Thought experiments analogous to those discussed by Landau and Peierls are studied in the framework of a manifestly covariant relativistic quantum theory. It is shown that momentum and energy can be arbitrarily well defined, and that the drifts induced by measurement in the positions and times of occurrence of events remain within the (stable) spread of the wave packet in space-time. The structure of the Newton-Wigner position operator is studied in this framework, and it is shown that an analogous time (...) operator can be constructed which satisfies the canonical commutation relation with the energy E but does not commute (due to the presence of a time drift term) with the momentum p. The resulting commutation relation is used as a mathematical basis for the derivation of the Landau-Peierls relation Δt Δp≳ħ/c. (shrink)

The dynamical equations of relativistic quantum mechanics prescribe the motion of wave packets for sets of events which trace out the world lines of the interacting particles. Electromagnetic theory suggests thatparticle world line densities be constructed from concatenation of event wave packets. These sequences are realized in terms of conserved probability currents. We show that these conserved currents provide a consistent particle and antiparticle interpretation for the asymptotic states in scattering processes. The relation between current conservation and unitarity is used (...) to establish relations between pair production and annihilation amplitudes and scattering. The discrete symmetriesC, T, P are studied and it is shown that no Dirac sea (for fermions where such a construction is possible, or bosons where it is not) is required for consistency of the theory. These currents, furthermore, represent the discrete symmetries in a way consistent with their interpretation as particle currents. (shrink)

Recently, in the framework of a relativistic quantum theory with invariant evolution parameter, solutions have been found for the two-body bound state, whose mass spectrum agrees with the nonrelativistic Schrödinger energy spectrum. In this paper, we study the radiative transitions of these states in the dipole approximation and find that the selection rules are identical with those of the usual nonrelativistic theory, expressed in a manifestly covariant form. In addition to the transverse and longitudinal polarizations of the nonrelativistic theory, we (...) find a “scalar” transition, induced by the relative time coordinate, which is of the same type as the longitudinal transition, expressing the Lorentz covariance of the theory. (shrink)

The contemporary view of the fundamental role of time in physics generally ignores its most obvious characteric, namely its flow. Studies in the foundations of relativistic mechanics during the past decade have shown that the dynamical evolution of a system can be treated in a manifestly covariant way, in terms of the solution of a system of canonical Hamilton type equations, by considering the space-time coordinates and momenta ofevents as its fundamental description. The evolution of the events, as functions of (...) a universal invariant world, or historical, time, traces out the world lines that represent the phenomena (e.g., particles) which are observed in the laboratory. The positions in time of each of the events, i.e., the time of their potential detection, are, in this framework, controlled by this universal parameter τ, the time at which they are generated (and may proceed in the positive or negative sense). We find that the notion of thestate of a system requires generalization; at any given τ, it involves information about the system at timest(τ) ≠ τ. The correlation of what may be measured att(τ) with what is generated at τ is necessarily quite rigid, and is related covariantly to the spacelike correlations found in interference experiments. We find, furthermore, that interaction with Maxwell electromagnetism leads back to a static picture of the world, with no real evolution. As a consequence of this result, and the requirement of gauge invariance for the quantum mechanical evolution equation, we conclude that electromagnetism is described by a pre-Maxwell field, whose τ-integral (or asymptotic behavior as τ → ∞) may be identified with the Maxwell field. We therefore consider the world of events in space time, interacting through τ-dependent pre-Maxwell fields, as far as electrodynamics is concerned, as the objective dynamical reality. Our perception of the world, through laboratory detectors and our eyes, are based onintegration over τ over intervals sufficiently large to obtain an aposteriori description of the phenomena which coincides with the Maxwell theory. Fundamental notions, such as the conservation of charge, rest on this construction. The decomposition of the common notion of time into two essentially different aspects, one associated with an unvarying flow, and the second with direct observation subject to dynamical modification, has profound philosophical consequences, of which we are able to explore here only a few. (shrink)

