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)
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)
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)
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)
Forthcoming in Philosophy of Science. Despite some recent advances, multiple realization remains a largely misunderstood thesis. Consider the dispute between Lawrence Shapiro and Carl Gillett over the application of Shapiro’s recipe for deciding when we have genuine cases of multiple realization. I argue that Gillett follows many philosophers in mistakenly supposing that multiple realization is absolute and transitive. Both of these are problematic. They are tempting only when we extract the question of multiple realization from the explanatory context in which (...) it is invoked. Anchoring multiple realizability in its theoretical context provides grounds for arbitrating disagreements. Doing so, I argue, favors the view advanced by Shapiro. (shrink)
Fifty years ago J. J. C. Smart published his pioneering paper, “Sensations and Brain Processes.” It is appropriate to mark the golden anniversary of Smart’s publication by considering how well his article has stood up, and how well the identity theory itself has fared. In this paper I first revisit Smart’s text, reflecting on how it has weathered the years. Then I consider the status of the identity theory in current philosophical thinking, taking into account the objections and replies that (...) Smart discussed as well as some that he did not anticipate. Finally, I offer a brief manifesto for the identity theory, providing a small list of the claims that I believe contemporary identity theorist should accept. As it turns out, these are more or less the ones that Smart defended fifty years ago. (shrink)
Todd Moody’s Zombie Earth thought experiment is an attempt to show that ‘conscious inessentialism’ is false or in need of qualification. We defend conscious inessentialism against his criticisms, and argue that zombie thought experiments highlight the need to explain why consciousness evolved and what function(s) it serves. This is the hardest problem in consciousness studies.
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)
Multiple realizability has recently attractedrenewed attention, for example Bickle, 1998;Bechtel and Mundale, 1999; Bechtel and McCauley,1999; Heil, 1999; and Sober, 1999. Many of thesewriters revisit the topic of multiplerealizability in order to show that someversion of a mind-brain identity theory isviable. Although there is much of value inthese recent explorations, they do not addressthe underlying intuitions that have vexedphilosophers of mind since Hilary Putnamintroduced the concern (1967). I argue that thestandard way of construing multiplerealizability is a much stronger claim thanthat (...) of Putnam's intuition alone. I distinguishfour interpretations of the multiplerealizability intuition. Some commonformulations of multiple realizability arealmost certainly true, while others are not atall plausible. I argue that the plausible formsof multiple realizability do not impugn theprospects for a mind-brain Identity Theory. (shrink)
Issues of identity and reduction have monopolized much of the philosopher of mind’s time over the past several decades. Interestingly, while investigations of these topics have proceeded at a steady rate, the motivations for doing so have shifted. When the early identity theorists, e.g. U. T. Place ( 1956 ), Herbert Feigl ( 1958 ), and J. J. C. Smart ( 1959 , 1961 ), fi rst gave voice to the idea that mental events might be identical to brain processes, (...) they had as their intended foil the view that minds are immaterial substances. But very few philosophers of mind today take this proposal seriously. Why, then, the continued interest in identity and reduction? Th e concern, as philosophers like Hilary Putnam and Jerry Fodor have expressed it, is that a victory for identity or reduction is a defeat for psychology. For if minds are physical, or if mental events are physical events, then psychologists might as well disassemble their laboratories, making room for the neuroscientists and molecular biologists who are in a better position to explain those phenomena once misdescribed as “psychological.” Th e worry nowadays is not that locating thought in immaterial souls will make psychology intractable, but that locating thoughts in material brains will make it otiose. (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.
