Implicitly, Wynn's target article starts from the transformational definition of symmetry. Unlike his suggestion, this traditional definition and the recent holographic definition are relevant to the discussion on the cognitive evolution of visual symmetries. These definitions reveal underlying properties and, thereby, they support the natural selection hypothesis. The holographic definition even agrees with an indirect test of this hypothesis.

This paper was presented at the Second World Congress on Logic and Religion on the sub-topic of logics vis-à-vis illogicalities in religion. It deals with fourteenth-century-logician Thomas Manlevelt’s Ockhamist approach to logic (the ars vetus, strictly speaking) and its ontological outcome: rejection of the existence of substance. Although God, the Trinity, the Blessed Virgin, the Antichrist and the consecrated host keep popping up within the domain of logic, it is argued that Manlevelt kept clear water between logic and theology. Things (...) divine, and especially the transubstantiation of the consecrated host, do however play a crucial role in the development of his idea of the non-existence of substance. It is suggested that this might imply the miraculous nature of the whole universe. (shrink)

We identify two aspects of the problem of maintaining perceptual stability despite an observer's eye movements. The first, visual direction constancy, is the (egocentric) stability of apparent positions of objects in the visual world relative to the perceiver. The second, visual position constancy, is the (exocentric) stability of positions of objects relative to each other. We analyze the constancy of visual direction despite saccadic eye movements.Three information sources have been proposed to enable the visual system to achieve stability: the structure (...) of the visual field, proprioceptive inflow, and a copy of neural efference or outflow to the extraocular muscles. None of these sources by itself provides adequate information to achieve visual direction constancy; present evidence indicates that all three are used.Our final question concerns how information processing operations result in a stable world. The three traditionally suggested means have been elimination, translation, or evaluation. All are rejected. From a review of the physiological and psychological evidence we conclude that no subtraction, compensation, or evaluation need take place. The problem for which these solutions were developed turns out to be a false one. We propose a “calibration” solution: correct spatiotopic positions are calculated anew for each fixation. Inflow, outflow, and retinal sources are used in this calculation: saccadic suppression of displacement bridges the errors between these sources and the actual extent of movement. (shrink)

Background: Debates over legalisation of physician-assisted suicide or euthanasia often warn of a “slippery slope”, predicting abuse of people in vulnerable groups. To assess this concern, the authors examined data from Oregon and the Netherlands, the two principal jurisdictions in which physician-assisted dying is legal and data have been collected over a substantial period.Methods: The data from Oregon comprised all annual and cumulative Department of Human Services reports 1998–2006 and three independent studies; the data from the Netherlands comprised all four (...) government-commissioned nationwide studies of end-of-life decision making and specialised studies. Evidence of any disproportionate impact on 10 groups of potentially vulnerable patients was sought.Results: Rates of assisted dying in Oregon and in the Netherlands showed no evidence of heightened risk for the elderly, women, the uninsured , people with low educational status, the poor, the physically disabled or chronically ill, minors, people with psychiatric illnesses including depression, or racial or ethnic minorities, compared with background populations. The only group with a heightened risk was people with AIDS. While extralegal cases were not the focus of this study, none have been uncovered in Oregon; among extralegal cases in the Netherlands, there was no evidence of higher rates in vulnerable groups.Conclusions: Where assisted dying is already legal, there is no current evidence for the claim that legalised PAS or euthanasia will have disproportionate impact on patients in vulnerable groups. Those who received physician-assisted dying in the jurisdictions studied appeared to enjoy comparative social, economic, educational, professional and other privileges. (shrink)

The King Report on Corporate Governance (1994) evoked unprecedented interest in corporate governance in South Africa. This does not mean that corporate governance was not an issue of concern before the release of this historical report. To the contrary, corporate governance in its broader sense has been at stake since the inception of the first publicly owned companies in South Africa. This article intends to give an overview of corporate governance in South Africa. It starts by making a distinction between (...) broad and narrow conceptions of corporate governance. Before applying this distinction to the practice of corporate governance in South Africa, a brief overview of the corporate landscape in South Africa is provided. Then the South African situation with regard to broad and narrow corporate governance respectively is analysed. The article ends with a discussion of the review of corporate governance that currently is in the making in South Africa. Throughout the article both the financial and ethical dimensions of corporate governance is attended to. (shrink)

The King Report on Corporate Governance (1994) evoked unprecedented interest in corporate governance in South Africa. This does not mean that corporate governance was not an issue of concern before the release of this historical report. To the contrary, corporate governance in its broader sense has been at stake since the inception of the first publicly owned companies in South Africa. This article intends to give an overview of corporate governance in South Africa. It starts by making a distinction between (...) broad and narrow conceptions of corporate governance. Before applying this distinction to the practice of corporate governance in South Africa, a brief overview of the corporate landscape in South Africa is provided. Then the South African situation with regard to broad and narrow corporate governance respectively is analysed. The article ends with a discussion of the review of corporate governance that currently is in the making in South Africa. Throughout the article both the financial and ethical dimensions of corporate governance is attended to. (shrink)

