Functional Realization

“Realization” is a technical term that is used by metaphysicians, philosophers of mind, and philosophers of science to denote some dependence relation that is thought to obtain between higher-level properties and lower-level properties. It is said that mental properties are realized by physical properties; functional and computational properties are realized by first-order properties that occupy certain causal/functional roles; dispositional properties are realized by categorical properties; so on and so forth. Given this wide usage of the term “realization”, it would be (...) right to think that there might be different dependence relations that this term denotes in different cases. Any relation that is aptly picked out by this term can be taken to be a realization relation. The aim of this state-of-the-field article is to introduce the central questions about the concept of realization, and provide formulations of a number of realization relations. In doing so, I identify some theoretical roles realization relations should play, and discuss some theories of realization in relation to these theoretical roles. (shrink)

Hilary Putnam has argued that computational functionalism cannot serve as a foundation for the study of the mind, as every ordinary open physical system implements every finite-state automaton. I argue that Putnam's argument fails, but that it points out the need for a better understanding of the bridge between the theory of computation and the theory of physical systems: the relation of implementation. It also raises questions about the class of automata that can serve as a basis for understanding the (...) mind. I develop an account of implementation, linked to an appropriate class of automata, such that the requirement that a system implement a given automaton places a very strong constraint on the system. This clears the way for computation to play a central role in the analysis of mind. (shrink)

To clarify the notion of computation and its role in cognitive science, we need an account of implementation, the nexus between abstract computations and physical systems. I provide such an account, based on the idea that a physical system implements a computation if the causal structure of the system mirrors the formal structure of the computation. The account is developed for the class of combinatorial-state automata, but is sufficiently general to cover all other discrete computational formalisms. The implementation relation is (...) non-vacuous, so that criticisms by Searle and others fail. This account of computation can be extended to justify the foundational role of computation in artificial intelligence and cognitive science. (shrink)

Many areas of science develop by discovering mechanisms and role functions. Cummins' (1975) analysis of role functions-according to which an item's role function is a capacity of that item that appears in an analytic explanation of the capacity of some containing system-captures one important sense of "function" in the biological sciences and elsewhere. Here I synthesize Cummins' account with recent work on mechanisms and causal/mechanical explanation. The synthesis produces an analysis of specifically mechanistic role functions, one that uses the characteristic (...) active, spatial, temporal, and hierarchical organization of mechanisms to add precision and content to Cummins' original suggestion. This synthesis also shows why the discovery of role functions is a scientific achievement. Discovering a role function (i) contributes to the interlevel integration of multilevel mechanisms, and (ii) provides a unique, contextual variety of causal/mechanical explanation. (shrink)

I use Carl Gillett’s much heralded dimensioned theory of realization as a platform to develop a plausible part–whole theory. I begin with some basic desiderata for a theory of realization that its key terms should be defined and that it should be explanatory. I then argue that Gillett’s original theory violates these conditions because its explanatory force rests upon an unspecified “in virtue of” relation. I then examine Gillett’s later version that appeals instead to theoretical terms tied to “mechanisms.” Yet (...) I argue that it too violates the desiderata, since it defines realization for mechanisms in terms of two undefined ideas whose explanatory credentials have not been established—“implementation” and “grounds.” Thus I drop those ideas in favor of an explicit constraint that the parts and properties provide a mechanistic explanation. I also distinguish a special mechanistic theory from a preferred general theory that incorporates other kinds of part–whole explanations that target causal powers or capacities. The result is a theory that has the explanatory virtues of mechanistic theories as well as a broader scope desired by Gillett. I also compare the result to a similar idea from Robert Cummins that has been neglected in recent discussions of realization, namely, his general property analysis rather than his functional analysis. Finally, I defend the preferred general theory against possible objections that attempt to show a conflict between metaphysical demands on a theory of realization versus facts about good scientific explanation. (shrink)

