The biological functions debate is a perennial topic in the philosophy of science. In the first full-length account of the nature and importance of biological functions for many years, Justin Garson presents an innovative new theory, the 'generalized selected effects theory of function', which seamlessly integrates evolutionary and developmental perspectives on biological functions. He develops the implications of the theory for contemporary debates in the philosophy of mind, the philosophy of medicine and psychiatry, the philosophy of biology, and biology itself, (...) addressing issues ranging from the nature of mental representation to our understanding of the function of the human genome. Clear, jargon-free, and engagingly written, with accessible examples and explanatory diagrams to illustrate the discussion, his book will be highly valuable for readers across philosophical and scientific disciplines. (shrink)

This book is a critical survey of and guidebook to the literature on biological functions. It ties in with current debates and developments, and at the same time, it looks back on the state of discourse in naturalized teleology prior to the 1970s. It also presents three significant new proposals. First, it describes the generalized selected effects theory, which is one version of the selected effects theory, maintaining that the function of a trait consists in the activity that led to (...) its differential persistence or reproduction in a population, and not merely its differential reproduction. Secondly, it advances “within-discipline pluralism” (as opposed to between-discipline pluralism) a new form of function pluralism, which emphasizes the coexistence of function concepts within diverse biological sub-disciplines. Lastly, it provides a critical assessment of recent alternatives to the selected effects theory of function, namely, the weak etiological theory and the systems-theoretic theory. The book argues that, to the extent that functions purport to offer causal explanations for the existence of a trait, there are no viable alternatives to the selected effects view. -/- The debate about biological functions is still as relevant and important to biology and philosophy as it ever was. Recent controversies surrounding the ENCODE Project Consortium in genetics, the nature of psychiatric classification, and the value of ecological restoration, all point to the continuing relevance to biology of philosophical discussion about the nature of functions. In philosophy, ongoing debates about the nature of biological information, intentionality, health and disease, mechanism, and even biological trait classification, are closely related to debates about biological functions. (shrink)

Since the time of Hippocrates, madness has typically been viewed through the lens of disease, dysfunction, and defect. In 'Madness', philosopher of science Justin Garson presents a radically different paradigm for conceiving of madness and the forms that it takes. In this paradigm, which he calls madness-as-strategy, madness is neither a disease nor a defect, but a designed feature, like the heart or lungs.

I present and defend the generalized selected effects theory (GSE) of function. According to GSE, the function of a trait consists in the activity that contributed to its bearer’s differential reproduction, or differential retention, within a population. Unlike the traditional selected effects (SE) theory, it does not require that the functional trait helped its bearer reproduce; differential retention is enough. Although the core theory has been presented previously, I go significantly beyond those presentations by providing a new argument for GSE (...) and defending it from a recent objection. I also sketch its implications for teleosemantics and philosophy of medicine. (shrink)

Mainstream teleosemantics is the view that mental representation should be understood in terms of biological functions, which, in turn, should be understood in terms of selection processes. One of the traditional criticisms of teleosemantics is the problem of novel contents: how can teleosemantics explain our ability to represent properties that are evolutionarily novel? In response, some have argued that by generalizing the notion of a selection process to include phenomena such as operant conditioning, and the neural selection that underlies it, (...) we can resolve this problem. Here, we do four things: we develop this suggestion in a rigorous way through a simple example, we draw on recent neurobiological research to support its empirical plausibility, we defend the move from a host of objections in the literature, and we sketch how the picture can be extended to help us think about more complex “conceptual” representations and not just perceptual ones. (shrink)

This article presents a distinct sense of ‘mechanism’, which I call the functional sense of mechanism. According to this sense, mechanisms serve functions, and this fact places substantive restrictions on the kinds of system activities ‘for which’ there can be a mechanism. On this view, there are no mechanisms for pathology; pathologies result from disrupting mechanisms for functions. Second, on this sense, natural selection is probably not a mechanism for evolution because it does not serve a function. After distinguishing this (...) sense fromsimilar explications of ‘mechanism’, I argue that it is ubiquitous in biology and has valuable epistemic benefits. (shrink)

I distinguish two forms of pluralism about biological functions, between-discipline pluralism and within-discipline pluralism. Between-discipline pluralism holds that different theories of function are appropriate for different subdisciplines of biology and psychology. I provide reasons for rejecting this view. Instead, I recommend within-discipline pluralism, which emphasizes the plurality of function concepts at play within any given subdiscipline of biology and psychology.

