Multiple -conclusion logic extends formal logic by allowing arguments to have a set of conclusions instead of a single one, the truth lying somewhere among the conclusions if all the premises are true. The extension opens up interesting possibilities based on the symmetry between premises and conclusions, and can also be used to throw fresh light on the conventional logic and its limitations. This is a sustained study of the subject and is certain to stimulate further research. Part I reworks (...) the fundamental ideas of logic to take account of multiple conclusions, and investigates the connections between multiple - and single - conclusion calculi. Part II draws on graph theory to discuss the form and validity of arguments independently of particular logical systems. Part III contrasts the multiple - and the single - conclusion treatment of one and the same subject, using many-valued logic as the example; and Part IV shows how the methods of 'natural deduction' can be matched by direct proofs using multiple conclusions. (shrink)

The effects in a quantum-mechanical system form a partial algebra and a partially ordered set which is the prototypical example of the effect algebras discussed in this paper. The relationships among effect algebras and such structures as orthoalgebras and orthomodular posets are investigated, as are morphisms and group- valued measures (or charges) on effect algebras. It is proved that there is a universal group for every effect algebra, as well as a universal vector space over an arbitrary field.

This new translation of _De Caelo_ fits seamlessly with other volumes in the New Hackett Aristotle series, enabling Anglophone readers to study Aristotle’s work in a way previously not possible. The Introduction describes the book that lies ahead, explaining what it is about, what it is trying to do, how it goes about doing it, and what sort of audience it presupposes. Sequentially numbered endnotes provide the information most needed at each juncture, while a detailed Index indicates the places where (...) focused discussion of key notions occurs. (shrink)

Background: The traditional approach to resolving ethics concerns may not address underlying organisational issues involved in the evolution of these concerns. This represents a missed opportunity to improve quality of care “upstream”. The purpose of this study was to understand better which organisational issues may contribute to ethics concerns. Methods: Directed content analysis was used to review ethics consultation notes from an academic children’s hospital from 1996 to 2006 (N = 71). The analysis utilised 18 categories of organisational issues derived (...) and modified from published quality improvement protocols. Results: Organisational issues were identified in 68 of the 71 (96%) ethics consult notes across a range of patient settings and reasons for consultation. Thirteen of the 18 categories of organisational issues were identified and there was a median of two organisational issues per consult note. The most frequently identified organisational issues were informal organisational culture (eg, collective practices and approaches to situations with ethical dimensions that are not guided by policy), policies and procedures (eg, staff knows policy and/or procedural guidelines for an ethical concern but do not follow it) and communication (eg, communication about critical information, orders, or hand-offs repeatedly does not occur among services). Conclusions: Organisational issues contribute to ethical concerns that result in clinical ethics consults. Identifying and addressing organisational issues such as informal culture and communication may help decrease the recurrence of future similar ethics concerns. (shrink)

Recent studies using functional magnetic resonance imaging of patients in a vegetative state have raised the possibility that such patients retain some degree of consciousness. In this paper, the ethical implications of such findings are outlined, in particular in relation to decisions about withdrawing life-sustaining treatment. It is sometimes assumed that if there is evidence of consciousness, treatment should not be withdrawn. But, paradoxically, the discovery of consciousness in very severely brain-damaged patients may provide more reason to let them die. (...) Although functional neuroimaging is likely to play an increasing role in the assessment of patients in a vegetative state, caution is needed in the interpretation of neuroimaging findings. (shrink)

We bring out the fact that the essential new quality implied by the quantum theory is nonlocality; i.e., that a system cannot be analyzed into parts whose basic properties do not depend on the state of the whole system. This is done in terms of the causal interpretation of the quantum theory, proposed by one of us (D.B.) in 2952, involving the introduction of the “quantum potential.” We show that this approach implies a new universal type of description, in which (...) the standard or canonical form is always supersystem-system-subsystem; and this leads to the radically new notion of unbroken wholeness of the entire universe. Finally, we discuss some of the implications of extending these notions to the relativity domain, and in so doing, we indicate a novel concept of time, in terms of which relativity and quantum theory may eventually be brought together. (shrink)

The ordinary concept of death is analysed and compared with revisionary medical definitions, especially those based on irreversible loss of brain function. Prior critics of revisionary definitions have focused on the locus, the brain; I am concerned with the irreversibility condition. I argue that 1) the irreversibility condition is ambiguous, 2) it has unacceptable epistemic and other consequences on any plausible construal, and 3) irreversibility is not part of the ordinary concept of death. I conclude that recent medical definitions seek (...) illegitimately to obtain the certainty of a weak construal of 'irreversible' along with the freedom from moral obligation of the strong construal. (shrink)

The letter sent by the Royal Society to the London optician, John Marshall, in 1694, commending his new method of grinding, has been reprinted, and referred to, in recent years. However, there has been no comprehensive analysis of the method itself, the letter and the circumstances in which it was written, nor the consequences for trade practices. The significance of the approval by the Royal Society of this innovation and the use of that approbation by John Marshall and other practitioners (...) are examined. Gaps in existing accounts of Marshall's method are partly remedied by supplementing surviving written materials with accounts of contemporary, and present-day, trade practices based on his method. The reasons why Marshall and his contemporaries failed to record his method and specify his improvements are discussed. The reactions of the Spectacle Makers' Company and its more prominent members, both to the innovation itself and to the Royal Society's letter, are analysed. The impact of the new technique on contemporary and later opticians is described. (shrink)