There is currently a significant amount of interest in understanding and developing theories of realization. Naturally arguments have arisen about the adequacy of some theories over others. Many of these arguments have a point. But some can be resolved by seeing that the theories of realization in question are not genuine competitors because they fall under different conceptual traditions with different but compatible goals. I will first describe three different conceptual traditions of realization that are implicated by the arguments under (...) discussion. I will then examine the arguments, from an older complaint by Norman Malcolm against a familiar functional theory to a recent argument by Thomas Polger against an assortment of theories that traffic in inherited causal powers, showing how they can be resolved by situating the theories under their respective conceptual traditions. (shrink)

I resolve an argument over “flat” versus “dimensioned” theories of realization. The theories concern, in part, whether realized and realizing properties are instantiated by the same individual (the flat theory) or different individuals in a part-whole relationship (the dimensioned theory). Carl Gillett has argued that the two views conflict, and that flat theories should be rejected on grounds that they fail to capture scientific cases involving a dimensioned relation between individuals and their constituent parts. I argue on the contrary that (...) the two types of theory complement one another, even on the same range of scientific cases. I illustrate the point with two popular functionalist versions of flat and dimensioned positions – causal-role functionalism and a functional analysis by decomposition – that combine into a larger picture I call “comprehensive functional realization.” I also respond to some possible objections to this synthesis of functionalist views. (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)

Melnyk provides a rigorous analysis of the notion of realization with the aim of defining Physicalism. It is argued here that contrary to Melnyk's Realization Physicalism, the idea that mental phenomena are realized by physical phenomena fails to capture the physicalist belief that the former obtain in virtue of the latter. The conclusion is not that Physicalism is false, but that its truth is best explained with some notion other than realization in Melnyk's sense. I also argue that the problems (...) with Melnyk's brand of Realization Physicalism generalize to other potential attempts to express Physicalism in terms of realization. The burden of proof is on the Realization Physicalist to show that physicalist intuitions can be adequately captured with the notion of realization. (shrink)

The notion of realization is defined so that we can better understand what it means to say that mentality is physically realized. It is generally thought that physical properties realize mental properties (thesis PR). The definitions provided here support this belief, but they also reveal that mental properties can be viewed as realizing physical properties. This consequence questions the value of PR in helping us capture the idea that mental phenomena are dependent upon (i.e., obtain by virtue of) physical phenomena. (...) In particular, Kim's functional model of reduction and Melnyk's functional definition of physicalism are refuted. (shrink)

Several philosophers (e.g., Ehring (Nous (Detroit, Mich.) 30:461–480, 1996 ); Funkhouser (Nous (Detroit, Mich.) 40:548–569, 2006 ); Walter (Canadian Journal of Philosophy 37:217–244, 2007 ) have argued that there are metaphysical differences between the determinable-determinate relation and the realization relation between mental and physical properties. Others have challenged this claim (e.g., Wilson (Philosophical Studies, 2009 ). In this paper, I argue that there are indeed such differences and propose a “mechanistic” account of realization that elucidates why these differences hold. This (...) account of realization incorporates two distinct roles that mechanisms play in the realization of mental (and other special science) properties which are implicit, but undeveloped, in the literature—what I call “constitutive” and “integrative” mechanisms. I then use these two notions of mechanism to clarify some debates about the relations between realization, multiple realizability, and irreducibility. (shrink)

The realization relation is commonly explicated via, or identified with, the causal role playing relation. However, the realization relation does not formally match the causal role playing relation. While realization is a relation between a base realizer property and a single higher level realized property, I argue that the causal role playing relation as typically defined is a relation between a base property and two higher-level role properties. Advocates of using causal role playing to explicate realization must therefore decide which (...) of the two kinds of role property they identify with realized properties; I argue that neither choice is good, and the fact that one must make a choice is worse. A search for a new way of defining realization is in order. (shrink)

This book, based on Jaegwon Kim's 1996 Townsend Lectures, presents the philosopher's current views on a variety of issues in the metaphysics of the mind...

