverse. It is often argued that theories which contain them are ipso facto irreducible. These arguments assume that physical explanations are restricted to the most specific descriptions possible of physical entities. This assumption is descriptively false, and philosophically unmotivated. I argue that it is a holdover from the late positivist axiomatic view of theories. A semantic view of theories, by contrast, correctly allows scientific explanations to be couched in the most perspicuous, (...) powerful language available. On a semantic view, traditional notions of multiple realizability are thus very hard to motivate. At best, one must abandon either the idea that multiple realizability is an interesting scientific notion, or else admit that multiply realizable properties do not automatically block scientific reductions. (shrink)

The claim of the multiple realizability of mental states by brain states has been a major feature of the dominant philosophy of mind of the late 20th century. The claim is usually motivated by evidence that mental states are multiply realized, both within humans and between humans and other species. We challenge this contention by focusing on how neuroscientists differentiate brain areas. The fact that they rely centrally on psychological measures in mapping the brain and do so in a (...) comparative fashion undercuts the likelihood that, at least within organic life forms, we are likely to find cases of multiply realized psychological functions. (shrink)

One way that scientifically recognized properties are multiply realized is by “compensatory differences” among realizing properties. If a property G is jointly realized by two properties F1 and F2, then G can be multiply realized by having changes in the property F1 offset changes in the property F2. In some cases, there are scientific laws that articulate how distinct combinations of physical quantities can determine one and the same value of some other physical quantity. One moral to draw is that (...) in such cases we have the multiple realization of a single determinate, “fine grained” property instance that is exactly similar to another instance. As simple as this moral is, it has ramifications for a number of recent discussions of multiple realization in science. Taken collectively, these ramifications indicate that multiple realization by compensatory adjustments merits greater attention in the philosophy of science literature than it has hitherto received. (shrink)

This paper concerns what Jerry Fodor calls a 'metaphysical mystery': How can there by macroregularities that are realized by wildly heterogeneous lower level mechanisms? But the answer to this question is not as mysterious as many, including Jaegwon Kim, Ned Block, and Jerry Fodor might think. The multiple realizability of the properties of the special sciences such as psychology is best understood as a kind of universality, where 'universality' is used in the technical sense one finds in the physics (...) literature. It is argued that the same explanatory strategy used by physicists to provide understanding of universal behavior in physics can be used to explain how special science properties can be heterogeneously multiply realized. (shrink)

The past two decades have witnessed a revival of interest in multiple realization and multiply realized kinds. Bechtel and Mundale’s (1999) illuminating discussion of the subject must no doubt be credited with having generated much of this renewed interest. Among other virtues, their paper expresses what seems to be an important insight about multiple realization: that unless we keep a consistent grain across realized and realizing kinds, claims alleging the multiple realization of psychological kinds (...) are vulnerable to refutation. In this paper I argue that, intuitions notwithstanding, the terms of their recommendation make it impossible to follow, while also misleadingly insinuating that its application virtually guarantees mind-brain identity. Instead of a matching of grains, what multiple realization really requires is a principled method for adjudicating upon differences between tokens. Shapiro’s (2000) work on multiple realization can be understood as an attempt to adumbrate just such a method. While his “causal relevance” criterion can easily be mistaken for Bechtel and Mundale’s grain requirement, my analysis reveals exactly where and why these two tests diverge. (shrink)

Reductionism is often understood to include two theses: (1) every singular occurrence that the special sciences can explain also can be explained by physics; (2) every law in a higher-level science can be explained by physics. These claims are widely supposed to have been refuted by the multiple realizability argument, formulated by Putnam (1967, 1975) and Fodor (1968, 1975). The present paper criticizes the argument and identifies a reductionistic thesis that follows from one of the argument's premises.

