A growing number of young people with disabilities is pursuing university education. Available research on the impact of Information and Communication Technologies on this matter has mainly focused on assistive technologies and their compensatory role for the adjustment of this group of students to the tertiary setting. However, limited research has looked at the role played by digital technologies such as social media and mobile devices in the transition to university, a critical period of change for all students but more (...) challenging for those with impairments. This paper presents the findings of an empirical study that investigated the experiences of students with vision impairments aged 18 to 24 who were transitioning to a New Zealand university. The findings draw from observations, a researcher diary, focus groups, individual interviews, and data from social media. The study found that new technologies play several enabling roles that help students to manage diverse transition challenges. These roles not only include aspects such as impairment compensation, communication, information, and learning but also support arrangement, collaboration, and social connection and participation. By incorporating in the analysis the potential of digital tools, the article updates and expands the understanding of the role of ICTs in higher education from experiences and views of young people with vision impairments. (shrink)

This article introduces Transition 2.0, a paradigm shift designed to study and support students with disabilities' transition to higher education. Transition 2.0 is the result of a qualitative study about how a group of young people with vision impairments used digital technologies for their transition to university. The findings draw from observations, a researcher diary, focus groups, individual interviews, and data from social media. The article discusses a conventional view of transition, referred to here as Transition 1.0, which has (...) dominated disability-related research and service provision in higher education. It counters this view by further developing the conceptual framework for Transition 2.0. The findings expand current conceptual approaches to transition by incorporating in the analysis the role played by digital tools such as social media and mobile devices. They also provide a new lens through which to study and understand student engagement in higher education. (shrink)

Viewing strategies are strategies used to support visual information processing. These strategies may differ between children with cerebral visual impairment, children with ocular visual impairment, and children with normal vision since visual impairment might have an impact on viewing behavior. In current visual rehabilitation practice a variety of strategies is used without consideration of the differences in etiology of the visual impairment or in the spontaneous viewing strategies used. This systematic scoping review focuses on viewing (...) strategies used during near school-based tasks like reading and on possible interventions aimed at viewing strategies. The goal is threefold: creating a clear concept of viewing strategies, mapping differences in viewing strategies between children with ocular visual impairment, children with CVI and children with normal vision, and identifying interventions that can improve visual processing by targeting viewing strategies. Four databases were used to conduct the literature search: PubMed, Embase, PsycINFO and Cochrane. Seven hundred and ninety-nine articles were screened by two independent reviewers using PRISMA reporting guidelines of which 30 were included for qualitative analysis. Only five studies explicitly mentioned strategies used during visual processing, namely gaze strategies, reading strategies and search strategies. We define a viewing strategy as a conscious and systematic way of viewing during task performance. The results of this review are integrated with different attention network systems, which provide direction on how to design future interventions targeting the use of viewing strategies to improve different aspects of visual processing. (shrink)

ObjectivesMany older adults with visual impairment also have significant hearing loss. The aim was to investigate the effectiveness of a newly developed Dual Sensory Loss protocol on communication and wellbeing of older persons with DSL and their communication partners in the Netherlands and Belgium.MethodsParticipants and their communication partners were randomized in the “DSL-protocol” intervention group or a waiting-list control group. The intervention took 3 to 5 weeks. Occupational therapists focused on optimal use of hearing aids, home-environment modifications and effective (...) communication strategies. The primary outcome was the Communication Strategies domain of the Communication Profile for the Hearing Impaired. Secondary outcomes measured in participants were the Low Vision Quality Of Life Adjustment subscale, the Center for Epidemiological Studies - Depression Scale, De Jong Gierveld Loneliness Scale and the Fatigue Assessment Scale. The Hearing Handicap and Disability Inventory - Reaction of Others subscale and the Care-related Quality of Life - 7 Dimensions was measured in communication partners. Measurements were taken at baseline and 3-month follow-up. Linear mixed models were used to analyze effects between groups over time for every outcome measure.ResultsIntention-to-treat analyses showed a significant effect of the DSL-protocol on the use of verbal strategies in favor of the control group, however, this effect was non-significant after adjustment for confounding. Effect sizes of other outcomes varied between −0.23 [−0.57, 0.12] and 0.30 [−0.05, 0.64]. The LMM showed a significant effect on the HHDI-Reaction of others scale in favor of communication partners in the treatment group, however, the effect did not remain significant at a 0.01 significance level and the effect size was very small and non-significant 0.12, 95% CI [−0.27 to 0.51]. Adjusted analyses did not reveal treatment effects.ConclusionThe DSL-protocol did not clearly contribute to the enhancement of communication and wellbeing in DSL-patients. Possible reasons for the lack of effects are OTs not being comfortable giving advice on communication and psychosocial issues or the short-term treatment and follow-up period. Further study is warranted to find out how the protocol may be adapted or whether it is necessary to involve mental healthcare professionals.Clinical Trial Registrationwww.ClinicalTrials.gov, identifier NTR2843. (shrink)