In this wide-ranging study, Levine explores both sides of the mind-body dilemma, presenting the first book-length treatment of his highly influential ideas on the How does one explain the physical nature of an experience? This puzzle, the "explanatory gap" between mind and body, is the focus of this work by an influential scholar in the field.

In this book, William Lycan reviews the diverse philosophical views on consciousness--including those of Kripke, Block, Campbell, Sellars, and Casteneda--and ..

The concept of mechanism is analyzed in terms of entities and activities, organized such that they are productive of regular changes. Examples show how mechanisms work in neurobiology and molecular biology. Thinking in terms of mechanisms provides a new framework for addressing many traditional philosophical issues: causality, laws, explanation, reduction, and scientific change.

In earlier work, I proposed and defended a formulation of physicalism that was distinctive in appealing to a carefully-defined relation of physical realization. Various philosophers have since presented challenges to this formulation. In the present paper, I aim to show that these challenges can be overcome.

Can physicalism (or materialism) be non-reductive? I provide an opinionated survey of the debate on this question. I suggest that attempts to formulate non-reductive physicalism by appeal to claims of event identity, supervenience, or realization have produced doctrines that fail either to be physicalist or to be non-reductive. Then I treat in more detail a recent attempt to formulate non-reductive physicalism by Derk Pereboom, but argue that it fares no better.

The paper argues that a broadly functionalist picture of psychological phenomena is quite consistent with at least one interesting thesis of psychological reductionism.

Twenty years ago, Richard Boyd suggested that physicalism could be formulated by appeal to a notion of realization, with no appeal to the identity of the non-physical with the physical. In (Melnyk 2003), I developed this suggestion at length, on the basis of one particular account of realization. I now ask what happens if you try to formulate physicalism on the basis of other accounts of realization, accounts due to LePore and Loewer and to Shoemaker. Having explored two new formulations (...) of physicalism, I conclude that my 2003 formulation remains the most promising. (shrink)

A Physicalist Manifesto is a full treatment of the comprehensive physicalist view that, in some important sense, everything is physical. Andrew Melnyk argues that the view is best formulated by appeal to a carefully worked-out notion of realization, rather than supervenience; that, so formulated, physicalism must be importantly reductionist; that it need not repudiate causal and explanatory claims framed in non-physical language; and that it has the a posteriori epistemic status of a broad-scope scientific hypothesis. Two concluding chapters argue in (...) detail that contemporary science provides no significant empirical evidence against physicalism and some considerable evidence for it. Written in a brisk, candid and exceptionally clear style, this 2003 book should appeal to professionals and students in philosophy of mind, metaphysics and philosophy of science. (shrink)

Written with a student audience in mind, this article surveys the issues raises by the attempt to formulate, argue for, and explore the implications of a comprehensively physicalist view of the world.

Realization can be roughly understood as a kind of role-playing, a relationship between a property that plays a role and a property characterized by that role. This rough sketch previously received only moderate elaboration; recently, however, several substantive theories of realization have been proposed. But are there any general constraints on a theory of realization? What is a theory of realization supposed to accomplish? I first argue that a view of realization is viable, in part, to the extent that physical (...) realization under that view explains or accounts for why instances of realized properties are necessitated by how things are physically in a modally strong sense. In this sense, I claim that physical realization should explain physical supervenience. I then call into question two alternative desiderata and raise a challenge for attempts to explicate realization in terms of isomorphism or analogy. Finally, I explain how a causal-functional account of realization, as well as less demanding accounts, can meet the preferred desideratum. (shrink)