In the literature on multiple realizability and the identity theory, cases of neural plasticity have enjoyed a very limited role. The present article attempts to remedy this small influence by arguing that clinical and experimental evidence of quite extensive neural reorganization offers compelling support for the claim that psychological kinds are multiply realized in neurological kinds, thus undermining the identity theory. In particular, cases are presented where subjects with no measurable psychological deficits also have vast, though gradually received, neurological (...) damage. Common objections and concerns are also discussed and rejected. 1 Introduction2 The GRP, Serial Lesion Effect, and Multiple Realizability2.1 A case study of the serial lesion effect2.2 Evaluating the case study’s evidence for multiple realizability3 The GRP More Generally4 Objections to the GRP as Evidence for Multiple Realizability4.1 Small plastic effects and neurological taxonomies4.2 But do neural regions and locations even matter at all?4.3 But are there not other options besides location?5 Conclusion. (shrink)

Multiple realization occurs when a natural kind is variably realized at more basic levels and the common physical structure of the realizers is not essential for supporting nomological statements. It has been suggested that this phenomenon may be an outcome of natural selection acting over multiple realizers that perform an adaptive function. In this paper, we make the following contributions. First, we present a revision of this model, characterized by stricter equilibrium conditions and superior explanatory power. Second, (...) we present a typology of multiple realization that provides a plausible account of the differences between across- and within-species multiple realization. Third, we perform a formal analysis of the dynamics of multiple realization that sheds light on the differences between multiple realization at different levels of organization. (shrink)

This paper focuses on the framework for the compositional relations of properties in the sciences, or "realization relations", offered by Ken Aizawa and Carl Gillett (A&G) in a series of papers, and in particular on the analysis of "multiple realizations" they build upon it. I argue that A&G's analysis of multiple realization requires an account of levels and I try to show, then, that the A&G framework is not successful under any of the extant accounts of (...) levels. There is consequently a real concern tha thte A&G framework for realization may not be viable. (shrink)

We critically analyze Alexander Rosenberg’s argument based on the multiple realizability of biological properties that there are no biological laws. The argument is intuitive and suggestive. Nevertheless, a closer analysis reveals that the argument rests on dubious assumptions about the nature of natural selection, laws of nature, and multiple realizability. We also argue that the argument is limited in scope, since it applies to an outmoded account of laws and the applicability of the argument to other more promising (...) accounts of laws is questionable. Another concern of ours is that the relation between multiple realizability and natural selection is more complex than Rosenberg acknowledges. Finally, we claim that an explanation for why Rosenberg’s argument appears persuasive and appealing is that the argument is based on an inflated concept of multiple realizability that rests on unreliable intuitions concerning what counts as a different realization of the same property. Consequently, we argue that the argument is at best inconclusive and at worst false insofar as its implications for the existence of biological laws are concerned. (shrink)

This article examines the multiple realizability thesis within a causal framework. The beginnings of this framework are found in Elliott Sober’s “Multiple Realizability Argument against Reduction,”...

This chapter attempts to vindicate what is sometimes pilloried as the “Received View” of realization and multiple realization in the philosophy of mind. Using the Dimensioned view of realization, it proceeds to give three “mechanistic” accounts of how multiple realization is possible. There is what might be called multiple realization with individual variation, multiple realization by compensatory differences, and multiple realization by orthogonal realizers. It, then, shows how this (...) multiple realization leads to a kind of autonomy of psychology, while nonetheless integrating neuroscience and psychology. It also shows how one might avoid “Keeley’s Dilemma” regarding the relationship between neuroscience and psychology. (shrink)

Must a theory of quantum gravity have some truth to it if it can recover general relativity in some limit of the theory? This paper answers this question in the negative by indicating that general relativity is multiply realizable in quantum gravity. The argument is inspired by spacetime functionalism—multiple realizability being a central tenet of functionalism—and proceeds via three case studies: induced gravity, thermodynamic gravity, and entanglement gravity. In these, general relativity in the form of the Einstein field equations (...) can be recovered from elements that are either manifestly multiply realizable or at least of the generic nature that is suggestive of functions. If general relativity, as argued here, can inherit this multiple realizability, then a theory of quantum gravity can recover general relativity while being completely wrong about the posited microstructure. As a consequence, the recovery of general relativity cannot serve as the ultimate arbiter that decides which theory of quantum gravity that is worthy of pursuit, even though it is of course not irrelevant either qua quantum gravity. Thus, the recovery of general relativity in string theory, for instance, does not guarantee that the stringy account of the world is on the right track; despite sentiments to the contrary among string theorists. (shrink)

In recent decades, a number of authors have relied on the multiple realizability argument to reject methodological individualism. In this article, I argue that this strategy results in serious difficulties and makes it impossible to identify social entities and phenomena.