Theories of function are conventionally divided up into historical and ahistorical ones. Proponents of ahistorical theories often cite the ahistoricity of their accounts as a major virtue. Here, I argue that none of the mainstream “ahistorical” accounts are actually ahistorical. All of them embed, implicitly or explicitly, an appeal to history. In Boorse’s goal-contribution account, history is latent in the idea of statistical-typicality. In the propensity theory, history is implicit in the idea of a species’ natural habitat. In the causal (...) role theory, history is required for making sense of dysfunction. I elaborate some consequences for the functions debate. (shrink)

We sketch a novel and improved version of Boorse’s biostatistical theory of functions. Roughly, our theory maintains that (i) functions are non-negligible contributions to survival or inclusive fitness (when a trait contributes to survival or inclusive fitness); (ii) situations appropriate for the performance of a function are typical situations in which a trait contributes to survival or inclusive fitness; (iii) appropriate rates of functioning are rates that make adequate contributions to survival or inclusive fitness (in situations appropriate for the performance (...) of that function); and (iv) dysfunction is the inability to perform a function at an appropriate rate in appropriate situations. Based on our theory, we sketch solutions to three problems that have afflicted Boorse’s theory of function, namely, Kingma’s ([2010]) problem of the situation-specificity of functions, the problem of multi-functional traits, and the problem of how to distinguish between appropriate and inappropriate rates of functioning. (shrink)

There is a certain metaphor that has enjoyed tremendous longevity in the evolution of ageing literature. According to this metaphor, nature has a certain goal or purpose, the perpetuation of the species, or, alternatively, the reproductive success of the individual. In relation to this goal, the individual organism has a function, job, or task, namely, to breed and, in some species, to raise its brood to maturity. On this picture, those who cannot, or can no longer, reproduce are somehow invisible (...) to, or even dispensable to, the evolutionary process. Here, I argue that the metaphor should be discarded, not on the grounds that it is a metaphor, but on the grounds that this particular metaphor distorts our understanding of the evolution of ageing. One reason the metaphor is problematic is that it frames senescence and death as nature’s verdict on the value of older individuals. Instead, we should explore a different metaphor: the lengthy post-reproductive period in humans and some other animals is not an accident of culture, but designed by nature for the purpose of supporting and guiding younger generations. On this alternate picture, different stages of life have their own evolutionary rationales, their distinctive design features, their special mandates. (shrink)

This paper argues that proper functions are proximal functions. In other words, it rejects the notion that there are distal biological functions – strictly speaking, distal functions are not functions at all, but simply beneficial effects normally associated with a trait performing its function. Once we rule out distal functions, two further positions become available: dysfunctions are simply failures of proper function, and pathological conditions are dysfunctions. Although elegant and seemingly intuitive, this simple view has had surprisingly little uptake in (...) the literature. Indeed, our position departs from that of almost every theorist who has engaged with the issue at any depth. We start by presenting three arguments for the position that proper functions are proximal: one from the specificity of functions, one from their relation to intervention, and one from their relation to pathology. We then consider two case studies evidencing the trouble that accepting distal functions causes for philosophical reflection on the nature of pathological conditions. Finally, we anticipate and respond to three objections: that there can be failure of function without dysfunction; that our account is unacceptably revisionary in respect of normal function-talk; and that our thesis over-generalises from a narrow set of cases. (shrink)

Designed for use by philosophy students, this 2006 book provides an accessible, yet technically sound treatment of modal logic and its philosophical applications. Every effort has been made to simplify the presentation by using diagrams in place of more complex mathematical apparatus. These and other innovations provide philosophers with easy access to a rich variety of topics in modal logic, including a full coverage of quantified modal logic, non-rigid designators, definite descriptions, and the de-re de-dictio distinction. Discussion of philosophical issues (...) concerning the development of modal logic is woven into the text. The book uses natural deduction systems and also includes a diagram technique that extends the method of truth trees to modal logic. This feature provides a foundation for a novel method for showing completeness, one that is easy to extend to systems that include quantifiers. (shrink)

