To controlforceaccurately under a wide range of behavioral conditions, the central nervous system would either require a detailed, continuously updated representation of the state of each muscle (and the load against which each is acting) or else force feedback with sufficient gain to cope with variations in the properties of the muscles and loads. The evidence for force feedback with adequate gain or for an appropriate central representation is not sufficient to conclude that force is the major controlled variable in (...) normal limb movements.Morton's hypothesis, thatlengthis controlled by a follow-up servo, has a number of difficulties related to the delays, gains, variability, and specificity in feedback pathways comprising potential servo loops. However, experimental evidence is consistent with these pathways providing servo assistance for some movements produced by coactivation of α- and static γ-motoneurons. Dynamic γ-motoneurons may provide an additional input for adaptive control of different types of movements.The idea that feedback is used to compensate for changes in musclestiffnesshas received experimental support under static postural conditions. However, reflexes tend to increase rather than decrease the range of variation in muscle stiffness during some cyclic movements. Theoretical problems associated with the regulation of stiffness are also discussed. The possibilities of separate control systems forvelocityorviscosityare considered, but the evidence is either negative or lacking. I conclude that different physical variables can be controlled depending on the type of limb movement required. The concept of stiffness regulation is also useful under some conditions, but should probably be extended to the regulation of the visco-elastic properties (i.e., the mechanical impedance) of a muscle or joint. (shrink)

This volume is a collection of original essays by eminent philosophers written for R. B. Braithwaite's eightieth birthday to celebrate his work and teaching. In one way or another, all the essays reflect his central concern with the impact of science on our beliefs about the world and the responses appropriate to that. Together they testify to the signal importance of his contributions in areas of philosophy bearing on this concern: the philosophy of science, especially of the statistical sciences, theories (...) of belief and of probability, decision theory and games theory. This book, which includes a full bibliography of Professor Braithwaite's work, will interest advanced students and professionals in the fields of philosophy and psychology. (shrink)

This book is not a study of Plato's philosophy, but a contribution to the literary interpretation of the dialogues, through analysis of their formal structure, ...

R.G. Collingwood defined historical knowledge as essentially ‘scientific’, and saw the historian's task as the ‘re-enactment of past thoughts’. The author argues the need to go beyond Collingwood, first by demonstrating the authenticity of available evidence, and secondly, using Namier as an example, by considering methodology as well as epistemology, and the need to relate past thoughts to their present context. The ‘law of the consumption of time’ encourages historians to focus on landmark events, theories and generalisations, thus breaking from (...) Collingwood's emphasis on fidelity to past ideas and interpreting the past from the concepts of the present. This conflict can only be reconciled by the study of historiography. (shrink)

Visual research methods like photography and digital storytelling are increasingly used in health and social sciences research as participatory approaches that benefit participants, researchers, and audiences. Visual methods involve a number of additional ethical considerations such as using identifiable content and ownership of creative outputs. As such, ethics committees should use different assessment frameworks to consider research protocols with visual methods. Here, we outline the limitations of ethics committees in assessing projects with a visual focus and highlight the sparse knowledge (...) on how researchers respond when they encounter ethical challenges in the practice of visual research. We propose a situated approach in relation to visual methodologies that encompasses a negotiated, flexible approach, given that ethical issues usually emerge in relation to the specific contexts of individual research projects. Drawing on available literature and two case studies, we identify and reflect on nuanced ethical implications in visual research, like tensions between aesthetics and research validity. The case studies highlight strategies developed in-situ to address the challenges two researchers encountered when using visual research methods, illustrating that some practice implications are not necessarily addressed using established ethical clearance procedures. A situated approach can ensure that visual research remains ethical, engaging, and rigorous. (shrink)

E.R. Dodds’ 1959 edition of Plato’s Gorgias is a conventional treatment of this dialogue, aimed at audiences interested in close study of the text. Dodds himself regretted this outcome. He felt he had lost sight of an earlier goal, formulated at a time of political turmoil on the eve of WorldWar II, of using the Gorgias to bring out ‘both the resemblance and the difference between Plato’s situation and that of the intellectual today’. The present paper attempts to reconstruct that (...) goal, as it survives residually in his edition, surfaces in his The Greeks and the Irrational, and appears in some writings from the 1930s, particularly in unpublished lectures. Dodds did frequently juxtapose ancient and modern conceptions of the intellectual, and in a way that cast Plato in a positive light, as someone politically engaged and self-critical, and acutely sensitive, as Dodds himself was, to the political implications of social psychology. (shrink)