Arguments for multiple realization depend on the idea that the same kind of function is realized by different kinds of structures. It is important to such arguments that we know the kinds used in the arguments have been individuated properly. In the philosophical literature, though, claims about how to individuate kinds are frequently decided on intuitive grounds. This paper criticizes this way of approaching kinds by considering how practicing researchers think about the matter. I will consider several examples (...) in which the practice of researchers on comparative vision conflicts with the standard account of these issues. (shrink)

Multiple realization has traditionally been characterized as a thesis about the relation between kinds posited by the taxonomic systems of different sciences. In this paper, I argue that there are good reasons to move beyond this framing. I begin by showing how the traditional framing is tied to positivist models of explanation and reduction and proceed to develop an alternate framing that operates instead within causal explanatory frameworks. I draw connections between this account and the notion of functional (...) robustness in biology and neuroscience. I then examine two cases from systems neuroscience that substantiate my account and show how traditional debates fail to track important features of these cases. (shrink)

It has often been thought that compositional variation across systems that are similar from the point of view of the special sciences provides a key point in favor of the multiple realization of special science kinds and in turn the broadly nonreductive consequences often thought to follow from multiple realization. Yet in a series of articles, and culminating in The Multiple Realization Book, Tom Polger and Larry Shapiro argue that an account of multiple (...) realization demanding enough to yield such nonreductive consequences implies that compositional variation is far less significant for the multiple realization of special science kinds than many have supposed. I argue, in contrast, that even on this demanding account, lower-level compositional variation may frequently support the multiple realization of special science kinds across the systems of interest, and that there is a good explanation for where Polger and Shapiro go wrong in drawing the contrary conclusion. I consider but reject Carl Gillett’s claim that different views about the significance of compositional variation for multiple realization phenomena should be traced to implicit disagreement about the metaphysics of realization. (shrink)

The multiple-realizability argument has been the mainstay ofanti-reductionist consensus in philosophy of mind for the past thirty years. Reductionist opposition to it has sometimes taken the form of the Disjunctive Move: If mental types are multiply-realizable, they are not coextensive with physical types; they might nevertheless be coextensive with disjunctionsof physical types, and those disjunctions could still underwrite psychophysical reduction. Among anti-reductionists, confidence is high that the Disjunctive Move fails; arguments to this effect, however, often leave something to be (...) desired. I raise difficulties for one anti-reductionist response to the DisjunctiveMove, the Explanatory Response. (shrink)

Multiple realizability (MR) is traditionally conceived of as the feature of computational systems, and has been used to argue for irreducibility of higher-level theories. I will show that there are several ways a computational system may be seen to display MR. These ways correspond to (at least) five ways one can conceive of the function of the physical computational system. However, they do not match common intuitions about MR. I show that MR is deeply interest-related, and for this reason, (...) difficult to pin down exactly. I claim that MR is of little importance for defending computationalism, and argue that it should rather appeal to organizational invariance or substrate neutrality of computation, which are much more intuitive but cannot support strong antireductionist arguments. (shrink)

b>: This article explains the concept of multiple realizability and its role in the philosophy of mind. In particular, I consider what is required for the multiple realizability of psychological kinds, the relevance of multiple realizability to the reducibility and autonomy of psychology, as well as further refinements of the concept that would prove helpful.

Framed within the dialectic of the causal exclusion argument (Kim 2005), this paper does two things. One, it clarifies some properties of multiple realizability based on its true origin (Turing 1950). And two, it challenges a form of argument Noordhof (1997), Clarke (1999), and Whittle (2007) employ to support the idea that the mental has causal powers not had by its physical realization base (Novel). The paper challenges Novel with ideas derived from multiple realizability, among others.

