Various formalisms for recasting quantum mechanics in the framework of classical mechanics on phase space are reviewed and compared. Recent results in stochastic quantum mechanics are shown to avoid the difficulties encountered by the earlier approach of Wigner, as well as to avoid the well-known incompatibilities of relativity and ordinary quantum theory. Specific mappings among the various formalisms are given.

Working in stochastic spin space and using POV measures as in the Davies and Lewis measurement scheme, we construct a formalism to describe the simultaneous measurement of incompatible spin components. The methods are illustrated with a new analysis of the Stern-Gerlach experiment, and with a discussion of spin dynamics in stochastic spin space. We also present a new short proof of a theorem on representations of spin-1/2 systems, find a joint spectral family for (noncommuting) spin components, and indicate the connection (...) of our result with the Riesz extension theorem. (shrink)

It is shown that stochastic observables defined by an instrument need not, and generally do not, commute.

The possibilities of a realistic interpretation of quantum mechanics are investigated by means of a statistical analysis of experiments performed on the simplest type of quantum systems carrying spin or helicity. To this end, fundamental experiments, some new, for measuring polarization are reviewed and (re)analyzed. Theunsharp reality of spin is essential in the interpretation of some of these experiments and represents a natural motivation for recent generalizations of quantum mechanics to a theory incorporating effect-valued measures as unsharp observables and generalized (...) systems of imprimitivity. (shrink)

This paper organizes the question of gun controls as violence policy under two quite different headings. The first issue to be discussed is the relationship between gun use and the death rate from violent crime. The second question is whether and how firearms control strategies might reduce the death rate from violence. When we review the evidence on the relationship between guns and violence, it seems clear that gun use, usually handgun use, increases the death rate from violence by a (...) factor of three to five. Nobody in mainstream social science or criminology argues against such weapon effects these days, although some are more skeptical of the magnitude estimated than others. Thus the problem is both genuine and important. (shrink)

This paper organizes the question of gun controls as violence policy under two quite different headings. The first issue to be discussed is the relationship between gun use and the death rate from violent crime. The second question is whether and how firearms control strategies might reduce the death rate from violence. When we review the evidence on the relationship between guns and violence, it seems clear that gun use, usually handgun use, increases the death rate from violence by a (...) factor of three to five. Nobody in mainstream social science or criminology argues against such weapon effects these days, although some are more skeptical of the magnitude estimated than others. Thus the problem is both genuine and important. (shrink)

What is 'praxis'? How do we study theology from its perspective? These are the main questions which this book seeks to answer.

Em artigo inédito, Franklin Leopoldo e Silva desenvolve os sentidos da memória na produção da identidade, destacando as relações significativas do presente com o passado e o futuro na construção da história. Desse ponto, o autor acentua o papel das instituições nesse processo – um processo de exercício de poder, no qual se tem, na verdade, a institucionalização do poder – e, dentre elas, em particular a instituição universitária.

Starting from the phase space representation of quantum mechanics we provide an Euclidean system of covariance for the photon. In particular, we consider systems with the Poincaré group as the symmetry group and use a standard procedure in order to build a phase space and a localization observable on the phase space. Then we focus on the massless representations of the Poincaré group that we use to build a space localization observable for the photon.

É bem conhecida a oposição estabelecida por Kant entre experiência possível e dialética, na medida em que esta última é caracterizada como a “lógica da ilusão”. Ao mesmo tempo, o modo de pensar metafísico, que ocorre dialeticamente, em sentido kantiano, é uma tendência inevitável da razão, expressa na exigência formal de completude das categorias. Como o pensar, enquanto exercício livre da razão, é em si mesmo mais amplo do que a atividade de conhecer, própria do entendimento, o pensar contém o (...) conhecimento, embora este se qualifique pelas regras e pelos limites determinantes da objetividade. A pergunta que tentaremos formular é se essa relação continente-conteúdo não poderia configurar também uma dependência da experiência em relação ao raciocínio dialético, que estaria de algum modo indicada na função reguladora das idéias da razão. Nesse caso, a oposição formal entre conhecer e pensar seria inseparável da inclusão estrutural (dependência) da experiência no âmbito da razão. Na raiz do problema estaria talvez a tensão (dialética) entre a aspiração subjetiva de totalidade e as exigências objetivas de limitação e segmentação da experiência e a forma da experiência teria de ser finalmente concebida a partir de um fundo de inteligibilidade problemática. Dialectics and experienceThe separation of possible experience as objective knowledge and dialetics as a non-objective or non-theoretical knowledge is one of the most important aspects of kantian critical philosophy. But Kant also says that the activity of reason, as a pure thinking, has more amplitude than understanding knowledge. So we could say that theoric knowledge would depend on rational ( and non-theoretical) knowledge, as something contained in it. If we accept that, the consequence would be a relation of dependence between the form of objective knowledge and the background of a problematic – even doubtful – inteligible knowledge. (shrink)