Background: Although genetic research into Alzheimer disease (AD) is increasing, the ethical aspects of this kind of research and the differences between ethical issues related to genetic and non-genetic research into AD have not yet received much attention. Objectives: (1) To identify and compare the five ethical issues considered most important by surveyed expert panellists in non-genetic and genetic AD research and (2) to compare our empirical findings with ethical issues in genetic research in general as described in the literature. (...) Method: A modified Delphi study in two rounds Results: Genetic and non-genetic research into AD generated an approximately equal number of topics with a considerable overlap. Different priorities in the ethics of both types of research were found. Genetic research raised new topics such as “confidentiality of genetic information” and “implications of research for relatives” which changes the impact and application of existing ethical topics such as “informed consent” and is judged to have more impact on both individuals and society. A difference with the results of more theoretical approaches on ethical aspects related to AD research was also found. Conclusions: Different priorities are given to ethical issues in genetic and non-genetic research. These arise partly because genetic research causes unique and new questions, mostly related to the position of family members and the status of and access to genetic information. Differences found between the results of our empirical study and the more theoretical literature, suggest an additional value for empirical research in medical ethics. (shrink)

The phenomena referred to by the term attention were not discovered by scientific psychology. They were discovered and described within philosophy and gently handed over to the emerging academic psychology of the nineteenth century. The main contributors and contributions to the delineation and construction of attention as an empirical phenomenon and a topic for theorizing were Aristotle, who noticed that not all that reaches the senses is clearly perceived; Augustine, who interpreted attention as an effort of the soul; Descartes, who (...) distinguished active attention from passive attention; and Leibniz, who discussed the relation between attention, perception, and consciousness. (For further information on attention's philosophical past the reader is referred to Neumann's (in press) brief history of this philosophical past that is badly in need of an English translation.). (shrink)

The explanatory gap refers to the lack of concepts for understanding “how it is that . . . a state of consciousness comes about as a result of irritating nervous tissue.” By assuming that there are colours in the outside world, Block needlessly widens this gap and Lycan and Kitcher simply fail to see the gap. When such assumptions are abandoned, an unnecessary and incomprehensible constraint disappears. It then becomes clear that the brain can use its own neural language for (...) representing aspects of the outside world. While this may not close the gap, it becomes clearer where we need new concepts. (shrink)

Everybody knows the phenomena summarized with the term attention: concentration, focalization, limitation, selection, and intensification. The explanation of these phenomena is, however, a different matter. Problems easily arise with regard towhathas to be explained and with regard to thestyleof explanation. A problem of the first kind is the “methodology of ‘bad focus’”: the explanation starts with and is fixated on an intuitively striking but nonessential behavioral feature or cognitive achievement. A problem of the second kind is a “virtus dormitiva” explanation: (...) the explanation starts with emphasizing one aspect of the observed phenomena, the emphasized aspect receives an interesting and suggestive name, and that name with its connotations is used as a concept in the explanation. At the start of contemporary, behavior-based, information processing psychology, avirtus dormitivaexplanation infiltrated the functional accounts of the phenomena of attention; the empirical observation that people show performance limitations was translated into the theoretical concept of a communication channel with a limited capacity. That limited capacity notion became the core concept in what can be called the standard theory of attention. This standard theory of attention faced severe difficulties in explaining the guidance of attention by the information processor's goals and intentions. Subsequent modifications, concerned with removing these difficulties, revealed that selection, guided by goals and intentions, is the essential behavioral feature and that the observed performance limitations are a result of this selection. So, the limited capacity theorizing was not only plagued by avirtus dormitivaexplanation, it also suffered from the methodology of bad focus. (shrink)

Everybody knows the phenomena summarized with the term attention: concentration, focalization, limitation, selection, and intensification . The explanation of these phenomena is, however, a different matter. Problems easily arise with regard towhathas to be explained and with regard to thestyleof explanation. A problem of the first kind is the “methodology of ‘bad focus’”: the explanation starts with and is fixated on an intuitively striking but nonessential behavioral feature or cognitive achievement. A problem of the second kind is a “virtus dormitiva” (...) explanation: the explanation starts with emphasizing one aspect of the observed phenomena, the emphasized aspect receives an interesting and suggestive name, and that name with its connotations is used as a concept in the explanation. At the start of contemporary, behavior-based, information processing psychology, avirtus dormitivaexplanation infiltrated the functional accounts of the phenomena of attention; the empirical observation that people show performance limitations was translated into the theoretical concept of a communication channel with a limited capacity. That limited capacity notion became the core concept in what can be called the standard theory of attention. This standard theory of attention faced severe difficulties in explaining the guidance of attention by the information processor's goals and intentions. Subsequent modifications, concerned with removing these difficulties, revealed that selection, guided by goals and intentions, is the essential behavioral feature and that the observed performance limitations are a result of this selection. So, the limited capacity theorizing was not only plagued by avirtus dormitivaexplanation, it also suffered from the methodology of bad focus. (shrink)