A common misunderstanding of the selected effects theory of function is that natural selection operating over an evolutionary time scale is the only functionbestowing process in the natural world. This construal of the selected effects theory conflicts with the existence and ubiquity of neurobiological functions that are evolutionary novel, such as structures underlying reading ability. This conflict has suggested to some that, while the selected effects theory may be relevant to some areas of evolutionary biology, its relevance to neuroscience is (...) marginal. This line of reasoning, however, neglects the fact that synapses, entire neurons, and potentially groups of neurons can undergo a type of selection analogous to natural selection operating over an evolutionary time scale. In the following, I argue that neural selection should be construed, by the selected effect theorist, as a distinct type of function-bestowing process in addition to natural selection. After explicating a generalized selected effects theory of function and distinguishing it from similar attempts to extend the selected effects theory, I do four things. First, I show how it allows one to identify neural selection as a distinct function-bestowing process, in contrast to other forms of neural structure formation such as neural construction. Second, I defend the view from one major criticism, and in so doing I clarify the content of the view. Third, I examine drug addiction to show the potential relevance of neural selection to neuroscientific and psychological research. Finally, I endorse a modest pluralism of function concepts within biology. (shrink)

For some, biology explains all there is to know about the mind. Yet many big questions remain: is the mind shaped by genes or the environment? If mental traits are the result of adaptations built up over thousands of years, as evolutionary psychologists claim, how can such claims be tested? If the mind is a machine, as biologists argue, how does it allow for something as complex as human consciousness? The Biological Mind: A Philosophical Introduction explores these questions and more, (...) using the philosophy of biology to introduce and assess the nature of the mind. Drawing on the four key themes of evolutionary biology; molecular biology and genetics; neuroscience; and biomedicine and psychiatry Justin Garson addresses the following key topics: moral psychology, altruism and levels of selection evolutionary psychology and modularity genes, environment and the nature-nurture debate neuroscience, reductionism and the relation between biology and free will function, selection and mental representation psychiatric classification and the maladapted mind. Extensive use of examples and case studies is made throughout the book, and additional features such as chapter summaries, annotated further reading and a glossary make this an indispensable introduction to those teaching philosophy of mind and philosophy of psychology. It will also be an excellent resource for those in related fields such as biology. (shrink)

What do the rules of logic say about the meanings of the symbols they govern? In this book, James W. Garson examines the inferential behaviour of logical connectives, whose behaviour is defined by strict rules, and proves definitive results concerning exactly what those rules express about connective truth conditions. He explores the ways in which, depending on circumstances, a system of rules may provide no interpretation of a connective at all, or the interpretation we ordinarily expect for it, or an (...) unfamiliar or novel interpretation. He also shows how the novel interpretations thus generated may be used to help analyse philosophical problems such as vagueness and the open future. His book will be valuable for graduates and specialists in logic, philosophy of logic, and philosophy of language. (shrink)

This is a short overview of the biological functions debate in philosophy. While it was fairly comprehensive when it was written, my short book ​A Critical Overview of Biological Functions has largely supplanted it as a definitive and up-to-date overview of the debate, both because the book takes into account new developments since then, and because the length of the book allowed me to go into substantially more detail about existing views.

Philosophers who study the problem of biological function often begin their deliberations by reflecting on the functions of parts of animals, or the behavior of animals. Applying theories of biological function to unconventional or borderline cases can help us to better evaluate and refine those theories. This is the case when we consider whether parts of transposable elements —bits of “selfish” DNA that move about within a host genome—have functions of their own, that is, whether the parts of TEs have (...) the function of helping the TE move about within the genome. Here I argue that whether or not the parts of TEs have functions depends crucially on whether collections of TEs form “populations,” by which I mean, here, a group of individuals of the same type that impact one another’s chances of persistence or multiplication, by impacting one another’s access to a shared resource. I think there is suggestive, but not conclusive, evidence that some TEs have functions of their own. Considering the problem of TE functionality, then, has value both for philosophy and for biology. (shrink)

What is it for an animal to be female, or male? An emerging consensus among philosophers of biology is that sex is grounded in some manner or another on anisogamy, that is, the ability to produce either large gametes (egg) or small gametes (sperm), though the exact nature of this grounding remains contentious. Here we argue for a new conception of this relation. In our view, one’s sex doesn’t depend on the kind of gamete one is capable of making, but (...) on the kind of gamete one is designed to make, where design is understood in terms of an evolutionary or ontogenetic selection process. Specifically, we argue that what it is to be, say, male, is to have a part or process that has the (proximal or distal) biological function of producing sperm. We outline and defend our view, and sketch some implications for scientific and social problems related to sex. (shrink)

