First published in 2000. Routledge is an imprint of Taylor & Francis, an informa company.

Global properties of canonical derivability predicates in Peano Arithmetic) are studied here by means of a suitable propositional modal logic GL. A whole book [1] has appeared on GL and we refer to it for more information and a bibliography on GL. Here we propose a sequent calculus for GL and, by exhibiting a good proof procedure, prove that such calculus admits the elimination of cuts. Most of standard results on GL are then easy consequences: completeness, decidability, finite model property, (...) interpolation and the fixed point theorem. (shrink)

One of the areas of concern raised by cross-border reproductive travel regards the treatment of women who are solicited to provide their ova or surrogacy services to foreign consumers. This is particularly troublesome in the context of developing countries where endemic poverty and low standards for both medical care and informed consent may place these women at risk of exploitation and harm. We explore two contrasting proposals for policy development regarding the industry, both of which seek to promote ethical outcomes (...) and social justice: While one proposal advocates efforts to minimize cross-border demand for female reproductive resources through the pursuit of national self-sufficiency, the other defends cross-border trade as a means for meeting the needs of vulnerable groups. Despite the conflicting objectives of the proposed strategies, the paper identifies common values and points of agreement between the two, including the importance of regulations to safeguard those providing ova or surrogacy services. (shrink)

The principle of “equivalence of care” in prison medicine is a principle by which prison health services are obliged to provide prisoners with care of a quality equivalent to that provided for the general public in the same country. It is cited in numerous national and international directives and recommendations.The principle of equivalence is extremely relevant from the point of view of normative ethics but requires adaptation from the point of view of applied ethics. From a clinical point of view, (...) the principle of equivalence is often insufficient to take account of the adaptations necessary for the organization of care in a correctional setting. The principle of equivalence is cost-effective in general, but has to be overstepped to ensure the humane management of certain special cases. (shrink)

The current Ebola epidemic has presented challenges both medical and ethical. Although we have known epidemics of untreatable diseases in the past, this particular one may be unique in the intensity and rapidity of its spread, as well as ethical challenges that it has created, exacerbated by its geographic location. We will look at the infectious agent and the epidemic it is causing, in order to understand the ethical problems that have arisen.

Relatively congruence regular quasivarieties and quasivarieties of logic have noticeable similarities. The paper provides a unifying framework for them which extends the Blok-Pigozzi theory of elementarily algebraizable (and protoalgebraic) deductive systems. In this extension there are two parameters: a set of terms and a variable. When the former is empty or consists of theorems, the Blok-Pigozzi theory is recovered, and the variable is redundant. On the other hand, a class of membership logics is obtained when the variable is the only (...) element of the set of terms. For these systems the appropriate variant of equivalent algebraic semantics encompasses the relatively congruence regular quasivarieties. (shrink)

Ecological theory is built upon assumptions about the fundamental nature of organism-environment interactions. We argue that two mutually exclusive sets of such assumptions are available and that they have given rise to alternative approaches to studying ecology. The fundamentally different premises of these approaches render them irreconcilable with one another. In this paper, we present the first logical formalisation of these two paradigms.The more widely-accepted approach - which we label the demographic paradigm - includes both population ecology and community ecology (...) (synecology). Demographic ecology assumes that the environment is relatively stable and that biotic processes, governed predominantly by resource availability, are the most important of ecological and evolutionary influences. Moreover, ecological processes are assumed to translate into directional selection pressures that drive significant evolutionary change on a local scale through the process of optimisation. (shrink)

Social inequalities in health in the UK persist despite attempts to reduce them. We argue that work and pensions constitutes an area of intervention where there is potential to make change happen. We propose that workers who are exposed to significant health risks through their occupation should be allowed to draw their state pension earlier, based on a minimum number of years in the workforce. We model this proposal on similar policies in other European countries. In our modification, the pension (...) age and the retirement age would be separated, such that workers can receive a state pension whether or not they choose to continue working. This arrangement may encourage workers either to reduce their working hours or to change to less demanding or harmful work. The health of these workers would thereby benefit from reduced exposure to a harmful work environment, reduced stress and more opportunities for rest and relaxation. However, it has also been suggested that retirement is bad for mental health. In response, our proposal enables workers to phase in full retirement over a period of part-time work, and we believe that this would counter any potential negative effects on health caused by retirement. (shrink)

This book attempts, through a series of interpretive discussions, to confront a number of well-known perplexities in their structural form of disjunctive moments, of interpretive contexts of 'this is' and 'this is not.'.

Zermelo once wrote that he had anticipated Russell's contradiction of the set of all sets that are not members of themselves. Is this sufficient for having anticipated Russell's Paradox — the paradox that revealed the untenability of the logical notion of a set as an extension? This paper argues that it is not sufficient and offers criteria that are necessary and sufficient for having discovered Russell's Paradox. It is shown that there is ample evidence that Russell satisfied the criteria and (...) that Zermelo did not. (shrink)

John Rawls’ use of a contractarian strategy for justifying basic principles of justice has raised the hope that a similar strategy might work for a theory of right and moral principles generally. I want to show that this hope cannot be fulfilled.In what follows I interpret contractarianism in a Rawlsian way on the grounds that his is the most plausible version of the doctrine we are likely to get. I am not however concerned with the details of Rawls’ argument for (...) justice but instead with an idea that appears to underlie the contractarian strategy. In order to avoid the complications of Rawlsian exegesis, I choose to discuss the doctrine as it might be used to justify a moral principle of mutual assistance and not as Rawls in fact uses it to justify principles of justice. (shrink)