Objective: Individually, vision and hearing impairments have been linked to higher levels of anxiety and depression. We investigated the effect of dual sensory impairment in a large representative sample of Spanish adults. Methods: Data from a total of 23,089 adults from the Spanish National Health Survey 2017 were analyzed. Self-reported difficulty of seeing and hearing, and depression and chronic anxiety were analyzed. Multivariable logistic regression was assessed for difficulty with vision alone, hearing alone and with difficulty with (...) both, adjusting for gender, age, marital status, living as a couple, education, smoking, alcohol consumption, BMI, physical activity, use of glasses/contact lenses, and hearing aid. Results: Visual difficulty, hearing difficulty, and dual difficulties were all associated with significantly higher odds for depression and for chronic anxiety. Dual sensory difficulty was associated with higher odds ratios for depression and anxiety when compared to either impairment alone. Conclusion: Dual sensory difficulty is associated with significantly higher odds of anxiety and depression when compared to either vision or hearing difficulty alone. Appropriate interventions are needed to address any reversible causes of vision and hearing as well as anxiety and depression in people in these specific groups. (shrink)

Falls are frequent in Myotonic Dystrophy type 1, but the pathophysiology of the balance impairment needs further exploration in this disease. The current work aims to provide a richer understanding of DM1 imbalance. Standing balance in 16 patients and 40 controls was tested in two posturographic tests. In the Sensory Organization Test, standstill balance was challenged by combining visual and environmental conditions. In the “react” test, reflexes induced by sudden shifts in the support base were studied. Oscillations of the (...) body centre of mass were measured. In the SOT, COM sway was larger in patients than controls in any condition, including firm support with eyes open. On sway-tuned support, COM oscillations when standing with closed eyes were larger in patients than controls even after taking into account the oscillations with eyes open. In the “react” paradigm, balance reflexes were delayed in patients. Results in both experimental paradigms are consistent with leg muscle weakness. This, however, is not a sufficient explanation. The SOT test highlighted that patients rely on vision more than controls to maintain static balance. Consistently enough, evidence is provided that an impairment of proprioceptive and vestibular systems contributes to falls in DM1. Rehabilitation programs targeted at reweighting sensory systems may be designed to improve safe mobility in DM1. (shrink)

The ‘man born blind restored to light’ was one of the foundational myths of the Enlightenment, according to Foucault. With ophthalmic surgery in its infancy, the fascination by the sighted with blindness and what the blind might ‘see’ after sight restoration remained largely speculative. Was being blind, as Descartes once remarked, like ‘seeing with the hands’? Did evidence from early cataract operations begin to resolve epistemological debates about the relationship between vision and touch in the newly sighted, such as (...) the famous ‘Molyneux Question’ posed by William Molyneux to John Locke? More recently, how have autobiographical accounts of blind and vision impaired writers and poets advanced the sighted public’s understanding of blind subjectivity? -/- Through an unfolding historical, philosophical and literary narrative that includes Locke, Molyneux and Berkeley in Britain, and Diderot, Voltaire and Buffon in France, this book explores how the Molyneux Question and its aftermath has influenced attitudes towards blindness by the sighted, and sensory substitution technologies for the blind and vision impaired, to this day. (shrink)