E.R. Dodds’ 1959 edition of Plato’s Gorgias is a conventional treatment of this dialogue, aimed at audiences interested in close study of the text. Dodds himself regretted this outcome. He felt he had lost sight of an earlier goal, formulated at a time of political turmoil on the eve of WorldWar II, of using the Gorgias to bring out ‘both the resemblance and the difference between Plato’s situation and that of the intellectual today’. The present paper attempts to reconstruct that (...) goal, as it survives residually in his edition, surfaces in his The Greeks and the Irrational, and appears in some writings from the 1930s, particularly in unpublished lectures. Dodds did frequently juxtapose ancient and modern conceptions of the intellectual, and in a way that cast Plato in a positive light, as someone politically engaged and self-critical, and acutely sensitive, as Dodds himself was, to the political implications of social psychology. (shrink)

R.G. Collingwood defined historical knowledge as essentially ‘scientific’, and saw the historian's task as the ‘re-enactment of past thoughts’. The author argues the need to go beyond Collingwood, first by demonstrating the authenticity of available evidence, and secondly, using Namier as an example, by considering methodology as well as epistemology, and the need to relate past thoughts to their present context. The ‘law of the consumption of time’ encourages historians to focus on landmark events, theories and generalisations, thus breaking from (...) Collingwood's emphasis on fidelity to past ideas and interpreting the past from the concepts of the present. This conflict can only be reconciled by the study of historiography. (shrink)

In this paper a formalized logic of propositions, PA1, is presented. It is proven consistent and its relationships to traditional logic, to PM ([15]), to subjunctive (including contrary-to-fact) implication and to the “paradoxes” of material and strict implication are developed. Apart from any intrinsic merit it possesses, its chief significance lies in demonstrating the feasibility of a general logic containing theprinciple of subjunctive contrariety, i.e., the principle that ‘Ifpwere true thenqwould be true’ and ‘Ifpwere true thenqwould be false’ are incompatible.

The concept of energy, the premier concept of physics and indeed of all science, is here investigated from the standpoint of its early historical origin and the philosophical implications thereof. The fundamental assumption is made that the root of the concept is the notion of invariance or constancy in the midst of change. Salient points in the development of this idea are presented from ancient times up to the publication of Lagrange'sMécanique Analytique (1788).

Marcus Aurelius, Roman emperor from 161 to 180 A.D., is renowned for his just rule and long frontier wars. But his lasting fame rests on his Meditations, a bedside book of reflections and self-admonitions written during his last years, that provide unique insights into the mind of an ancient ruler and contain many passages of pungent epigram and poetic imagery. This study is designed to make the Meditations more accessible to the modern reader. Rutherford carefully explains the historical and philosophical (...) background, charts the main themes and tendencies of Marcus's thought, and relates stylistic detail to the intellectual and moral outlook of the author. His goal is to define Marcus's aims, attitudes, and styles more precisely and restore his work to the position it held in the past, that of a spiritual classic which can be read and enjoyed by people who are not professional scholars. (shrink)

The question of whether or not children may be used as subjects in non-therapeutic research projects has generated a great deal of debate and received answers varying from 'no, never' to 'yes, if societal interests are served'. It has been claimed that a Kantian, deontological ethics would necessarily rule out such research, since valid consent would be impossible. The present paper gives a deontological argument for allowing children to be subjects in certain types of research.