Hospice is the premiere end of life program in the United States, but its requirement that patients forgo disease-directed therapies and that they have a prognosis of 6 months or less means that it serves less than half of dying patients and often for very short periods of time. Palliative care offers careful attention to pain and symptom management, added support for patients and families, and assistance with difficult medical decision making alongside any and all desired medical treatments, but it (...) does not include a comprehensive system of care as is provided by hospice. The practice of palliative care and hospice is filled with sometimes overt (requests for hastened death in an environment where such acts are legally prohibited) and other times covert (the delay in palliative care referral because the health care team believes it will undermine disease directed treatment) ethical issues. The contributors to this volume use a series of case presentations within each chapter to illustrate some of the palliative care and hospice challenges with significant ethical dimensions across the three overarching domains: 1) care delivery systems; 2) addressing the many dimensions of suffering; and 3) difficult decisions near the end of life. The contributors are among the most experienced palliative care, hospice and ethics scholars in North America and Western Europe. Each has been given relatively free reign to address what they feel are the most pressing ethical challenges within their domain, so a wide range of positions and vantage points are represented. As a result, the volume provides a very diverse ethical exploration of this relatively young field that can deepen, stretch, and at times confront any simple notion of the challenges facing patients, their families, professional caregivers, and policy makers. (shrink)

The internal paradoxes in the quantum measurement scheme related to violation of conservation laws, changes in entropy, absence of a dynamic description of collapse, Wigner's friend, as well as the paradox of violation of causality in the EPR experiment are shown to be partially circumvented in the measurement scheme of stochastic quantum mechanics.

The language of manuals may be used to discuss inference in measurement in a general experimental context. Specializing to the context of the frame manual for Hilbert space, this inference leads to state dominance of the inferred state from partial measurements; this in turn, by Sakai's theorem, determines observables which are described by positive operator-valued measures. Symmetries are then introduced, showing that systems of covariance, rather than systems of imprimitivity, are natural objects to study in quantum mechanics. Experiments measuring different (...) polarization components simultaneously are reexamined in this language. Finally, implications of the Naimark extension theorem for the manual approach are investigated. (shrink)

With breathtalung speed, traditional criminal prohibitions against assisted suicide have been declared unconstitutional in twelve states, including California and New York. This poses great promise and great peril. The promise is that competent terminally ill patients, as a compassionate measure of last resort, will have the option of putting an end to their suffering by physician-assisted suicide. More sigmficant, legally permitting this controversial option may be a catalyst for doctors, health care institutions, and society to improve the care of the (...) dying. PAS should be limited only to those relatively few competent patients who continue to suffer intolerably despite unrestrained efforts to palliate and who face a continued existence that they regard as worse than death. When dying patients know they will not be abandoned to miserable and pointless suffering if palliative care fails, they will be fortified to cope better with the process of dying.The immediate peril is that PAS will become a quick fix, available on demand to any patient diagnosed as terminally ill, thus bypassing palliative care and producing premature deaths. (shrink)

O presente texto procura acompanhar alguns aspectos da reconstrução sartreana das relações entre indivíduo e história, tentando mostrar que a fenomenologia e o materialismo dialético comparecem nessa proposta de conhecimento e que é a convergência das duas perspectivas que permite, contemplando adequadamente a universalidade e a singularidade, descrever e compreender dialeticamente o modo histórico de produção da identidade individual.