We review the hypothesis that the brain uses a generative model to explain the causes of sensory inputs, using prediction schemes that operate based upon assimilation of time-series sensory data. We put this hypothesis in the context of psychopathology, in particular, schizophrenia's positive symptoms. Building upon work of Helmholtz and upon theories in computational cognitive processing, we hypothesize that delusions in schizophrenia can be explained in terms of false inference. An impairment in inferring appropriate information from the sensory input (...) reflects upon the ability to assess the environment and predict outcomes. Although the inference mechanism likely involves both conscious and unconscious processes, we hypothesize that the trigger of delusions may lie within the unconscious neural pathways. A collection of computational predictive codes have been proposed for modeling perception. We discuss two examples, which may be eligible as substrates for intuitive coding. We argue that failure of the psychotic patient to choose the correct computational scheme, or the optimal range of parameters, may readily lead to an altered reconstruction of the object and false inference, feeding into the delusion mechanism. We finally propose using these models in conjunction with cognitive and imaging data, in order to obtain more testable predictions. (shrink)

GY, an extensively studied human hemianope, is aware of salient visual events in his cortically blind field but does not call this ''vision.'' To learn whether he has low-level conscious visual sensations or whether instead he has gained conscious knowledge about, or access to, visual information that does not produce a conscious phenomenal sensation, we attempted to image process a stimulus s presented to the impaired field so that when the transformed stimulus T(s) was presented to the normal hemifield (...) it would cause a sensation similar to that caused by s in the impaired field. While degradation of contrast, spatio-temporal filtering, contrast reversal, and addition of smear and random blobs all failed to match the response to a flashed bar sf, moving textures of low contrast were accepted to match the response to a moving contrast-defined bar, sm. Orientation and motion direction discrimination of the perceptually matched stimuli [sm and T(sm)] was closely similar. We suggest that the existence of a satisfactory match indicates that GY has phenomenal vision. (shrink)

IntroductionCerebral visual impairment results from damage to cerebral visual processing structures. It is the most common cause of pediatric visual impairment in developed countries and rising in prevalence in developing nations. There is currently limited understanding on how neurologic, developmental, and ophthalmic factors predict outcome for pediatric CVI.MethodA retrospective manual chart review of pediatric CVI patients seen at the tertiary pediatric hospital neurology and neuro-ophthalmology service between 2010 and 2019 was conducted. Patients were stratified into severity groups, and (...) followed over time to identify outcome predictors. Collected baseline characteristics included perinatal, genetic, developmental, and neurologic history, along with neuroimaging and fundoscopic findings on examination. Longitudinal data collected included age, seizure control, and type of therapy received. Linear mixed-effect models were used for longitudinal CVI grade outcome analysis.ResultsA total of 249 individuals spanning 779 patient visits were identified. Mean age at diagnosis was 18.8 ± 16.8 months. About 64.3% were born at term age. Perinatal history revealed hypoxic ischemic encephalopathy in 16.5%, intraventricular hemorrhage in 11.6%, and seizures in 21.7%. At presentation, 60.3% had a diagnosis of cerebral palsy and 84.7% had developmental delay. Among all subjects, 78.6% had epilepsy; 33.8% had an epileptic encephalopathy, with spasms/hypsarrhythmia being most common. Abnormal neuroimaging was present in 93.8%. Genetic anomalies were present in 26.9%. Baseline visual examination revealed no blink-to-light in 24.5%; only BTL in 34.5%, fixation/tracking in 26.5%, and optokinetic drum follow in 14.4%. Longitudinal data analysis showed that perinatal history of HIE, a positive epilepsy history, using multiple epilepsy medications, cerebral palsy, and abnormal fundoscopic findings were all negatively associated with CVI grade change over time. After controlling for significant confounders, receiving any type of therapy [early childhood intervention, physical and occupational therapy, refractive error correction or glasses] was significantly associated with longitudinal improvement in CVI grade compared to patients who did not receive any therapy, with glasses yielding the largest benefit.ConclusionThis study offers extensive insights into neurologic, developmental and ophthalmologic features in patients with moderate to severe CVI. In concordance with previous findings, aspects of perinatal history and epilepsy/seizure control may help inform severity and prognosis in the general neurology or ophthalmology clinic. Conversely, these aspects, as well as genetic and specific epilepsy traits may alert vision health care providers in the clinic to pursue visual evaluation in at-risk individuals. Longitudinal follow-up of CVI patients showed that interventional therapies demonstrated vision function improvement greater than no therapy and maturational development. (shrink)