It is the aim of this paper to examine certain aspects of a point of view which has attracted much attention in physical methodology. This is the standpoint known as operationalism. We wish to discuss its significance in the construction and interpretation of physical theories.The essential meaning of operationalism in physics is that physical concepts should be defined in terms of actual physical operations. On this view there is no meaning to a concept unless it represents an operation which can (...) be performed in the laboratory. Thus the term “pressure of a gas” signifies nothing until an operation is described which constitutes the measurement of pressure. When one thinks of pressure one must think. of some actual apparatus, such as, for example, some glass and rubber tubing and some mercury and certain operations performed using these until finally one gets a pointer reading which one calls the pressure of the gas. The same stand is taken with respect to length, time, velocity, acceleration, temperature, etc. (shrink)

In the fourteenth century William of Occam in the course of his attack on the medieval scholastic philosophy enunciated his famous “razor”: Entia non sunt multiplicanda praeter necessitatem. This is the classic claim for the description of nature in terms of the minimum possible number of fundamental concepts. It was presumably so recognized by Newton in the third book of his “Principia” in 1687 when he wrote: “We are to admit no more causes of natural things than such as are (...) both true and sufficient to explain their appearances. To this purpose the philosophers say that Nature does nothing in vain, and more is in vain when less will serve; for Nature is pleased with simplicity and affects not the pomp of superfluous causes.”. (shrink)

In 2035 global egg demand will have risen 50% from 1985. Because we are not able to tell in the egg whether it will become a male or female chick, billons of one day-old male chicks will be killed. International research initiatives are underway in this area, and governments encourage the development of an alternative with the goal of eliminating the culling of day-old male chicks. The Netherlands holds an exceptional position in the European egg trade, but is also the (...) only country in the European Union where the downside of the egg sector, the practice of killing day-old male chicks, is a recurrent subject of societal debate. ‘Preventing the killing of young animals’ and ‘in ovo sex determination’ are the two alternative approaches available to solve this problem. It is clear that both approaches solve the problem of killing day-old male chicks, either by keeping them alive or by preventing them from living, but they also raise a lot of new animal welfare-related dilemmas. A thorough analysis was undertaken of these dilemmas and the results are presented in this article. The analysis resulted in an ethical framework based on the two main approaches in bioethics: a consequentialist approach and a deontological approach. This ethical framework was used to develop an online survey administered to ascertain Dutch public opinion about these alternative approaches. The results show that neither alternative will be fully accepted, or accepted by more than half of Dutch society. However, the survey does provide an insight into the motives that are important for people’s choice: food safety and a good treatment of animals. Irrespective of the approach chosen, these values should be safeguarded and communicated clearly. (shrink)

Changes being introduced to deregulate the Dutch health care system after decades of extensive state control are to be welcomed, and will in future require consumers to be ‘well‐informed, cost‐conscious and assertive patients, who are aware of their responsibility for their own health.’ R.B. Kool MD, PhD and E.J.J.M. Kimman PhD are attached to the Department of Business Ethics in the Faculty of Economics and Econometrics at The Free University, P.O. Box 7161, 10107 MC Amsterdam.

Two years ago in two articles in a thematic issue of this journal the three of us engaged in a critique of principlism. In a subsequent issue, B. Andrew Lustig defended aspects of principlism we had criticized and argued against our own account of morality. Our reply to Lustig's critique is also in two parts, corresponding with his own. Our first part shows how Lustig's criticisms are seriously misdirected. Our second and philosophically more important part picks up on Lustig's challenge (...) to us to show that our account of morality is more adequate than principlism. In particular we show that recognition of morality as public and systematic enables us to provide a far better description of morality than does principlism. This explains why we adopt the label “Dartmouth Descriptivism.”. (shrink)

Changes being introduced to deregulate the Dutch health care system after decades of extensive state control are to be welcomed, and will in future require consumers to be ‘well‐informed, cost‐conscious and assertive patients, who are aware of their responsibility for their own health.’ R.B. Kool MD, PhD and E.J.J.M. Kimman PhD are attached to the Department of Business Ethics in the Faculty of Economics and Econometrics at The Free University, P.O. Box 7161, 10107 MC Amsterdam.

K.J. Devlin has extended Jensen's construction of a model ofZFC andCH without Souslin trees to a model without Kurepa trees either. We modify the construction again to obtain a model with these properties, but in addition, without Kurepa trees inccc-generic extensions. We use a partially defined ◊-sequence, given by a fine structure lemma. We also show that the usual collapse ofκ Mahlo toω 2 will give a model without Kurepa trees not only in the model itself, but also inccc-extensions.