In his recent article ‘Consciousness and Reduction’, Ausonio Marras argues that functional reduction must appeal to bridge laws and thus does not represent a genuine alternative to Nagelian reduction. In response, I first argue that even if functional reduction must use bridge laws, it still represents a genuine alternative to Nagelian reduction. Further, I argue that Marras does not succeed in showing that functional reduction must use bridge laws. Introduction Nagelian Reduction, Functional Reduction, and Bridge Laws Marras on Functional Reduction (...) The Logical Space of ‘Bridge Law’ Views of Reduction [RP] as an Account of Realization Conclusion CiteULike Connotea Del.icio.us What's this? (shrink)

In Natural Minds Thomas Polger advocates, and defends, the philosophical theory that mind equals brain -- that sensations are brain processes -- and in doing so brings the mind-brain identity theory back into the philosophical debate about consciousness. The version of identity theory that Polger advocates holds that conscious processes, events, states, or properties are type- identical to biological processes, events, states, or properties -- a "tough-minded" account that maintains that minds are necessarily indentical to brains, a position held by (...) few current identity theorists. Polger's approach to what William James called the "great blooming buzzing confusion" of consciousness begins with the idea that we need to know more about brains in order to understand consciousness fully, but recognizes that biology alone cannot provide the entire explanation. Natural Minds takes on issues from philosophy of mind, philosophy of science, and metaphysics, moving freely among them in its discussion.Polger begins by answering two major objections to identity theory -- Hilary Putnam's argument from multiple realizability and Saul Kripke's modal argument against mind-brain identity. He then offers a detailed account of functionalism and functional realization, which offer the most serious obstacle to consideration of identity theory. Polger argues that identity theory can itself satisfy the kind of explanatory demands that are often believed to favor functionalism. (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)

My topic is the confluence of two recently active philosophical research programs. One research program concerns the metaphysics of realization. The other research program concerns scientific explanation in terms of mechanisms. In this paper I introduce a distinction between descriptive and explanatory approaches to realization. I then use this distinction to argue that a well-known account of realization, due to Carl Gillett, is incompatible with a well-known account of mechanistic explanation, due to Peter Machamer, Lindley Darden, and Carl Craver (MDC, (...) Philos Sci 57: 1-25, 2000). This is surprising, not least of which because Gillett has cited MDC's work as evidence that his account of realization is the right way to think about realization in the sciences. (shrink)

According to the received view in philosophy of mind, mental states or properties are _realized_ by brain states or properties but are not identical to them. This view is often called _realization_ _physicalism_. Carl Gillett has recently defended a detailed formulation of the realization relation. However, Gillett’s formulation cannot be the relation that realization physicalists have in mind. I argue that Gillett’s “dimensioned” view of realization fails to apply to a textbook case of realization. I also argue Gillett counts as (...) realization some cases that should not count if realization physicalism is to be distinguished from its competitors in the usual ways. I conclude that the relation described by Gillett cannot be realization. (shrink)

The view that the relationship between minds and brains can be thought of on the model of software and hardware is pervasive. The most common versions of the view, known as functionalism in philosophy of mind, hold that minds are realized by brains.

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)

Professor Hilary Putnam has been one of the most influential and sharply original of recent American philosophers in a whole range of fields. His most important published work is collected here, together with several new and substantial studies, in two volumes. The first deals with the philosophy of mathematics and of science and the nature of philosophical and scientific enquiry; the second deals with the philosophy of language and mind. Volume one is now issued in a new edition, including an (...) essay on the philosophy of logic first published in 1971. (shrink)

I articulate and defend a new theory of what it is for a physical system to implement an abstract computational model. According to my descriptivist theory, a physical system implements a computational model just in case the model accurately describes the system. Specifically, the system must reliably transit between computational states in accord with mechanical instructions encoded by the model. I contrast my theory with an influential approach to computational implementation espoused by Chalmers, Putnam, and others. I deploy my theory (...) to illuminate the relation between computation and representation. I also rebut arguments, propounded by Putnam and Searle, that computational implementation is trivial. (shrink)