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)
Karen Bennett has recently articulated and defended a “compatibilist” solution to the causal exclusion problem. Bennett’s solution works by rejecting the exclusion principle on the grounds that even though physical realizers are distinct from the mental states or properties that they realize, they necessarily co-occur such that they fail to satisfy standard accounts of causal over-determination. This is the case, Bennett argues, because the causal background conditions for core realizers being sufficient causes of their effects are identical to the “surround” (...) conditions with which the core realizers are metaphysically sufficient the states or properties that they realize. Here we demonstrate that the background conditions for the causal sufficiency of core realizers for their effects are not identical to the core realizer’s surrounds, nor do backgrounds necessitate such surround conditions. If compatibilist solutions to exclusion can be defended, a different argument will be needed. (shrink)
Consciousness and evolution are complex phenomena. It is sometimes thought that if adaptation explanations for some varieties of consciousness, say, conscious visual perception, can be had, then we may be reassured that at least those kinds of consciousness are not epiphenomena. But what if other varieties of consciousness, for example, dreams, are not adaptations? We sort out the connections among evolution, adaptation, and epiphenomenalism in order to show that the consequences for the nature and causal efficacy of consciousness are not (...) as dire as has sometimes been supposed. (shrink)
G. E. Moore argues that goodness is an intrinsic non-natural property that supervenes irreducibly on the intrinsic natural properties of its bearers. Accordingly, it is often supposed that “Moorean” supervenience is incompatible with physicalism, a naturalistic thesis. In this paper I argue that Moorean supervenience is not in itself incompatible with physicalism, Moore’s ethical non-naturalism notwithstanding. Understanding why will help us to better appreciate the full range of resources available to physicalists.
Some people believe that there is an “explanatory gap” between the facts of physics and certain other facts about the world—for example, facts about consciousness. The gap is presented as a challenge to any thoroughgoing naturalism or physicalism. We believe that advocates of the explanatory gap have some reasonable expectations that cannot be merely dismissed. We also believe that naturalistic thinkers have the resources to close the explanatory gap, but that they have not adequately explained how and why these resources (...) work. In this paper we isolate the legitimate explanatory demands in the gap reasoning, as it is defended by Chalmers and Jackson . We then argue that these demands can be met. Our solution involves a novel proposal for understanding the relationship between theories, explanations, and scientific identities. (shrink)
Do facts about water have a priori, transparent, reductive explanations in terms of microphysics? Ned Block and Robert Stalnaker hold that they do not. David Chalmers and Frank Jackson hold that they do. In this paper I argue that Chalmers.
Rosenberg does not provide arguments for some crucial premises in his argument against physicalism. In particular, he gives no independent argument to show that physicalists must accept the entry-by-entailment thesis. The arguments provided establish weaker premises than those that are needed. As a consequence, Rosenberg.
In this article I reply to the challenge set forth by Dennett in his critique of Flanagan and Polger (1995). Through careful textual analysis, I show that Dennett is presenting us with a dilemma and that this dilemma is the keystone of Dennett’s argument in his Consciousness Explained. I argue that one horn of the dilemma does not have the consequence that Dennett claims; Specifically, I argue that theories that allow for the possibility of non-conscious functional duplicates of conscious beings (...) (so called zombies) do not thereby entail epiphenomenalism about consciousness. I demonstrate how Dennett’s argument falls prey to a common mistake in reasoning about the functions of things, and recommend a correction. (shrink)
Identity theories are those that hold that 'sensations are brain processes'. In particular, they hold that mental/psychological state kinds are identical to brain/neuroscientific state kinds. In this paper, I isolate and explain some of the key features of contemporary identity theories. They are then contrasted with the main live alternatives by means of considering the two most important lines of objection to identity theories.