Background: There is limited research on brain lesions in children with cerebral visual impairment of heterogeneous etiologies and according to associated subtyping and vision dysfunctions. This study was part of a larger project establishing data-driven subtypes of childhood CVI according to visual dysfunctions. Currently there is no consensus in relation to assessment, diagnosis and classification of CVI and more information about brain lesions may be of potential diagnostic value.Aim: This study aimed to investigate overall patterns of brain lesions (...) and associations with level of visual dysfunction and to compare the patterns between the classification subgroups in children with CVI.Methods: School-aged children with CVI received ophthalmological and neuro-psychological/developmental assessments to establish CVI-related subtyping. Other pediatric information was collected from medical records. MRI scans were coded according to a semi-quantitative template including brain regions and summed for total scores. Non-parametric analyses were conducted.Results: 28 children had clinical brain MRI scans available [44% of total sample, Group A n = 16, Group B n = 12]. Total brain scores ranged between 0 and 18 and were widespread across regions. 71 per cent had post-geniculate visual pathway damage. The median total brain and hemisphere scores of Group B were higher than subgroup A but differences did not reach statistical significance. No statistically significant associations were found between brain scores and vision variables.Conclusion: This study found a spread of lesions across all regions on the brain scans in children with congenital CVI. The majority had damage in the postgeniculate visual pathways and visual cortex region suggesting this is an area of interest and potentially informative for diagnosis. However the subtyping classification did not show differences in number or region of lesions though the trend was higher toward Group B. This study confirms the complex diffuse and variable nature of brain lesions in children with congenital CVI, many of whom have other neurological impairments. (shrink)

Despite the importance of knowing the cognitive capabilities of children with neurodevelopmental conditions, less than one-third of children with cerebral palsy participate in standardized assessments. Globally, approximately 50% of people with cerebral palsy have an intellectual disability and there is significant risk for domain-specific cognitive impairments for the majority of people with cerebral palsy. However, standardized cognitive assessment tools are not accessible to many children with cerebral palsy, as they require manual manipulation of objects, verbal response and/or speeded response. As (...) such, standardised assessment may result in an underestimation of abilities for children with significant motor and/or speech impairment. The overall aim of the project is to examine and compare the psychometric properties of standardised cognitive assessment tools that have been accommodated for use with either a switch device or eye-gaze control technologies, with the specific aims to: Examine the psychometric properties of accommodated assessment tools by comparing the performance of typically developing children on six cognitive assessment tools administered via standardised versus accommodated administration; Describe and compare the performance and user experience of children with cerebral palsy on six accommodated cognitive assessments administered via switch or eye-gaze control technologies. Secondary aims are to: Describe the completion rates and time to complete assessments of participants in each group; Within the group with cerebral palsy, examine the effects of condition-specific characteristics and demographics on participation. This protocol paper describes a two-phase validation and acceptability study that utilizes a mixed-model design. This study will collect concurrent data from 80 typically developing children and 40 children with cerebral palsy, who use switch or eye-gaze control technology as alternate access communication methods. The set of instruments will measure receptive vocabulary, fluid reasoning, sustained attention, vision perception, visuospatial working memory and executive functions. Data analyses will be conducted using SPSS v. 25 and R v 4.1.0. SPSS Sample Power 3 was used for power computation and allows for a 10% drop out rate. Quantitative descriptive statistics, measurement agreement data plotting, bivariate and multiple regressions analysis will be conducted using appropriate methods. (shrink)

Rod photoreceptors are among the most sensitive light detectors in nature. They achieve their remarkable sensitivity across a wide variety of species through a number of essential adaptations: a specialized cellular geometry, a G‐protein cascade with an unusually stable receptor molecule, a low‐noise transduction mechanism, a nearly perfect effector enzyme, and highly evolved mechanisms of feedback control and receptor deactivation. Practically any change in protein expression, enzyme activity, or feedback control can be shown to impair photon detection, either by decreasing (...) sensitivity or signal‐to‐noise ratio, or by reducing temporal resolution. Comparison of mammals to amphibians suggests that rod outer‐segment morphology and the molecules and mechanism of transduction may have evolved together to optimize light sensitivity in darkness, which culminates in the extraordinary ability of these cells to respond to single photons at the ultimate limit of visual perception. (shrink)

In this book Gerald Vision argues for a new causal theory, one that engages provocatively with direct realism and makes no use of a now discredited subjectivism.