Bechtel and Mundale (1999) argue that multiple realizability is not plausible. They point out that neuroscientists assume that psychological traits are realized similarly in homologous brain structures and contend that a biological aspect of the brain that is relevant to neuropsychological state individuation provides evidence against multiple realizability. I argue that Bechtel and Mundale adduce the wrong sort of evidence against multiple realizability. Homologous traits do not provide relevant evidence. It is homoplasious traits of brains that can (...) provide evidence for or against multiple realizability. (shrink)

Critics of multiple realizability have recently argued that we should concentrate solely on actual here-and-now realizations that are found in nature. The possibility of alternative, but unactualized, realizations is regarded as uninteresting because it is taken to be a question of pure logic or an unverifiable scenario of science fiction. However, in the biological context only a contingent set of realizations is actualized. Drawing on recent work on the theory of neutral biological spaces, the paper shows that we can (...) have ways of assessing the modal dimension of multiple realizability that do not have to rely on mere conceivability. (shrink)

The argument from multiple realizability is that, because quite diverse physical systems are capable of giving rise to identical psychological phenomena, mental states cannot be reduced to physical states. This influential argument depends upon a theory of reduction that has been defunct in the philosophy of science for at least fifteen years. Better theories are now available.

The ?Dimensioned? view analyzes (multiple) realization in terms of compositional relation, and the ?Flat? view analyzes (multiple) realization in terms of causal-functional mechanism. The two different analyses of realization lead to the disagreement about whether realization is transitive. The two views, perhaps not surprisingly, have different consequences on testing for multiple realization, and prescribe different ?reconstructions? for the evidential significance of observation for multiple realization. I examine the differences between the (...) two views on testing for multiple realization within a model-selection theoretical framework. I claim that the model-selection theoretical framework provides a ground to discuss and assess evidence for multiple realization. (shrink)

Consider what the brain-state theorist has to do to make good his claims. He has to specify a physical–chemical state such that any organism (not just a mammal) is in pain if and only if (a) it possesses a brain of suitable physical–chemical structure; and (b) its brain is in that physical–chemical state. This means that the physical–chemical state in question must be a possible state of a mammalian brain, a reptilian brain, a mollusc’s brain (octopuses are mollusca, and certainly (...) feel pain), etc. At the same time, it must not be a possible (physically possible) state of the brain of any physically possible creature that cannot feel pain. Even if such a state can be found, it must be nomologically certain that it will also be a state of the brain of any extraterrestrial life that may be found that will be capable of feeling pain before we can even entertain the supposition that it may be pain. It is not altogether impossible that such a state will be found... . But this is certainly an ambitious hypothesis. (Putnam 1967/1975, p. 436) The belief that mental states are multiply realized is now nearly universal among philosophers, as is the belief that this fact decisively refutes the identity theory. I argue that the empirical support for multiple realization does not justify the confidence that has been placed in it. In order for multiple realization of mental states to be an objection to the identity theory, the neurological differences among pains, for example, must be such as to guarantee that they are of distinct neurological kinds. But the phenomena traditionally cited do not provide evidence of that sort of variation. In particular, examples of neural plasticity do not provide such evidence. (shrink)

The claim of the multiple realizability of mental states by brain states has been a major feature of the dominant philosophy of mind of the late 20th century. The claim is usually motivated by evidence that mental states are multiply realized, both within humans and between humans and other species. We challenge this contention by focusing on how neuroscientists differentiate brain areas. The fact that they rely centrally on psychological measures in mapping the brain and do so in a (...) comparative fashion undercuts the likelihood that, at least within organic life forms, we are likely to find cases of multiply realized psychological functions. (shrink)

The paper criticizes standard functionalist arguments for multiple realization. It focuses on arguments in which psychological states are conceived as computational, which is precisely where the multiple realization doctrine has seemed the strongest. It is argued that a type-type identity thesis between computational states and physical states is no less plausible than a multiple realization thesis. The paper also presents, more tentatively, positive arguments for a picture of local reduction.