A widely accepted theory holds that emotional experiences occur mainly in a part of the human brain called the amygdala. A different theory asserts that color sensation is located in a small subpart of the visual cortex called V4. If these theories are correct, or even approximately correct, then they are remarkable advances toward a scientific explanation of human conscious experience. Yet even understanding the claims of such theories—much less evaluating them—raises some puzzles. Conscious experience does not present itself as (...) a brain process. Indeed experience seems entirely unlike neural activity. For example, to some people it seems that an exact physical duplicate of you could have different sensations than you do, or could have no sensations at all. If so, then how is it even possible that sensations could turn out to be brain processes? (shrink)
Recently some philosophers interested in consciousness have begun to turn their attention to the question of what evolutionary advantages, if any, being conscious might confer on an organism. The issue has been pressed in recent dicussions involving David Chalmers, Todd Moody, Owen Flanagan and Thomas Polger, Daniel Dennett, and others. The purpose of this essay is to consider some of the problems that face anyone who wants to give an evolutionary explanation of consciousness. We begin by framing the problem in (...) the context of some current debates. Then we. (shrink)
Saul Kripke’s modal essentialist argument against materialism remains an obstacle to any prospective Identity Theorist. This paper is an attempt to make room for an Identity Theory without dismissing Kripke’s analytic tools or essentialist intuitions. I propose an explanatory model that can make room for the Identity Theory within the constraints of Kripke’s view; the model is based on ideas from Alan Sidelle’s, “Identity and Identity-like” . My model explains the apparent contingency of some scientific identities by appealing to our (...) epistemic access to the conditions of identity for sensations and brain processes. Pace Kripke, the Identity Theorist can thus explain away the apparent contingency of mind-brain identity claims. (shrink)
David Chalmers burst onto the philosophical scene in the mid-1990s with his work on consciousness, which awakened slumbering zombie arguments against physicalism and transformed the explanatory gap into the hard problem of consciousness. The distinction between hard and easy problems of consciousness became a central dogma of the movement. Chalmers’ influence in philosophy and consciousness studies is unquestionable. But enthusiasts of Chalmers’ work on consciousness may be excused for not fully appreciating his own justification for drawing the hard/easy distinction, or (...) even exactly which distinction he is drawing. Consequently, it is not clear that the ‘Chalmers’ hard problem’ that has been widely influential is Chalmers’ ‘hard problem’ of consciousness. Chalmers’ ‘hard problem’ rests on, among other things: a methodological view about how philosophy—metaphysics, especially—ought to be conducted; a view about the requirements for explanation and reduction in philosophy and in the sciences; and a theory of the semantics of concepts.1 Although Chalmers writes that the present book is not intended as a foundation for his. (shrink)
What Are Zombies? Zombies are stipulated to be creatures that are in some way identical to human beings-and thus, in some sense, indistinguishable from human beings-but which lack consciousness. Zombies are at least behaviorally identical to human beings or other conscious creatures, and they may also be like us in other ways.
To what degree must the brains and bodies of creatures with minds have to be similar to the brains and bodies of human beings? Since the late 1960’s, most philosophers and cognitive scientists have supposed that there a relatively few constraints on what sorts of brains and bodies can realize minds. It is widely believed that minds are multiply realizable. Of course there were always dissenters, and in recent years their grumbling has grown harder to dismiss. In The Mind Incarnate (...) , Lawrence Shapiro provides the first book-length study of the multiple realizability thesis. Such an examination is long overdue, and Shapiro’s treatment is sure to set the standard for the budding debate. (shrink)
Saying that psychological states are functional states, the functionalist claims more than that psychological states have functions. Rather, functionalism is the theory that psychological states are defined and constituted by their functions. On this view, what it is to be a psychological state of a certain sort just is and consists entirely of having a certain function. Anything that has that function in a suitable system would therefore be that psychological state. If storing information for later use is the essential (...) function of memory, then anything that has that function counts as a memory. Similarly, one might say that anything that traps or kills mice counts as a mouse trap. (shrink)