Gauge invariance of a manifestly covariant relativistic quantum theory with evolution according to an invariant time τ implies the existence of five gauge compensation fields, which we shall call pre-Maxwell fields. A Lagrangian which generates the equations of motion for the matter field (coinciding with the Schrödinger type quantum evolution equation) as well as equations, on a five-dimensional manifold, for the gauge fields, is written. It is shown that τ integration of the equations for the pre-Maxwell fields results in the (...) usual Maxwell equations with conserved current source. The analog of the O (3, 1) symmetry of the usual Maxwell theory is found to be O (3, 2) or O (4, 1), depending on the space-time Fourier spectrum of the field. We argue that the structure that is relevant to the description of radiation in interaction with matter evolving in a timelike sense is that of O (3, 2). The noncovariant form of the field equations is given; there are two fields of electric type and one (divergenceless) magnetic type field. The Noether currents are studied, and some remarks are made on second quantization. (shrink)

R F Dearden; Theory and Practice in Education, Journal of Philosophy of Education, Volume 14, Issue 1, 30 May 2006, Pages 17–29, https://doi.org/10.1111/j.1467-.

This provocative collection of essays written by the influential Greek scholar E. R. Dodds between 1929 and 1971. represents the wide range of his literary and philosophical interests. Insightful and learned, the essays combine profound scholarship with the lucid humanity of a teacher awareof the special value of Greek studies in the modern world.

I defend the suggestion that the rational probability in the Sleeping Beauty paradox is one third. The reasoning in its favour is familiar: for every heads-waking, there are two tails-wakings. To complete the defense, I rebut the reasoning which purports to justify the competing suggestion – that the correct probability is half – by undermining its premise, that no new information has been received.

R S Downie; Professions and Professionalism, Journal of Philosophy of Education, Volume 24, Issue 2, 30 May 2006, Pages 147–159, https://doi.org/10.1111/j.1467-.

In the face of environmental crises such as climate change, pollution and biodiversity loss—which all adversely impact on health—Gils-Schmidt and Salloch explore whether physicians can be justified in taking climate issues into account in clinical care.1 While their approach centres on the ‘climate-sensitive’ decisions, physicians can carry out on the micro-level of clinical decision-making, they encourage further discussions on how climate-related issues can be included across different levels of decision-making in healthcare. We propose a list of tasks and a model (...) to assist with navigating the range of factors and structural elements an environmentally sensitive ethics must address. Stephen Gardiner’s notion of a perfect moral storm is central to understanding these issues.2 Gardiner describes how a perfect moral storm occurs in the centre of three overlapping conditions for human action and policymaking in the face of climate change. This storm is driven by: (1) a lack of interest among current generations to meet global needs and accommodate the well-being of future generations, (2) a lack of ecological concerns for other parts of nature than humans and (3) weak ethical and political theories and institutions shaping policy decisions on issues with severe implications across borders and generations. Moreover, these conditions are embedded in the existing, complex world of ethically unjustified power imbalances and social injustice. The growing awareness of healthcare’s climate footprint has amplified and accelerated global, grassroots action to make healthcare more environmentally friendly. This includes incorporating environmental impacts into quality improvement methodologies, building communities of practice to explore how to make …. (shrink)

What kind of knowledge is medical knowledge? Can medicine be explained scientifically? Is disease a scientific concept, or do explanations of disease depend on values? What is ‘evidence-based’ medicine? Are advances in neuroscience bringing us closer to a scientific understanding of the mind? The nature of medicine raises fundamental questions about explanation, causation, knowledge and ontology – questions that are central to philosophy as well as medicine. In this book Paul R. Thompson and Ross E. G. Upshur introduce the fundamental (...) issues in philosophy of medicine for those coming to the subject for the first time. They introduce and explain the following key topics: Understanding the physician-patient relationship: the phenomenology of the medical encounter. Models and theories in biology and medicine: what role do theories play in medicine? Are they similar to scientific theories? Randomised controlled trials: can scientific experiments be replicated in clinical medicine? What are the philosophical criticisms levelled at RCTs? The concept of evidence in medical research: what do we mean by ‘Evidence-based medicine?’ Should all medicine be based on evidence? Causation in medicine What do advances in neuroscience reveal about the relationship between mind and body? Defining health and disease: are explanations of disease objective or do they depend on values? Evolutionary medicine: what is the role of evolutionary biology in understanding medicine? Is it relevant? Extensive use of empirical examples and case studies is made throughout the book. These include debates about smoking and cancer, the use of placebos in randomised controlled trials and controversies about research into the causes of HIV and autism. This is an indispendable introduction to those teaching philosophy of medicine and philosophy of science. (shrink)