The multiple-realizability argument has been the mainstay of anti-reductionist consensus in philosophy of mind for the past thirty years. Reductionist opposition to it has sometimes taken the form of the Disjunctive Move: If mental types are multiply-realizable, they are not coextensive with physical types; they might nevertheless be coextensive with disjunctions of physical types, and those disjunctions could still underwrite psychophysical reduction. Among anti-reductionists, confidence is high that the Disjunctive Move fails; arguments to this effect, however, often leave something (...) to be desired. I raise difficulties for one anti-reductionist response to the Disjunctive Move, the Explanatory Response. (shrink)

Multiple Realizability (MR) must still be regarded as one of the principal arguments against type reductionist accounts of higher-order properties and their special laws. Against this I argue that there is no unique MR but rather a multitude of MR categories. In a slogan: MR is itself “multi-realized”. If this is true then we cannot expect one unique reductionist strategy against MR as an anti-reductionist argument. The main task is rather to develop a taxonomy of the wide variety of (...) MR cases and to sketch possible reductionist answers for each class of cases. The paper outlines some first steps in this direction. (shrink)

One might have thought that if something has two or more distinct realizations, then that thing is multiply realized. Nevertheless, some philosophers have claimed that two or more distinct realizations do not amount to multiple realization, unless those distinct realizations amount to multiple “ways” of realizing the thing. Corey Maley, Gualtiero Piccinini, Thomas Polger, and Lawrence Shapiro are among these philosophers. Unfortunately, they do not explain why multiple realization requires multiple “ways” of realizing. More (...) significantly, their efforts to articulate multiple “ways” of realizing turn out to be problematic. (shrink)

According to a popular ‘explanationist’ argument for moral or mathematical realism the best explanation of some phenomena are moral or mathematical, and this implies the relevant form of realism. One popular way to resist the premiss of such arguments is to hold that any supposed explanation provided by moral or mathematical properties is in fact provided only by the non-moral or non-mathematical grounds of those properties. Many realists have responded to this objection by urging that the explanations provided by the (...) higher-level, moral and mathematical, properties are informative in a way in which their supposed replacements are not, and that this is because moral and mathematical properties are multiply realizable. This chapter responds to this manoeuvre by proposing a way in which moral and mathematical explanations might preserve the distinctive import that multiple realizability brings, without committing those who accept them to the existence of moral and mathematical properties. (shrink)

In his latest book Physicalism, or Something near Enough, Jaegwon Kim argues that his version of functional reductionism is the most promising way for saving mental causation. I argue, on the other hand, that there is an internal tension in his position: Functional reductionism does not save mental causation if Kim’s own supervenience argument is sound. My line of reasoning has the following steps: (1) I discuss the supervenience argument and I explain how it motivates Kim’s functional reductionism; (2) I (...) present what I call immense multiple realization, which says that macro-properties are immensely multiply realized in determinate micro-based properties; (3) on that background I argue that functional reductionism leads to a specified kind of irrealism for mental properties. Assuming that such irrealism is part of Kim’s view, which Kim himself seems to acknowledge, I argue that Kim’s position gets the counterfactual dependencies between macro-causal relata wrong. Consequently, his position does not give a conservative account of mental causation. I end the paper by discussing some alternative moves that Kim seems to find viable in his latest book. I argue on the assumption that the supervenience argument is sound, so the discussion provides further reasons to critically reevaluate that argument because it generalizes in deeply problematic ways. (shrink)

It has been debated what implications multiple realizability has for reductionism. I claim that more explicit attention needs to be paid to the distinction between multiple realizations of kinds and diverse implementations of laws. In this paper, I distinguish two different theses on the relations between multiple realization and diverse implementation: one thesis states that multiple realizations imply diverse implementations and the other states the converse. I claim that although antireductionism might turn out to be (...) false if the first thesis is accepted, this “realization‐based” antireductionism is not the only option for antireductionism. For the antireductionists who accept the second thesis, multiple realizations only provide evidence for diverse implementations. I defend this “implementation‐based” antireductionism again Shapiro's dilemma. I argue that one horn of the dilemma does not pose any problem and that the other horn simply begs the question. (shrink)

Over the last 25 years, there has been a concerted effort to settle questions about multiple realization by bringing detailed scientific evidence to bear. Ken Aizawa and Carl Gillett have pursued this scientific approach to multiple realization with a precise theory and applications. This paper reviews the application of the Dimensioned approach to human color vision, addressing objections that have appeared in the literature.

Multiple realizability (MR) is not necessarily unclear nor does it purely operate at the computational level. To understand potential relationships between MR and other constraints, such as metabolic, we formalise possible meanings of function in cognitive science. We build on these to formalise MR, thus resolving its apparent vagaries. Importantly, MR formalisms meaningfully guide and constrain theory building.