In Veritas, Gerald Vision defends the correspondence theory of truth -- the theory that truth has a direct relationship to reality -- against recent attacks, and critically examines its most influential alternatives. The correspondence theory, if successful, explains one way in which we are cognitively connected to the world; thus, it is claimed, truth -- while relevant to semantics, epistemology, and other studies -- also has significant metaphysical consequences. Although the correspondence theory is widely held today, Vision points (...) to an emerging orthodoxy in philosophy that claims that truth as such carries no significant weight in philosophical explanations. He devotes much of the book to a criticism of that outlook and to a less vulnerable formulation of the correspondence theory.Vision defends the correspondence theory by both presenting evidence for correspondence and examining the claims made by such alternative theories as deflationism, minimalism, and pluralism. The techniques of the argument are thoroughly analytic, but the problem confronted is broadly humanistic. The question examined -- how we, as thinking beings, are connected to and manage to cope in a world that was not designed for our comfort or convenience -- is more likely to be raised by continentalists, but is approached here with the tools of clarity and precision more highly prized in analytic philosophy. The book seeks to avoid both the obscurantism that infects much continental thought and the overly technical concerns and methodology that limit the interest of much work in analytic philosophy. It thus provides a rigorous but largely nontechnical treatment of the topic that will be of interest not only to readers familiar with philosophy but also to those with a background in literary theory and linguistics. (shrink)

In virtue of its form [‘I am here’] must be true on any occasion on which [it is] asserted, and yet the proposition it expresses on each occasion [is] contingent. Intuitively, [‘I am here now’] is deeply, and in some sense universally, true. One need only understand the meaning of [it] to know that it cannot be uttered falsely. The sentence ‘I am here’ has the peculiar property that whenever I utter it, it is bound to be true. Even if (...) I am lost and do not know where I am, I can bravely say ‘I am here’, and know that I am expressing a truth. (shrink)

The evidence of blindsight is occasionally used to argue that we can see things, and thus have perceptual belief, without the distinctive visual awareness accompanying normal sight; thereby displacing phenomenality as a component of the concept of vision. I maintain that arguments to this end typically rely on misconceptions about blindsight and almost always ignore associated visual (or visuomotor) pathologies relevant to the lessons of such cases. More specifically, I conclude, first, that the phenomena very likely do not result (...) from dissociations within a single system, but from the interaction of evolutionarily distinct, if interacting, systems; second, that a closer study of spared motor abilities indicates that verbal responses of patients result not from degraded vision but from proprioception; and, finally, above chance verbal responses, being forced guesses, are not tentative beliefs and cannot become beliefs just by training patients to have more confidence in their responses. (shrink)

I INTRODUCTION - THE TOPIC EXPLAINED 1 GENERAL DIFFERENCES From its inception to the present, philosophy may be viewed as a series of struggles between ...

In " Re-Emergence" he explores the question of conscious properties arising from brute, unthinking matter, making the case that there is no equally plausible non-emergent alternative.

In specifying the sensory evidence for perceptual belief, thinkers have either chosen a common perceptual idiom or have invented one of their own as a starting-point for their enquiries. It is becoming clearer that the choice harbours crucial, often disputable, assumptions. I compare two sorts of constructions, a variety of propositional ones and an objectual one, and I argue that the objectual idiom is indispensable in order to explain how a perceptual belief can arise out of what is not already (...) a belief. This has implications not only for the question of how belief is generated from perceptual evidence, but also for various other controversies. I discuss two of these implications: the character of inferences from evidence, and basic belief. (shrink)

Parmenides didn't mention reference as such, but if he had he would have undoubtedly agreed with the philosophers who nowadays hold what is called "the axiom of existence": that one can only refer to what exists. The sources of possible support for this view are examined and rejected. Primary support for the axiom is given by two sorts of argument; one concerning quantification, the other summarizing a standard Parmenidean puzzle. Weaknesses in both are exposed. Finally, the relations between the axiom (...) and connected claims about predication and truth are probed, and an attempt is made to determine the limits of the mutual support these claims give one another. (shrink)

Parmenides didn't mention reference as such, but if he had he would have undoubtedly agreed with the philosophers who nowadays hold what is called "the axiom of existence": that one can only refer to what exists. The sources of possible support for this view are examined and rejected. Primary support for the axiom is given by two sorts of argument; one concerning quantification, the other summarizing a standard Parmenidean puzzle. Weaknesses in both are exposed. Finally, the relations between the axiom (...) and connected claims about predication and truth are probed, and an attempt is made to determine the limits of the mutual support these claims give one another. (shrink)