Esse texto pretende indicar um modo de aproximação da noção d e subjetividade tal como ela aparece especificamente na Critica do Juízo : a especificidade do juízo refle xionant e como ato subjetivo. A fu nção de ajuizar, no seu estrato pre-cate gorial, pode nos fornecer a i ndicação de uma possibilidade interpretativa fundada na conjunção entre mundo natural e mundo prático como o universo da nova fo rm a de juizo.

A partir da concepção de um racionalismo integral, em que vigora o ideal da plena demonstrabilidade segundo o paradigma identitário da verdade, configura-se em Leibniz a questão da universalidade, que seria enunciada com mais pertinência como a do determinismo universal. São dois aspectos de uma mesma questão: em primeiro lugar, a universalidade no sentido arquitetônico, correspondente à totalidade; em segundo lugar, a determinação absoluta do indivíduo singular. Tanto num caso quanto no outro, a plena determinação é inalcançável para a mente (...) humana. Mas as operações simbólicas de determinação, permitem, de alguma maneira, contornar a impossibilidade de uma visão simultânea e articulada de todos os elementos de um composto e, assim, nos encaminham na direção de uma universalidade determinante. Os fundamentos, os procedimentos e os riscos aí envolvidos constituem o tema desse texto. (shrink)

A questão que se tenta construir neste texto é a da convergência entre filosofia, história da filosofia e formação. Tal pergunta se desdobra primeiramente na elucidação das relações entre história e historicidade da filosofia, que remonta à constatação óbvia, mas nem sempre lembrada, de que o fundamento da história da filosofia é o caráter histórico da própria filosofia. A idéia de formação está presente em toda filosofia, já que, antes de ser sistema ou concepção cristalizada da realidade, cada filosofia é (...) sempre um exercício de síntese das possibilidades e das circunstâncias da vida humana, inclusive sob o aspecto do trabalho da reflexão. Nesse sentido, o texto remete a algumas idéias de Bergson acerca de formação e processo, e à noção sartriana de práxis como formação e superação contínua dos momentos estruturais do curso da história. Assim compreendida, a relação entre história da filosofia e filosofia contém inevitavelmente o compromisso com a atualidade, isto é, com a formação atual do pensamento. (shrink)

Este texto procura explicitar alguns aspectos da interpretação bergsoniana de Aristóteles, sobretudo aqueles que fazem de Aristóteles um eminente representante do que Bergson denomina Filosofia das formas. A leitura bergsoniana procura mostrar que não há diferença significativa entre Aristóteles e Platão, na medida em que ambos comprometem-se com a fundação do conhecimento a partir da ontologia de Parmênides. Desta maneira, o quadro categorial aristotélico e o princípio ontológico da Forma da Formas, ou Forma Pura, tentam solucionar a aporia parmenídica remetendo (...) a imobilidade ao estranho lógico do conhecimento, ou a objetividade ao conhecimento das existências em seu caráter lógico. (shrink)

This paper discuss the relations between the transcendental analysis of Kantian's Ideas of Reason and the traditional Metaphysical heritage. We try to understand the first Part of the Apendix Transcendental Dialectics under the light of critical remaking of the metaphysical themes, with special accent on the scholastic notion of "Transcendental atribute of Being".O presente artigo discute as relações entre a perspectiva transcendental inscrita na análise Kantiana das Idéias da Razão e a herança metafísica tradicional. Para tanto ensaia-se uma leitura da (...) 1ª parte do Apêndice da Dialética Transcendental à luz da reelaboração critica do temário metafísico, com especial ênfase na noção escolástica de atributo transcendental do Ser. (shrink)

Este texto pretende indicar alguns aspectos da trajetória da noção de beatitude, de Agostinho a Descartes. Através da transformação semântico-conceitual da expressão homo capax Dei, podemos observar que, de Agostinho a Tomás de Aquino e deste a Suarez e a Descartes, a beatitude vai progressivamente deixando de ser entendida como capacidade de “conter” Deus e torna-se cada vez mais a capacidade racional - “natural” - de “pensar” Deus.

Symmetries are introduced into the convexity approach to physics. This allows one to make connections between classical and quantum theories by exploiting the properties of quantum mechanics on phase space. The measurement problem is discussed and many of the known no-go theorems are shown not to apply. Finally, hidden variable theories exhibiting these physical symmetries are shown to have a certain required group structure, if they exist at all.