Thomas Polger and Lawrence Shapiro claim that unlike human-made artifacts cases of multiple realization in naturally occurring systems are uncommon. Drawing on cases from systems biology, I argue t...

Polger and Shapiro argue that their official recipe, a criterion for judging when the phenomenon of multiple realization exists, renders MR less widespread than its proponents have assumed. I argue that, although Polger and Shapiro’s criterion is a useful contribution, they arrive at their conclusion too hastily. Contrary to Polger and Shapiro, I claim that the phenomenon of multiple realization in the biological world, judged by their criterion, is not as scarce as they suggest. To show (...) this, an updated official recipe, namely a multiple mechanistic realization thesis, integrating Polger and Shapiro’s criterion with a compositional conception of realization, is developed. Then, three examples of varied kinds are examined, showing that cases of MR are not so hard to find in the biological world. (shrink)

A common view is that the truth of multiple realization—e.g., about psychological states—entails the truth of functionalism. This is supposed to follow because what is multiply realized is eo ipso realized. I argue that view is mistaken by demonstrating how it misrepresents arguments from multiple realization. In particular, it undermines the empirical component of the arguments, and renders the multiplicity of the realization irrelevant. I suggest an alternative reading of multiple realizability arguments, particularly in (...) philosophy of psychology. And I explain the proper way to understand the relation between realization and multiple realization. (shrink)

Multiple realization historically mandated the autonomy of psychology, and its principled irreducibility to neuroscience. Recently, multiple realization and its implications for the reducibility of psychology to neuroscience have been challenged. One challenge concerns the proper understanding of reduction. Another concerns whether multiple realization is as pervasive as is alleged. I focus on the latter question. I illustrate multiple realization with actual, rather than hypothetical, cases of multiple realization from within the (...) biological sciences. Though they do support a degree of autonomy for higher levels of explanation and organization, they do not have the dire consequences critics of multiple realization fear. †To contact the author, please write to: Department of Philosophy, University of Cincinnati, P.O. Box 210374, Cincinnati, OH 45221‐0374; e‐mail: [email protected]. (shrink)

Arguing about the types and tokens of neuroscience and psychology has provided philosophical sport for decades. Type, or strong identity theory, was the target of Putnam’s original multiple realizability (MR) argument and asserts that because mental types are multiply realized by several different physical types, no lawlike identity relation between mental and physical types exists. Both psychology and neuroscience have made rapid progress in the intervening years, allowing for more empirically-guided ways of exploring their mutual explanatory value to each (...) other. I briefly discuss the historical impact of MR, offer a diagnosis of its endurance, and revisit an earlier position I co-authored with William Bechtel. I then consider MR in light of neuroplasticity and localization, both commonly taken to support the MR argument. I argue that these not only fail in this support, but instead, show the advantage of a more empirically-grounded approach based on structure–function relationships. In this light, MR itself may even be regarded as a kind of neuro-psychological discovery principle; discovering a function that appears to be subserved by multiple neuromechanisms may point us toward interesting commonalities, rather than differences, of neurological structure. (shrink)

Recently, several critics of the multiple realizability thesis have argued that philosophers have tended to accept the thesis on too weak grounds. On the one hand, the analytic challenge has problematized how philosophers have treated the multiple realization relation itself, claiming that assessment of the sameness of function and the relevant difference of realizers has been uncritical. On the other hand, it is argued that the purported evidence of the thesis is often left empirically unverified. This paper (...) provides a novel strategy to answer these worries by introducing a role for multiple realizability in the context of biological engineering. In the field of synthetic biology, bioengineers redesign the evolutionary realizations of biological functions, even constructing artificial chemical surrogates in the laboratory. I show how in the rational design approach to biological engineering, multiple realizability can function as a design heuristic in which the sameness of function and difference of realizers can be controlled. Although practically motivated, this engineering approach has also a theoretical, exploratory component that can be used to study the empirical limitations of multiple realizability. Successful realization of the engineering designs would amount to a concrete demonstration of multiple realizability, taking evidence for MRT beyond what is readily found in nature. (shrink)