R W K Paterson; Towards an Axiology of Knowledge, Journal of Philosophy of Education, Volume 13, Issue 1, 30 May 2006, Pages 91–100, https://doi.org/10.1111/j.1.

This original and lively book explores Greek ideas about health and disease and their influence on Greek thought. Fundamental issues such as causation and responsibility, purification and pollution, mind-body relations and gender differences, authority and the expert and who can challenge them, reality and appearances, good government, happiness, and good and evil themselves are deeply implicated. Using the evidence not just from Greek medical theory and practice but also from epic, lyric, tragedy, historiography, philosophy, and religion, G. E. R. Lloyd (...) offers the first comprehensive account of the influence of Greek thought about health and disease on the Greek imagination. (shrink)

R S Downie; Professions and Professionalism, Journal of Philosophy of Education, Volume 24, Issue 2, 30 May 2006, Pages 147–159, https://doi.org/10.1111/j.1467-.

R K Elliott; Education, Love of One’s Subject, and the Love of Truth, Journal of Philosophy of Education, Volume 8, Issue 1, 30 May 2006, Pages 135–153, https:/.

R K Elliott; Education, Love of One’s Subject, and the Love of Truth, Journal of Philosophy of Education, Volume 8, Issue 1, 30 May 2006, Pages 135–153, https:/.

R K Elliott; Versions of Creativity, Journal of Philosophy of Education, Volume 5, Issue 2, 30 May 2006, Pages 139–152, https://doi.org/10.1111/j.1467-9752.1971.

R W K Paterson; Towards an Axiology of Knowledge, Journal of Philosophy of Education, Volume 13, Issue 1, 30 May 2006, Pages 91–100, https://doi.org/10.1111/j.1.

R S Peters; Education and Justification, Journal of Philosophy of Education, Volume 11, Issue 1, 30 May 2006, Pages 28–38, https://doi.org/10.1111/j.1467-9752.1.

Published here for the first time in paperback is much of a final and long-anticipated work on philosophy of history by the renowned Oxford philosopher, historian, and archaeologist R. G. Collingwood. The original text of this uncompleted work was only recently discovered in the archives of Oxford University Press. Also found there were two conclusions written by Collingwood for lectures which were eventually revised and published as The Idea of Nature, but which have relevance to his philosophy of history as (...) well. These pieces are included in this volume, accompanied by further short writings by Collingwood on historical knowledge and inquiry, selected from previously unpublished manuscripts held at the Bodleian Library, Oxford. All these writings, besides containing entirely new ideas, discuss further many of the issues which Collingwood is famous for having raised in The Idea of History and in his Autobiography.A lengthy editorial introduction sets these writings in their context, and discusses philosophical questions to which they give rise. The editors also consider why Collingwood left The Principles of History unfinished at his death, and what significance should be attached to the fact that it contains no reference to one of his best-known ideas: that of historical understanding as re-enactment. This volume will be a significant publication not just in Collingwood studies but in philosophy of history generally. (shrink)

EDITED BY SLAVENKO ŠLJUKIĆBOOK SYMPOSIUM ON KENNETH R. WESTPHAL’S HOW HUME AND KANT RECONSTRUCT NATURAL LAW.

R F Dearden; Theory and Practice in Education, Journal of Philosophy of Education, Volume 14, Issue 1, 30 May 2006, Pages 17–29, https://doi.org/10.1111/j.1467-.