Under what conditions does a physical system implement or realize a computation? Structuralism about computational implementation, espoused by Chalmers and others, holds that a physical system realizes a computation just in case the system instantiates a pattern of causal organization isomorphic to the computation’s formal structure. I argue against structuralism through counter-examples drawn from computer science. On my opposing view, computational implementation sometimes requires instantiating semantic properties that outstrip any relevant pattern of causal organization. In developing my argument, I defend (...) anti-individualism about computational implementation: relations to the social environment sometimes help determine whether a physical system realizes a computation. 1 The Physical Realization Relation2 Semantics and Computational Implementation3 Conforming to Instructions4 Implementing a Computer Program4.1 The denotational semantics of Scheme4.2 Worries about intentionality4.3 Worries about the natural numbers5 Implementing a Machine Model6 Bounded Structuralism7 Triviality Arguments8 Anti-individualism about Computational Implementation. (shrink)

After briefly discussing the relevance of the notions computation and implementation for cognitive science, I summarize some of the problems that have been found in their most common interpretations. In particular, I argue that standard notions of computation together with a state-to-state correspondence view of implementation cannot overcome difficulties posed by Putnam's Realization Theorem and that, therefore, a different approach to implementation is required. The notion realization of a function, developed out of physical theories, is then introduced as a replacement (...) for the notional pair computation-implementation. After gradual refinement, taking practical constraints into account, this notion gives rise to the notion digital system which singles out physical systems that could be actually used, and possibly even built. (shrink)

This volume brings together a number of perspectives on the nature of realization explanation and experimentation in the ‘special’ and biological sciences as well as the related issues of psychoneural reduction and cognitive extension. The first two papers in the volume may be regarded as offering direct responses to the questions: (1) What model of realization is appropriate for understanding the metaphysics of science? and (2) What kind of philosophical work is such a model ultimately supposed to do?

Where does the mind begin and end? Most philosophers and cognitive scientists take the view that the mind is bounded by the skull or skin of the individual. Robert Wilson, in this provocative and challenging 2004 book, provides the foundations for the view that the mind extends beyond the boundary of the individual. The approach adopted offers a unique blend of traditional philosophical analysis, cognitive science, and the history of psychology and the human sciences. A forthcoming companion volume Genes and (...) the Agents of Life will explore the theme in the biological sciences. Written with verve and clarity, this ambitious book will appeal to a broad swathe of professionals and students in philosophy, psychology, cognitive science, and the history of the behavioural and human sciences. (shrink)

This paper examines the standard view of realization operative incontemporary philosophy of mind, and proposes an alternative, generalperspective on realization. The standard view can be expressed, insummary form, as the conjunction of two theses, the sufficiency thesis andthe constitutivity thesis. Physicalists of both reductionist and anti-reductionist persuasions share a conception of realization wherebyrealizations are determinative of the properties they realize and physically constitutive of the individuals with those properties. Centralto the alternative view that I explore here is the idea that (...) the requisite,metaphysically robust notion of realization is ineliminably context-sensitive. I shall argue that the sufficiency and constitutivity theses aretypically not jointly satisfied by any one candidate realizer, and that goingcontext-sensitive in one's metaphysics is preferable to the standard view.The context-sensitive views developed here are implicit in a range ofcommon views in both the philosophy of mind and the philosophy of biology,even if they have not been explicitly articulated, and even though theyundermine other views that are commonly endorsed. (shrink)

In Zhong (Philos Phenomenol Res 83:129–147, 2011; Analysis 72:75–85, 2012), I argued that, contrary to what many people might expect, the counterfactual theory of causation will generate (rather than solve) the exclusion problem. Recently some philosophers raise an incisive objection to this argument. They contend that my argument fails as it equivocates between different notions of a physical realizer (see Christensen and Kallestrup in Analysis 72:513–517, 2012). However, I find that their criticism doesn’t threaten the central idea of my view. (...) In this paper, I make two separate responses that appeal to two unequivocal notions of physical realizers, respectively. I aim to show that a modified argument that uses either notion would work. (shrink)