Despite the voluminous literature on biological functions produced over the last 40 years, few philosophers have studied the concept of function as it is used in neuroscience. Recently, Craver (forthcoming; also see Craver 2001) defended the causal role theory against the selected effects theory as the most appropriate theory of function for neuroscience. The following argues that though neuroscientists do study causal role functions, the scope of that theory is not as universal as claimed. Despite the strong prima facie superiority (...) of the causal role theory, the selected effects theory (when properly developed) can handle many cases from neuroscience with equal facility. It argues this by presenting a new theory of function that generalizes the notion of a ‘selection process’ to include processes such as neural selection, antibody selection, and some forms of learning—that is, to include structures that have been differentially retained as well as those that have been differentially reproduced. This view, called the generalized selected effects theory of function, will be defended from criticism and distinguished from similar views in the literature. (shrink)

Over the last 20 years, several philosophers have developed a new approach to biological functions, the organizational approach. This is not a single theory but a family of theories based on the idea that a trait token can acquire a function by virtue of the way it contributes to a complex, organized system and thereby to its own continued persistence as a token. I argue that the organizational approach faces a serious liberality objection. I examine three different ways organizational theorists (...) have tried to avoid that objection and show how they fail. (shrink)

Christie, Brusse, et al. argue that the selected effects theory of function (SE) doesn’t do what it’s supposed to do: namely, show how functions can be explanatory. They survey some well-known evolutionary dynamics such as arms races, frequency-dependent fitness, and environmental heterogeneity, some of which have been discussed in the functions literature for decades. They argue that SE only seems to work because SE theorists ignore these dynamics. Their argument fails because they misrepresent what functions are supposed to explain and (...) how they’re supposed to do so. One reason for this failure is that they overlook the role of functions in the broader conversation about teleology in biology, one that has been unfolding for over 2000 years. (shrink)

Mechanisms, in the prominent biological sense of the term, are historical entities. That is, whether or not something is a mechanism for something depends on its history. Put differently, while your spontaneously-generated molecule-for-molecule double has a heart, and its heart pumps blood around its body, its heart does not have a mechanism for pumping, since it does not have the right history. My argument for this claim is that mechanisms have proper functions; proper functions are historical entities; so, mechanisms are (...) historical entities, too. This thesis runs against the mainstream new mechanist way of thinking about mechanisms, where mechanisms are generally thought of in an ahistorical way. After arguing for this thesis, I draw out some consequences for philosophy of science and metaphysics. (shrink)

The first use of the term "information" to describe the content of nervous impulse occurs 20 years prior to Shannon`s (1948) work, in Edgar Adrian`s The Basis of Sensation (1928). Although, at least throughout the 1920s and early 30s, the term "information" does not appear in Adrian`s scientific writings to describe the content of nervous impulse, the notion that the structure of nervous impulse constitutes a type of message subject to certain constraints plays an important role in all of his (...) writings throughout the period. The appearance of the concept of information in Adrian`s work raises at least two important questions: (i) what were the relevant factors that motivated Adrian`s use of the concept of information? (ii) What concept of information does Adrian appeal to, and how can it be situated in relation to contemporary philosophical accounts of the notion of information in biology? The first question involves an account of the application of communications technology in neurobiology as well as the historical and scientific background of Adrian`s major scientific achievement, which was the recording of the action potential of a single sensory neuron. The response to the second question involves an explication of Adrian`s concept of information and an evaluation of how it may be situated in relation to more contemporary philosophical explications of a semantic concept of information. I suggest that Adrian`s concept of information places limitations on the sorts of systems that are referred to as information carriers by causal and functional accounts of information. (shrink)

As historian Henning Schmidgen notes, the scientific study of the nervous system would have been “unthinkable” without the industrialization of communication in the 1830s. Historians have investigated extensively the way nerve physiologists have borrowed concepts and tools from the field of communications, particularly regarding the nineteenth-century work of figures like Helmholtz and in the American Cold War Era. The following focuses specifically on the interwar research of the Cambridge physiologist Edgar Douglas Adrian, and on the technology that led to his (...) Nobel-Prize-winning research, the thermionic vacuum tube. Many countries used the vacuum tube during the war for the purpose of amplifying and intercepting coded messages. These events provided a context for Adrian's evolving understanding of the nerve fiber in the 1920s. In particular, they provide the background for Adrian's transition around 1926 to describing the nerve impulse in terms of “information,” “messages,” “signals,” or even “codes,” and for translating the basic principles of the nerve, such as the all-or-none principle and adaptation, into such an “informational” context. The following also places Adrian's research in the broader context of the changing relationship between science and technology, and between physics and physiology, in the first few decades of the twentieth century. (shrink)

