Recent magnetic resonance imaging (MRI) and pathological studies have indicated that axonal loss is a major contributor to disease progression in multiple sclerosis. 1 H magnetic resonance spectroscopy (MRS), through measurement of N -acetyl aspartate (NAA), a neuronal marker, provides a unique tool to investigate this. Patients with primary progressive multiple sclerosis have few lesions on conventional MRI, suggesting that changes in normal appearing white matter (NAWM), such (...) as axonal loss, may be particularly relevant to disease progression in this group. To test this hypothesis NAWM was studied with MRS, measuring the concentration of N -acetyl derived groups (NA, the sum of NAA and N -acetyl aspartyl glutamate). Single-voxel MRS using a water-suppressed PRESS sequence was carried out in 24 patients with primary progressive multiple sclerosis and in 16 age-matched controls. Ratios of metabolite to creatine concentration (Cr) were calculated in all subjects, and absolute concentrations were measured in 18 patients and all controls. NA/Cr (median 1.40, range 0.86–1.91) was significantly lower in NAWM in patients than in controls (median 1.70, range 1.27–2.14; P = 0.006), as was the absolute concentration of NA (patients, median 6.90 mM, range 4.62–10.38 mM; controls, median 7.77 mM, range 6.60–9.71 mM; P = 0.032). There was no significant difference in the absolute concentration of creatine between the groups. This study supports the hypothesis that axonal loss occurs in NAWM in primary progressive multiple sclerosis and may well be a mechanism for disease progression in this group. (shrink)
I offer a new theory of faultless disagreement, according to which truth is absolute (non-relative) but can still be non-objective. What's relative is truth-aptness: a sentence like ‘Vegemite is tasty’ (V) can be truth-accessible and bivalent in one context but not in another. Within a context in which V fails to be bivalent, we can affirm that there is no issue of truth or falsity about V, still disputants, affirming and denying V, were not at fault, since, in their context (...) of assertion V was bivalent. This theory requires a theory of assertion that is a form of cognitive expressivism. (shrink)
Essentialism is widely regarded as a mistaken view of biological kinds, such as species. After recounting why (sections 2-3), we provide a brief survey of the chief responses to the “death of essentialism” in the philosophy of biology (section 4). We then develop one of these responses, the claim that biological kinds are homeostatic property clusters (sections 5-6) illustrating this view with several novel examples (section 7). Although this view was first expressed 20 years ago, and has received recent discussion (...) and critique, it remains underdeveloped and is often misrepresented by its critics (section 8). (shrink)
There is a wide-spread belief amongst theorists of mind and language. This is that in order to understand the relation between language, thought, and reality we need a theory of meaning and content, that is, a normative, formal science of meaning, which is an extension and theoretical deepening of folk ideas about meaning. This book argues that this is false, offering an alternative idea: The form of a theory that illuminates the relation of language, thought, and reality is a theory (...) of language agency. In a nutshell, the theory of language agency is a theory of competence, without being a theory of understanding or grasping rules. It is a theory of cognitive structure and language production. This theory distils all there is to say about language, thought, and reality. It does not supplement a theory of truth-conditions or semantic norms. It is not the explanation of how a speaker, qua cognitive system causally embedded in a larger reality, is able to use a language with some pre-existing semantic characterization. There is no pre-existing semantic characterization. Nevertheless, there are facts of meaning, as good as any other facts. The dissolution of the theory of meaning is accompanied by another disappearance. That is the disappearance of metaphysical questions in a number of domains. Once we complete the theory of language agency, then just as theoretical questions about meaning disappear, certain theoretical questions about existence disappear. Having provided a theory of the language agency for talk of meaning, fact, property, relation, and proposition, there is no question left over about what meanings, facts, properties, relations, and propositions are. There is no theory to be given of their natures. This is not because they have primitive irreducible natures. Rather it is because, in a sense to be clarified in this work, they lack natures. I call this approach to language agency Global Expressivism. That is because it generalizes some of the insights brought to the study of value-language by expressivists. However, it removes these insights from the clouding affects of attempting to make expressivism a semantic theory. Expressivism about value fails as a semantic theory of value talk. However, global expressivism can succeed as a theory of all talk because it is not a semantic theory but a theory of language agency, wherein the theory of meaning is replaced by a theory of talk about meaning. (shrink)
The Tidal Model represents a significant alternative to mainstream mental health theories, emphasizing how those suffering from mental health problems can benefit from taking a more active role in their own treatment. Based on extensive research, The Tidal Model charts the development of this approach, outlining the theoretical basis of the model to illustrate the benefits of a holistic model of care which promotes self-management and recovery. Clinical examples are also employed to show how, by exploring rather than ignoring a (...) client's narrative, practitioners can encourage the individual's greater involvement in the decisions affecting their assessment and treatment. The Tidal Model 's comprehensive coverage of the theory and practice of this model will be of great use to a range of mental health professionals and those in training in the fields of mental health nursing, social work, psychotherapy, clinical psychology and occupational therapy. (shrink)
A far-reaching and influential view in evolutionary biology claims that species are cohesive units held together by gene flow. Biologists have recognized empirical problems facing this view; after sharpening the expression of the view, we present novel conceptual problems for it. At the heart of these problems is a distinction between two importantly different concepts of cohesion, what we call integrative and response cohesion. Acknowledging the distinction problematizes both the explanandum of species cohesion and the explanans of gene flow that (...) are central to the view we discuss. We conclude by tracing four broader implications for the study and conceptualization of species. (shrink)
