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)

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.

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)

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.

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.

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)

I aim to show that the practice of reading excellent literature is an excellent form of moral education. I offer a two-stage defense. First, I call attention to central features of the human self (especially the emotions) involved in moral growth. I argue that the central components of emotions are construals (or ways of seeing) and loves. Second, I show that literature has distinctive resources both to train our construals by affording us practice in seeing the world in new ways (...) and to cultivate our loves by affording us practice in imitating the loves of others. (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.

We know from experience that a stable feature of the human predicament is internal alienation: our various psychic states are often in conflict with one another. We are divided selves. In this paper, I delineate the nature and argue for the importance of a spiritual discipline of reading literature as a way of addressing this division. My argument comes in two stages. First, I offer a diagnosis of why we fail to be wholehearted that develops Aristotle’s idea that a fundamental (...) source of internal division within the soul is between what we know and how we see or construe our present situation. Second, I show how a spiritual discipline of reading literature is the right prescription for retraining our habits of construal so as to bring them into harmony with our knowledge. I conclude with a few remarks about how to put this discipline into practice. (shrink)