In this journal, Schulte develops a novel solution to the problem of distal content: by virtue of what is a mental representation about a distal object rather than a more proximal cause of that representation? Schulte maintains that in order for a representation to have a distal content, it must be produced by a constancy mechanism, along with two other conditions. I raise three objections to his solution. First, a core component of Schulte's solution is just a restrictive version of (...) Dretske's solution, but Schulte gives no argument for his restriction. Second, his proposed solution to a disjunction problem is ad hoc. Finally, his ‘far-out’ version of the distality problem is not a version of the distality problem at all. I conclude that Dretske's solution is preferable to Schulte's. (shrink)

I develop a distinction between two types of psychological hedonism. Inferential hedonism (or “I-hedonism”) holds that each person only has ultimate desires regarding his or her own hedonic states (pleasure and pain). Reinforcement hedonism (or “R–hedonism”) holds that each person's ultimate desires, whatever their contents are, are differentially reinforced in that person’s cognitive system only by virtue of their association with hedonic states. I’ll argue that accepting R-hedonism and rejecting I-hedonism provides a conciliatory position on the traditional altruism debate, and (...) that it coheres well with the neuroscientist Anthony Dickinson’s theory about the evolutionary function of hedonic states, the “hedonic interface theory.” Finally, I’ll defend R-hedonism from potential objections. (shrink)

At the beginning of the twentieth century, the French philosopher of science Edmond Goblot wrote three prescient papers on function and teleology. He advanced the remarkable thesis that functions are, as a matter of conceptual analysis, selected effects. He also argued that “selection” must be understood broadly to include both evolutionary natural selection and intelligent design. Here, I do three things. First, I give an overview of Goblot’s thought. Second, I identify his core thesis about function. Third, I argue that, (...) despite its ingenuity, Goblot’s expansive construal of function cannot be right. Still, Goblot deserves long-overdue credit for his work. (shrink)

In this paper investigates how natural deduction rules define connective meaning by presenting a new method for reading semantical conditions from rules called natural semantics. Natural semantics explains why the natural deduction rules are profoundly intuitionistic. Rules for conjunction, implication, disjunction and equivalence all express intuitionistic rather than classical truth conditions. Furthermore, standard rules for negation violate essential conservation requirements for having a natural semantics. The standard rules simply do not assign a meaning to the negation sign. Intuitionistic negation fares (...) much better. Not only do the intuitionistic rules have a natural semantics, that semantics amounts to familiar intuitionistic truth conditions. We will make use of these results to argue that intuitionistic connectives, rather than standard ones have a better claim to being the truly logical connectives. (shrink)

Quantified modal logic has reputation for complexity. Completeness results for the various systems appear piecemeal. Different tactics are used for different systems, and success of a given method seems sensitive to many factors, including the specific combination of choices made for the quantifiers, terms, identity, and the strength of the underlying propositional modal logic. The lack of a unified framework in which to view QMLs and their completeness properties puts pressure on those who develop, apply, and teach QML to work (...) with the simplest systems, namely those that adopt the Barcan Formulas and predicate logic rules for the quantifiers. In these systems, the quantifier ranges over a fixed domain of possible individuals, so advocates of these logics are sometimes called possibilists. A literature has grown up rationalizing the choice of possibilist logics despite ordinary intuitions that the resulting theorems are too strong.Williamson even takes the view that the complications to be faced within the weaker logics “are a warning sign of philosophical error”. It is the purpose of this paper to show that abandonment of the weaker QMLs is excessively fainthearted, since most QMLs can be given relatively simple formulations within one general framework. Given the straightforward nature of the systems and their completeness results, the purported complications evaporate, along with any philosophical warnings one might have associated with them. (shrink)

The purpose of this paper is to present a very versatile family of logical systems ofpositionalortopologicallogic. These systems—obtained by generalizing the existing systems of chronological logic—are to have a very general nature, capable of reflecting the characteristics of a wide range of logical systems, including not only chronological (alsotemporalortense) logic, but also what we may call locative or place logic, and even a logic of “possible worlds”.