Over the last 2,300 years or so, many philosophers have believed that species are individuated by essences that are at least in part intrinsic. Psychologists tell us most folks also believe this view. But most philosophers of biology have abandoned the view, in light of evolutionary conceptions of species. In defiance, Michael Devitt has attempted in this journal to resurrect a version of the view, which he calls Intrinsic Biological Essentialism. I show that his arguments for the resurrection fail, and (...) I identify challenges that face anyone wishing to defend Intrinsic Biological Essentialism. *Received February 2009; revised September 2009. †To contact the author, please write to: Philosophy Department, University of Wisconsin–Madison, 5185 Helen C. White Hall, 600 North Park Street, Madison, WI 53706; e‐mail: mjbarker2@wisc.edu. (shrink)
Emotivist, or non-descriptivist metaethical theories hold that value-statements do not function by describing special value-facts, but are the mere expressions of naturalistically describable motivational states of (valuing) agents. Non-descriptivism has typically been combined with the claim that value-statements are non-cognitive: they are not the manifestations of genuine belief states. However, all the linguistic, logical and phenomenological evidence indicates that value-statements are cognitive. Non-descriptivism then has a problem. Horgan and Timmons propose to solve it by boldly combining a non-descriptivist thesis about (...) value with the claim that value-judgements are after all cognitive. Although possessing many attractive features, I argue that their framework fails to deliver the promised results; it suffers from a certain internal incoherence about the concept of content and mis-characterizes the descriptive/non-descriptive content distinction required by nondescriptivism. (shrink)
This paper brings needed clarity to the influential view that species are cohesive entities held together by gene flow, and then develops an empirical argument against that view: Neglected data suggest gene flow is neither necessary nor sufficient for species cohesion. Implications are discussed. ‡I'm grateful to Rob Wilson, Alex Rueger and Lindley Darden for important comments on earlier drafts, and to Joseph Nagel, Heather Proctor, Ken Bond, members of the DC History and Philosophy of Biology reading group, and audience (...) members at the November 2006 meeting of the PSA, for helpful comments or discussion. Social Sciences and Humanities Research Council of Canada fellowship 752-2005-1208 supported research. †To contact the author, please write to: Philosophy Department, University of Wisconsin–Madison, 5185 Helen C. White Hall, 600 North Park Street, Madison, WI 53706; e-mail: mjbarker2@wisc.edu. (shrink)
This work provides an overview of traditional and contemporary ethical perspectives and critically examines a range of ethical and moral challenges present in ...
We argue for a new conventionalism about many kinds of evolutionary groups, including clades, cohesive units, and populations. This rejects a consensus, which says that given any one of the many legitimate grouping concepts, only objective biological facts determine whether a collection is such a group. Surprisingly, being any one kind of evolutionary group typically depends on which of many incompatible values are taken by suppressed variables. This is a novel pluralism underlying most any one group concept, rather than a (...) familiar pluralism claiming many concepts are legitimate. Consequently, we must help biological facts determine grouphood, even when given a single grouping concept. (shrink)
Living things are often plastic during their early development and are moulded by the environment. Many human fetuses have to adapt to a limited supply of nutrients, and in doing so they permanently change their physiology and metabolism. These programmed changes may be the origins of a number of diseases in later life, including coronary heart disease, stroke, diabetes and hypertension.
Individuals are a prominent part of the biological world. Although biologists and philosophers of biology draw freely on the concept of an individual in articulating both widely accepted and more controversial claims, there has been little explicit work devoted to the biological notion of an individual itself. How should we think about biological individuals? What are the roles that biological individuals play in processes such as natural selection (are genes and groups also units of selection?), speciation (are species individuals?), and (...) organismic development (do genomes code for organisms)? Much of our discussion here will focus on organisms as a central kind of biological individual, and that discussion will raise broader questions about the nature of the biological world, for example, about its complexity, its organization, and its relation to human thought. (shrink)
This paper suggests several summa genera for the various meanings of intentio in Aquinas and briefly outlines the genera of cognitive intentiones. It presents the referential and existential nature of intentions of harm or usefulness as distinguished from external sensory or imaginary forms in light of Avicenna’s threefold sensory abstraction. The paper offers a terminological clarification regarding the quasi-immaterial existential status of intentions. Internal sensory intentions account for a way in which one perceives something, as is best seen in light (...) of the distinction between formal and material objects. Against the imagist account of intentions that denies the memorative power an immanent object, it shows that the memorative’s proper and immediate object is the intention of the past, while its extrinsic mediate object is the imaginary phantasm. (shrink)
One of the liveliest debates about cognition concerns whether our cognition sometimes extends beyond our brains and bodies. One party says Yes, another No. This paper shows that debate between these parties has been epistemologically confused and requires reorienting. Both parties frequently appeal to empirical considerations and to extra-empirical theoretical virtues to support claims about where cognition is. These things should constrain their claims, but cannot do all the work hoped. This is because of the overlooked fact, uncovered in this (...) paper, that we could never distinguish the rival views empirically or by typical theoretical virtues. I show this by drawing on recent work on testing, predictive accuracy, and theoretical virtues. The recommendation to emerge is that we step back from debate about where cognition is, to the epistemology of what cognition is. (shrink)
One form of argument from analogy is identified and Stephen Barker's remarks about a second kind of argument from analogy, non-inductive (and non-deductive) argument from analogy, are used as a springboard to identify a second form. That form is then refined, explained, exemplified, and related to the first form. It is argued that there is a spectrum of different forms of argument from analogy, with the two forms identified being end points on the spectrum. Except in terms of form, (...) however, there is no reason to speak of two different kinds of argument from analogy. (shrink)
