Tom Polger

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.

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.

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.

According to the multiple realization argument, mental states or processes can be realized in diverse and heterogeneous physical systems; and that fact implies that mental state or process kinds cannot be identified with particular kinds of physical states or processes. More specifically, mental processes cannot be identified with brain processes. Moreover, the argument provides a general model for the autonomy of the special sciences. The multiple realization argument is widely influential, but over the last thirty years it has also faced serious objections. Despite those objections, most philosophers regard the fact of multiple realization and the cogency of the multiple realization argument as plainly correct. Why is that? What is it about the multiple realization argument that makes it so resilient? One reason is that the multiple realization argument is deeply intertwined with a view that minds are, in some sense, computational. But we argue that the sense in which minds are computational does not support the conclusion that they are ipso facto multiply realized. We argue that the sense in which brains compute does not imply that brains implement multiply realizable computational processes, and it does not provide a general model for the autonomy of the special sciences.

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..

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

Mental and physical causes do not competedthe presence of one does not exclude the efficacy of the other. This point is obvious from the perspective of an interventionist theory of causation, but only when this theory gets its proper due. Doubts about the interventionist justification for concluding that there is both physical and mental causation, we have argued, rest on misunderstandings of interventionism. When looking to interventions to reveal causal structures, care must be taken to consider the right variable sets. Jaegwon Kim’s diagram is the wrong starting point for interventionist causal reasoning because it includes variables that are related by non-causal relations in addition to causal relations. When it comes to understanding exclusion, less is more.

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.

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

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.

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.

Most practitioners of the metaphysics of science agree that it should be a naturalized metaphysics. But, just as in other areas of philosophy, there is no consensus on what constitutes naturalism. Here I will focus on just one aspect, viz., the idea that the metaphysics of science should be epistemically naturalized. In the first section I will characterize the kind of epistemic naturalism relevant to the metaphysics of science. The main idea, drawing on the work of Penelope Maddy, is that metaphysical inquiry is to be conducted and metaphysical claims justified in the very same way that scientific inquiry is conducted and scientific claims are justified. I then examine two prominent examples of metaphysicians of science proposing to “naturalize” the metaphysics of science, and argue that they fail to be epistemically natural. These are approaches due to James Ladyman and Don Ross, and to Anjan Chakravartty. Considering their failures shows us a way forward for naturalized metaphysics of science that is both more metaphysical and more scientific.

This collection offers cutting-edge chapters on themes related to the philosophical work of Owen Flanagan. Flanagan is an influential philosopher in the late 20th and early 21st Century, whose wide-ranging work spans philosophy of mind (especially consciousness, identity, and the self), ethics and moral psychology, comparative philosophy, and philosophical study of psychopathology (especially disorders of self, dreams, and addiction). Flanagan is the author of numerous scholarly and popular articles, and of 10 books. The chapters present proposals for productive interdisciplinary research exploring the mind, ethics, personhood, consciousness, religious cognition, mental disorders, addiction, the narrative self, virtue, the social sciences, forgiveness, or comparative philosophy.

Reasoning about consciousness concerns theoretical connections between the etiology of consciousness and philosophical theories of its nature. Discussions concerning the origins of consciousness are different from those about the origins of hearts, lungs, and stomachs. And it is these lines of reasoning that concern this chapter. Before examining some arguments concerning the evolution of consciousness, we need to understand what a good explanation of the adaptation of consciousness would look like. The chapter outlines a few explanations of the etiology of consciousness that attempt to go beyond just‐so stories. It uses the terminology of evolutionary theory, the theory of the origins and natural histories of organisms and their traits. The chapter then evaluates the role that evolutionary explanations are claimed to play in broader theorizing about consciousness. It also considers some of the most prominent questions that arise in evolutionary reasoning about consciousness.

Godfrey-Smith begins with the particular, with the peculiarities of some creatures in a small corner of the animal kingdom, and builds up his reasoning and evidence through a series of detailed comparisons with other creatures. He often finds that similar effects have different causes, and appears to rely on the inverse of the Newtonian principle, namely, that similar causes will have similar effects. But the similarities and differences that occupy Godfrey-Smith are not only or mainly by comparison with humans or mammals. His story is as much about how octopuses and cuttlefish differ from other mollusks and from their common ancestors as about how they behave in ways commonly associated with vertebrates.