The following considers the role of historical fidelity in habitat reconstruction efforts. To what extent should habitat reconstruction be guided by the goal of recreating some past state of a damaged ecosystem? I consider Sarkar’s “replacement argument,” which holds that, in most habitat reconstruction efforts, there is little justification for appealing to historical fidelity. I argue that Sarkar does not provide adequate grounds for deprecating historical fidelity relative to other natural values such as biodiversity or wild nature.

This paper explores a line of argument against the classical paradigm in cognitive science that is based upon properties of non-linear dynamical systems, especially in their chaotic and near-chaotic behavior. Systems of this kind are capable of generating information-rich macro behavior that could be useful to cognition. I argue that a brain operating at the edge of chaos could generate high-complexity cognition in this way. If this hypothesis is correct, then the symbolic processing methodology in cognitive science faces serious obstacles. (...) A symbolic description of the mind will be extremely difficult, and even if it is achieved to some approximation, there will still be reasons for rejecting the hypothesis that the brain is in fact a symbolic processor. (shrink)

Proponents of the language of thought (LOT) thesis are realists when it comes to syntactically structured representations, and must defend their view against instrumentalists, who would claim that syntactic structures may be useful in describing cognition, but have no more causal powers in governing cognition than do the equations of physics in guiding the planets. This paper explores what it will take to provide an argument for LOT that can defend its conclusion from instrumentalism. I illustrate a difficulty in this (...) project by discussing arguments for LOT put forward by Horgan and Tienson. When their evidence is viewed in the light of results in connectionist research, it is hard to see how a realist conception of syntax can be formulated and defended. (shrink)

Biological diversity - or ‘biodiversity’ - is the degree of variation of life within an ecosystem. It is a relatively new topic of study but has grown enormously in recent years. Because of its interdisciplinary nature the very concept of biodiversity is the subject of debate amongst philosophers, biologists, geographers and environmentalists. The Routledge Handbook of Philosophy of Biodiversity is an outstanding reference source to the key topics and debates in this exciting subject. Comprising twenty-three chapters by a team of (...) international contributors the _Handbook_ is divided into six parts: Historical and sociological contexts, focusing on the emergence of the term and early attempts to measure biodiversity _What is biodiversity? _How should biodiversity be defined? How can biodiversity include entities at the edge of its boundaries, including microbial diversity and genetically engineered organisms? _Why protect biodiversity? _What can traditional environmental ethics_ _contribute to biodiversity?_ _Topics covered include anthropocentrism, intrinsic value, and ethical controversies surrounding the economics of biodiversity _Measurement and methodology: _including decision-theory and conservation, the use of indicators for biodiversity, and the changing use of genetics in biodiversity conservation _Social contexts and global justice: _including conservation and community conflicts and biodiversity and cultural values _Biodiversity and other environmental values_: How does biodiversity relate to other values like ecological restoration or ecological sustainability? Essential reading for students and researchers in philosophy, environmental science and environmental studies, and conservation management, it will also be extremely useful to those studying biodiversity in subjects such as biology and geography. (shrink)

Natural deduction systems were motivated by the desire to define the meaning of each connective by specifying how it is introduced and eliminated from inference. In one sense, this attempt fails, for it is well known that propositional logic rules underdetermine the classical truth tables. Natural deduction rules are too weak to enforce the intended readings of the connectives; they allow non-standard models. Two reactions to this phenomenon appear in the literature. One is to try to restore the standard readings, (...) for example by adopting sequent rules with multiple conclusions. Another is to explore what readings the natural deduction rules do enforce. When the notion of a model of a rule is generalized, it is found that natural deduction rules express “intuitionistic” readings of their connectives. A third approach is presented here. The intuitionistic readings emerge when models of rules are defined globally, but the notion of a local model of a rule is also natural. Using this benchmark, natural deduction rules enforce exactly the classical readings of the connectives, while this is not true of axiomatic systems. This vindicates the historical motivation for natural deduction rules. One odd consequence of using the local model benchmark is that some systems of propositional logic are not complete for the semantics that their rules express. Parallels are drawn with incompleteness results in modal logic to help make sense of this. (shrink)