By now it is cliché to observe that so-called reductionism is not one mammoth doctrine. There are, as it were, many reductionisms. Needless to say, there are at least as many antireductionisms. Despite the fact that neither reductionisms nor their counterparts are single and unified doctrines there do seem to be some family resemblances. One, it seems to me, is that both reductionisms and antireductionisms are acute responses to certain metaphysical worries. Some of these worries are metaphysical in nature, and (...) others are worries about the nature of metaphysics. My contention is that these worries are by and large misguided, and thus that the anxious reactions of both reductionists and antireductionists are unwarranted. For the present purposes I will distinguish between reductionist and antireductionist theses, on the one hand, and reductionist and antireductionist approaches, on the other. This is a perhaps clumsy distinction, and I don’t know that it carves reductionism at its joints. But I think it can be made to do some work. By theses I have in mind particular views about the nature of reduction and reductive relations, which can be worked out in various ways some of which will be discussed below. By approaches I have in mind the motivations and background assumptions that go into formulating or adopting particular theses. Individual reductionists and antireductionists usually hold what we might then call a theory, a combination of an approach and a thesis. A great deal has been written about the merits of or truth of any number of 1 reductionist or antireductionist theses. Presumably there are some assumptions about approaches and motivations lurking in the background. But very little has been said about the merits of the various approaches themselves. Put another way: There is a lively debate over whether particular reductionist theses can solve certain problems or avoid certain objections. But not enough attention has been given to whether these are problems worth solving or objections worth overcoming. (shrink)
Michael Tye has recently been a vocal defender of color realism or, as I shall call it, color objectivism. Objectivism about color is the view that color properties are identical to intrinsic physical properties of the surfaces of objects. Subjectivism about color is the denial of color objectivism. Objectivists argue that color claims must be taken at face value. In this paper I forego the usual bickering about whether there are surface reflectance properties that can be identified with colors as (...) the objectivist theory requires. Supposing that some such properties could be found, I argue that if objectivism about color were correct it would have the unsavory consequence that we are rarely if ever right—perhaps never right—about the particular colors of particular things. So objectivism does not bear out common attribution of colors to the surfaces of things, after all. (shrink)
The enduring metaphysical question about minds and mental phenomena concerns their nature. At least since Descartes this question—the mind-body problem—has been understood in terms of the viability or necessity of mind-body dualism, the thesis that minds and bodies are essentially distinct kinds of substance. Assuming that the nonmental (‘body’) portions of the world are constituted of physical stuff, the remaining question is: Are minds or mental phenomena essentially distinct non-physical substances, or phenomena that essentially involve such distinct kinds of substances? (...) By the middle of the Twentieth Century there was broad philosophical and scientific consensus that the answer to this classical question about minds is negative: Minds and mental phenomena are not essentially distinct substances, nor are they phenomena that essentially involve distinct kinds of substances. There are at least two broad trends and one specific argument that lead to this conclusion. One trend is the decreasing influence of specifically theological arguments and commitments in philosophical argumentation, so that religious belief in immortal souls was no longer given much weight in the ontology of mind. The second trend, perhaps related to the first, is the increased demand that metaphysical theories bear explanatory fruits, so that the postulation of an immaterial and essentially mental substance appears to be a abdication from explanatory duties rather than a useful proposal. The argument, known to Descartes from the very beginning, is that there has never been an adequate account of 1 how two essentially distinct and incompatible substances could causally interact.1 Descartes’ solution was inadequate and brute, and his followers struggled with the problem—leading to Leibniz’s parallelism and Malebranche’s occasionalism, among other views. The problem of mental causation, then, is the central difficulty that underines substance dualism.2 The negative answer on the question of substance dualism, however, only increases the pressure for some monistic account of the nature of minds.. (shrink)
It is commonly held that there are two obstacles to precisely formulating the doctrine of physicalism: Hempel’s Problem, and Hume’s Problem.2 Hempel’s Problem is that if physicalism is to be formulated in terms of physics—or in terms of any science, for the problem is fully general if it is a problem at all—whether to use the current or future science. If physicalism is formulated in terms of current physics, then it is most likely false because current physics is at least (...) very likely to be false and is perhaps known to be incomplete or inconsistent. If physicalism is formulated in terms of future physics, then (the worry goes) physicalism will prove to be trivial, vacuous, or simply of indeterminate content. Horgan offers no direct guidance on Hempel’s Problem, though he seems to adopt a future-physics view.3. (shrink)