R K Elliott; The Concept of Development: A Reply to Professor Hamlyn, Journal of Philosophy of Education, Volume 9, Issue 1, 30 May 2006, Pages 40–48, https://d.

R K Elliott; The Concept of Development: A Reply to Professor Hamlyn, Journal of Philosophy of Education, Volume 9, Issue 1, 30 May 2006, Pages 40–48, https://d.

R K Elliott; The Concept of Development: A Reply to Professor Hamlyn, Journal of Philosophy of Education, Volume 9, Issue 1, 30 May 2006, Pages 40–48, https://d.

R K Elliott; Versions of Creativity, Journal of Philosophy of Education, Volume 5, Issue 2, 30 May 2006, Pages 139–152, https://doi.org/10.1111/j.1467-9752.1971.

R S Peters; Education and Justification, Journal of Philosophy of Education, Volume 11, Issue 1, 30 May 2006, Pages 28–38, https://doi.org/10.1111/j.1467-9752.1.

Jonathan Dancy’s Practical Reality defends a strikingly nonpsychologistic account of motivating reasons for action. When we explain what people do by citing their reasons, we are trying to isolate the considerations that were actually effective in moving them to act. But it is crucial, Dancy contends, that these considerations be understood in a way that preserves their connection to the normative contexts in which the concept of a reason also has a place. The considerations that move agents to act are (...) considerations that agents take to cast a favorable light on the actions they perform, and it is at least sometimes the case that peoples’ motivating reasons are also good reasons for action, considerations that really do recommend or speak in favor of the action that was undertaken. If we make the plausible further assumption that these normative reasons are typically not psychological states of the agents to whom they apply, it follows that motivating reasons equally cannot be understood in essentially psychological terms. The reasons for which people act are rarely if ever psychological states to which they are subject, but facts or states of the world of the sort that are capable of counting in favor of actions, and that in successful cases render sensible or reasonable the very actions that agents in fact perform. (shrink)

R T Allen; ‘Because I Say So!’ Some Limitations Upon the Rationalisation of Authority, Journal of Philosophy of Education, Volume 21, Issue 1, 30 May 2006, Page.

R T Allen; ‘Because I Say So!’ Some Limitations Upon the Rationalisation of Authority, Journal of Philosophy of Education, Volume 21, Issue 1, 30 May 2006, Page.

R Carlisle; The Concept of Physical Education, Journal of Philosophy of Education, Volume 3, Issue 1, 30 May 2006, Pages 5–22, https://doi.org/10.1111/j.1467-97.

R F Dearden; Happiness and Education, Journal of Philosophy of Education, Volume 2, Issue 1, 30 May 2006, Pages 17–29, https://doi.org/10.1111/j.1467-9752.1968.

R K Elliott; Aestheticism, Imagination and Schooling: a reply to Ruby Meager, Journal of Philosophy of Education, Volume 15, Issue 1, 30 May 2006, Pages 33–42.

R K Elliott; Aestheticism, Imagination and Schooling: a reply to Ruby Meager, Journal of Philosophy of Education, Volume 15, Issue 1, 30 May 2006, Pages 33–42.

R K Elliott; D. W. Hamlyn on Knowledge and the Beginnings of Understanding, Journal of Philosophy of Education, Volume 14, Issue 1, 30 May 2006, Pages 109–116.

R K Elliott; D. W. Hamlyn on Knowledge and the Beginnings of Understanding, Journal of Philosophy of Education, Volume 14, Issue 1, 30 May 2006, Pages 109–116.

R S Peters; A Reply to John Kleinig, Journal of Philosophy of Education, Volume 7, Issue 2, 30 May 2006, Pages 167–176, https://doi.org/10.1111/j.1467-9752.1973.

R M Hare; Value Education in a Pluralist Society, Journal of Philosophy of Education, Volume 10, Issue 1, 30 May 2006, Pages 7–23, https://doi.org/10.1111/j.146.

R J Royce; Public Schools: private privilege—a reply to Brenda Cohen, Journal of Philosophy of Education, Volume 16, Issue 1, 30 May 2006, Pages 105–113, https.