Scientists, philosophers, and even the lay public commonly accept that schizophrenia stems from a biological or internal ‘dysfunction.’ However, this assessment is typically accompanied neither by well-defined criteria for determining that something is dysfunctional nor empirical evidence that schizophrenia satisfies those criteria. In the following, a concept of biological function is developed and applied to a neurobiological model of schizophrenia. It concludes that current evidence does not warrant the claim that schizophrenia stems from a biological dysfunction, and, in fact, that (...) unusual neural structures associated with schizophrenia may have functional or adaptive significance. The fact that current evidence is ambivalent between these two possibilities (dysfunction versus adaptive function) implies that schizophrenia researchers should be much more cautious in using the ‘dysfunction’ label than they currently are. This has implications for both psychiatric treatment as well as public perception of mental disorders. (shrink)

Fodor and Pylyshyn (1988) argue that any successful model of cognition must use classical architecture; it must depend upon rule-based processing sensitive to constituent structure. This claim is central to their defense of classical AI against the recent enthusiasm for connectionism. Connectionist nets, they contend, may serve as theories of the implementation of cognition, but never as proper theories of psychology. Connectionist models are doomed to describing the brain at the wrong level, leaving the classical view to account for the (...) mind.This paper considers whether recent results in connectionist research weigh against Fodor and Pylyshyn's thesis. The investigation will force us to develop criteria for determining exactly when a net is capable of systematic processing. Fodor and Pylyshyn clearly intend their thesis to affect the course of research in psychology. I will argue that when systematicity is defined in a way that makes the thesis relevant in this way, the thesis is challenged by recent progress in connectionism. (shrink)

Intuitively, vagueness involves some sort of indeterminacy: if Plato is a borderline case of baldness, then there is no fact of the matter about whether or not he’s bald—he’s neither bald nor not bald. The leading formal treatments of such indeterminacy—three valued logic, supervaluationism, etc.—either fail to validate the classical theorems, or require that various classically valid inference rules be restricted. Here we show how a fully classical, yet indeterminist account of vagueness can be given within natural semantics, an alternative (...) semantics for classical proof theory. The key features of the account are: there is a single notion of truth—definite truth—and a single notion of validity; sentences can be true, false, or undetermined; all classical theorems and all classical inference rule are valid; the sorites argument is unsound; ‘definitely’ is treated as a meta-language predicate; higher-order vagueness is handled via semantic ascent. (shrink)

To assess Brette's proposal to expunge “coding” from the neuroscientist's lexicon, we must consider its origins. The coding metaphor is due largely to British nerve physiologist Edgar Adrian. I suggest two ways that the coding metaphor fueled his research. I conclude that the debate today should not be about the “truth” of the metaphor but about its continuing utility.

This paper is truly a joint effort and it could not have been written without the contribution of both authors. Garson, though, deserves credit (or blame) for first seeing the need for two kinds of quantifier scope, and also for devising essentials of the positive theory.

The binding problem is to explain how information processed by different sensory systems is brought together to unify perception. The problem has two sides. First, we want to explain phenomenal binding: the fact that we experience a single world rather than separate perceptual fields for each sensory modality. Second, we must solve a functional problem: to explain how a neural net like the brain links instances to types. I argue that phenomenal binding and functional binding require very different treatments. The (...) puzzle of phenomenal binding rests on a confusion and so can be dissolved. So only functional binding deserves explanation. The general solution to that problem is that information to be bound is arrayed along different dimensions. So sensory coding into separate topographic maps facilitates functional binding and there is no need based on the unity of perception for special mechanisms that bring "back together" information in different maps. (shrink)

I argue that despite the merits of Jefferson’s account of a brain disorder, which are many, the notion of function she deploys is unsuitable to the overall goals of that account. In particular, Jefferson accepts Cummins’ causal role theory of function and dysfunction. As the causal role view, in its standard elaborations, is wedded to human interests, goals, and values, it cannot serve as a value-neutral anchor for her hybrid “harm-dysfunction” account of disorder. I argue that the selected effects theory, (...) or some comparably value-neutral account, would serve her purposes better. (shrink)

A framework is presented in which the role ofdevelopmental rules in phenotypic evolution canbe studied for some simple situations. Usingtwo different implicit models of development,characterized by different developmental mapsfrom genotypes to phenotypes, it is shown bysimulation that developmental rules and driftcan result in directional phenotypic evolutionwithout selection. For both models thesimulations show that the critical parameterthat drives the final phenotypic distributionis the cardinality of the set of genotypes thatmap to each phenotype. Details of thedevelopmental map do not matter. If phenotypesare (...) randomly assigned to genotypes, the lastresult can also be proved analytically. (shrink)