The 1990’s, we’ve been told, were the decade of the brain. But without anyone announcing or declaring, much less deciding that it should be so, the 90’s were also a breakthrough decade for the study of consciousness. (Of course we think the two are related, but that is another matter altogether.) William G. Lycan leads the charge with his 1987 book Consciousness (MIT Press), and he has weighed-in again with Consciousness and Experience (1996, MIT Press). Together these two books put (...) forth Lycan’s formidable view of consciousness, extending the theory of mind that he calls ‘homuncular functionalism.’ Roughly, Lycan’s view is that conscious beings are hierarchically composed intentional systems, whose representational powers are to be understood in terms of their biological function. In this review we will call the view ‘teleological functionalism’ or ‘teleofunctionalism’ – the homuncular part, for which Lycan and Daniel Dennett argued convincingly, is now so widely accepted that it fails to distinguish Lycan’s view from other versions of functionalism. This, by itself, is a testament to the importance of Lycan’s work. (shrink)
There is an argument for functionalism—and _ipso facto_ against identity theory—that can be sketched as follows: We are, or want to be, or should be dedicated to functional explanations in the sciences, or at least the special sciences. Therefore—according to the principle that what exists is what our ideal theories say exists—we are, or want to be, or should be committed to metaphysical functionalism. Let us call this the _argument from functional_ _explanation_. I will try to reveal the motivation for (...) making such an argument, and sketch the kind of response that should be made by critics of functionalism. (shrink)
I describe a feature of the debate between Functionalists and Anti-Functionalists in philosophy of mind that I call The Epiphenomenal Trap. I argue that the dialectic is a trap because neither side can resolve the central metaphysical issue as it has been put. That is because the debate typically trades in possible explanations. So long as Functionalists and Anti-Functionalists continue to debate whether functionalist explanations are possible, the central metaphysical issue cannot be resolved.
Drew Khlentozos’ Naturalistic Realism and the Antirealist Challenge is a meticulous introduction and roadmap to the core arguments of the contemporary realism/antirealism debate. It has several features that I especially admire. The book is carefully argued and for the most part clearly written. Rare among recent writers in Anglo-American philosophy, Khlentzos is a charitable reader of his opponents and earnestly endeavors to present their views as clearly and generously as possible. This generosity and thoroughness are also the book’s main fault, (...) as it is long (weighing in 408 pages) and sometimes plodding. In a few cases Khlentzos’ charity is overly generous. This seems to me to be the case, for example, with some of his contortions on behalf of Dummett, not least of which being a lengthy chapter on how intuitionism drives Dummett’s antirealism that probably should have been an appendix. But these are drawbacks that we can all live with—especially for the purpose of graduate teaching, for which this monograph is well suited. Naturalistic Realism and the Antirealist Challenge begins (Section I) by setting out the realist/anti-realist debate. Khlentzos argues that the kinds of metaphysical realists who have been quickest to shrug off semantic arguments against realism are particularly susceptible to those arguments. Specifically, naturalistic realists—among whom Khlentzos counts himself—cannot dismiss critiques like those from Dummett and Putnam merely by observing that realism is a metaphysical rather than semantic or epistemic doctrine. The trouble is, “If the world is as resolutely mind-independent as the realist makes out, then there is a problem about how we get to know about it in the first place” (4). Khlentzos calls this the representation problem, saying. (shrink)
In the early years of the 1990s, a number of philosophers and cognitive scientists became enthused about the idea that mental states are spatially and temporally distributed in the brain, and that this has significant consequences for philosophy of mind. Daniel Dennett (1991), for example, appealed to the spatial and temporal distribution of cognitive processes in the brain in order to argue that there is no unified place where or time when consciousness occurs in the brain. Dennett used this interim (...) conclusion as a premise in a series of arguments designed to undermine what he calls the “Cartesian Theater” view of consciousness, according to which there is an independent and fact of the matter about when and where conscious mental states occur. Most famously, Dennett argues that anyone who believes there are such facts of the matter must choose between “Orwellian” and “Stalinesque” theories of the timing of consciousness, in order to accommodate certain data about the spatial distribution of the timing of consciousness-related brain events. But, he claims, that distinction is a distinction without a difference: The choice between “Orwellian” and “Stalinesque” views is either nonsense, or at the very least one that we could never be justified in making. And this, Dennett takes it, is a reductio ad absurdum of any theory of consciousness that says there is a fact of the matter about when and where is occurs. (shrink)