Under the title of ‘the axiom of existence’, hereafter, John R. Searle has reduced to compact dictum a view to which many philosophers subscribe: ‘Whatever is referred to must exist’. In this paper I shall offer two major arguments against adopting, at least on certain assumptions. There have been a number of defenses of, among them those arguing that it is fundamental to any systematic philosophy of language or logic. With the exception of discussing some of Searle's remarks in part (...) Ill of this paper I shall not comment on any of these defenses. (shrink)

Although a number of truth theorists have claimed that a deflationary theory of ‘is true’ needs nothing more than the uniform implication of instances of the theorem ‘the proposition that p is true if and only if p ’, reflection shows that this is inadequate. If deflationists can’t support the instances when replacing the biconditional with ‘because’, then their view is in peril. Deflationists sometimes acknowledge this by addressing, occasionally attempting to deflate, ‘because’ and ‘in virtue of’ formulas and their (...) close relatives. I examine what I take to be the most promising deflationist moves in this direction and argue that they fail. (shrink)

From the popular view that the property of truth adds nothing not already inherent in its bearers it has been inferred that classical theories of truth are thereby refuted. Taking as representative a version of deflationism based on a certain way of interpreting the Tarskian schema convention T–and popularly called "disquotational"–I argue that the view is beset by fatal difficulties. These include: an unavoidable awkwardness in handling indexicals; an inability to accept anything more than a too anemic notion of a (...) truth condition, leaving it defenseless against clearly inadequate alternatives; and an incapacity to show that its characteristic biconditional can support any acceptable dependency claims (made evident by replacing the biconditional with 'because'). Finally, were there no predicate on the order of 'is true', this would not annihilate the property of being true or the current grounds for philosophical inquiries about it. This is an important clue to why deflationary approaches in general are dead ends. (shrink)

A broad, though not unanimous, consensus among commentators is that the later Wittgenstein subscribes to a redundancy conception of truth. I reject that interpretation. No doubt much depends on what is meant by a redundancy theory. But once even mildly plausible versions of that view are isolated a review of the relevant texts shows that the evidence for that interpretation collapses. Moreover, the redundancy interpretation is at odds with guiding prescriptions in the post‐1932 corpus. Wittgenstein doesn’t hold that truth can (...) be defined or characterized thinly, as redundancy theorists propose, but that it isn’t susceptible to any such generic treatment. (shrink)

Emergentism is generally viewed as a non‐materialist alternative to physicalism, although the exceptionally tolerant may count it as consistent with their physicalism. It disarms the threat of Causal Exclusion. The popular conception of explored emergentism is played off against two forms, including physical states and tokens of conscious states (c‐states). Emergentism competes not only with physicalism, but also with panpsychism. Panpsychism is the view that all matter has a conscious aspect. Panpsychism (and its various forms) suffers from several problems. This (...) chapter summarizes a few of the major ones. It scratches the surface of the issues separating emergentism and physicalism, on the one hand, and emergentism and panpsychism, on the other. However, perhaps enough has been divulged to show that emergentism is a live option, a serious candidate when trying to discover a c‐state's place in concrete reality. (shrink)

A broad, though not unanimous, consensus among commentators is that the later Wittgenstein subscribes to a redundancy conception of truth. I reject that interpretation. No doubt much depends on what is meant by a redundancy theory. But once even mildly plausible versions of that view are isolated a review of the relevant texts shows that the evidence for that interpretation collapses. Moreover, the redundancy interpretation is at odds with guiding prescriptions in the post‐1932 corpus. Wittgenstein doesn’t hold that truth can (...) be defined or characterized thinly, as redundancy theorists propose, but that it isn’t susceptible to any such generic treatment. (shrink)

A broad, though not unanimous, consensus among commentators is that the later Wittgenstein subscribes to a redundancy conception of truth. I reject that interpretation. No doubt much depends on what is meant by a redundancy theory. But once even mildly plausible versions of that view are isolated a review of the relevant texts shows that the evidence for that interpretation collapses. Moreover, the redundancy interpretation is at odds with guiding prescriptions in the post‐1932 corpus. Wittgenstein doesn’t hold that truth can (...) be defined or characterized thinly, as redundancy theorists propose, but that it isn’t susceptible to any such generic treatment. (shrink)