We consider the simple case of a nonrelativistic charged harmonic oscillator in one dimension, to investigate how to take into account the radiation reaction and vacuum fluctuation forces within the Schrödinger equation. The effects of both zero-point and thermal classical electromagnetic vacuum fields, characteristic of stochastic electrodynamics, are separately considered. Our study confirms that the zero-point electromagnetic fluctuations are dynamically related to the momentum operator p=−i ℏ ∂/∂ x used in the Schrödinger equation.

We make a brief review of the Kramers escape rate theory for the probabilistic motion of a particle in a potential well U(x), and under the influence of classical fluctuation forces. The Kramers theory is extended in order to take into account the action of the thermal and zero-point random electromagnetic fields on a charged particle. The result is physically relevant because we get a non-null escape rate over the potential barrier at low temperatures (T → 0). It is found (...) that, even if the mean energy is much smaller than the barrier height, the classical particle can escape from the potential well due to the action of the zero-point fluctuating fields. These stochastic effects can be used to give a classical interpretation to some quantum tunneling phenomena. Relevant experimental data are used to illustrate the theoretical results. (shrink)

‘Mysticism means to isolate the eternal from the originated.’ This is not my definition of the word ‘mysticism’ but that of the founder of the ‘orthodox’ school of Muslim mysticism, Al-Junayd of Baghdad who flourished in the ninth century a.d . In actual fact it is not a definition of mysticism at all but of the Arabic word tawḥīd which means primarily ‘the affirmation of unity’; and that surely is an essential ingredient of any form of mysticism: it is the (...) affirmation through personal experience of unity either absolutely or in some qualified sense. (shrink)

As everyone knows, since the end of the Second World War there has been a sensational revival of interest in the non-Christian religions particularly in the United States and in this country. The revival has taken two forms, the one popular, the other academic. The first of these has turned almost exclusively to Hindu and Buddhist mysticism and can be seen as an energetic reaction against the dogmatic and until very recently rigid structure of institutionalised Christianity and a search for (...) a lived experience of the freedom of the spirit which is held to be the true content of mysticism, obscured in Christianity by the basic dogma of a transcendent God, the ‘wholly Other’ of Rudolf Otto and his numerous followers, but wholly untrammelled by any such concept in the higher reaches of Vedanta and Buddhism, particularly in its Zen manifestation. On the academic side the picture is less clear. There is, of course, the claim that the study of religion, like any other academic study, must be subjected to and controlled by the same principles of ‘scientific’ objectivity to which the other ‘arts’ subjects have been subjected, to their own undoing. But even here there would seem to be a bias in favour of the religions of India and the Far East as against Islam, largely, one supposes, in response to popular demand. (shrink)

Hawthorne and Magidor's criticisms of the model of presupposition and assertion that I have used and defended are all based on a rejection of some transparency or introspection of assumptions about speaker presupposition. This response to those criticisms aims first to clarify, and then to defend, the required transparency assumptions. It is argued, first, that if the assumptions are properly understood, some prima facie problems for them do not apply, second, that rejecting the assumptions has intuitively implausible consequences, and third, (...) that the 'margin of error' argument against the principle of positive introspection has a false premiss. The paper concludes with a response to a criticism of what Hawthorne and Magidor call 'the uniformity principle' that is used in the model to explain some pragmatic phenomena. (shrink)

Aim To study the views of people in a largely Muslim country, Kuwait, of the acceptability of a life-ending action such as physician-assisted suicide (PAS). Method 330 Kuwaiti university students judged the acceptability of PAS in 36 scenarios composed of all combinations of four factors: the patient's age (35, 60 or 85 years); the level of incurability of the illness (completely incurable vs extremely difficult to cure); the type of suffering (extreme physical pain or complete dependence) and the extent to (...) which the patient requests a life-ending procedure, euthanasia or PAS (no request, some form of request, repeated requests). In all scenarios, the patients were women who were receiving the best possible care. The ratings were subjected to cluster analysis and analyses of variance. Results Five clusters were found. For 44%, PAS was always very unacceptable, no matter what the circumstances. For 23%, it was unacceptable, but less so if the patient was older or requested it repeatedly. For 16%, it was unacceptable if the patient was young but was acceptable if the patient was elderly. For 5%, it was unacceptable if the patient had extreme pain but was acceptable if completely dependent. For 11%, it was unacceptable if the patient did not request it but acceptable if she did. Conclusion The majority of the Kuwaiti university students opposed PAS either categorically or with a slight variation according to circumstances. Nonetheless, a minority approved of PAS in some cases, particularly when the patient was elderly. (shrink)

The problem that confronts us when we try to compare the structure of discourse and explanation in different domains of knowledge is that no one is an insider in more than one field, and insider information is essential. An observer who is not immersed in the practice of a particular scholarship and who wants to understand it is at the mercy of the practitioners. Yet those practitioners are themselves mystified by a largely unexamined communal myth of how scholarship is carried (...) on. R. G. Collingwood, although primarily a philosopher, was immersed in the community of historians and understood how history is done, so that he has had an immense influence on our ideas about historiography. Every historian knows The Idea of History.1 He was also a metaphysician, yet his influence on scientists’ understanding of nature, and of science, has been nil, and it is a rare scientist indeed who has ever heard of Collingwood or read The Idea of Nature.2 Collingwood’s views of the structure of science had to be constructed in large part from the elaborate fictions created by scientists and by an earlier generation of philosophers and historians of science who participated in the Baconian myth of the hypothetical-deductive scheme. 1. See R. G. Collingwood, The Idea of History .2. See Collingwood, The Idea of Nature . R. C. Lewontin is Alexander Agassiz Professor at Harvard University. He is an experimental and theoretical evolutionary geneticist who has also worked extensively on epistemological issues in biology. He is the author of The Genetic Basis of Evolutionary Change and, with Richard Levins, of The Dialectical Biologist . His current research concerns the nature of genetic variation among individuals within species. (shrink)

We have examined only a few of the basic questions about causal inference that result from Reichenbach's two principles. We have not considered what happens when the probability distribution is a mixture of distributions from different causal structures, or how unmeasured common causes can be detected, or what inferences can reliably be drawn about causal relations among unmeasured variables, or the exact advantages that experimental control offers. A good deal is known about these questions, and there is a good deal (...) more to find out. (shrink)

Who are you, God? -- Who made you, God? -- I want to find you, God -- I can't see you, God -- How much do you know, God? -- Where is truth, God? -- The shadow doesn't turn -- The just judge -- The invincible power -- Can I trust you, God? -- The love that will not let us go -- The name above all names.

At the library of the Ecole Normale Supérieure in Paris, the dissertations in the Humanities are arranged in chronological order. A single glance suffices to tell us that this classification by years coincides almost exactly with a classification by bulk. As we pass along through time, year by year, the volumes grow thicker; pamphlets merge imperceptibly into modest books, these into larger books, these in turn into weighty tomes; until finally we come across works embracing several volumes, each volume imposing (...) in its own right. The explanation is simple: every author is normally led to consider the opinions of his predecessors in the same field or in neighbouring fields; these opinions he discusses, contests, approves, or amends; and finally this leads to the growth in bulk, gradual but unlimited, so evident on the shelves at the library. (shrink)