The paper introduces a first-order theory in the language of predicate tense logic which contains a single simple axiom. It is shewn that this theory enables times to be referred to and sentences involving ‘now’ and ‘then’ to be formalised. The paper then compares this way of increasing the expressive capacity of predicate tense logic with other mechanisms, and indicates how to generalise the results to other modal and tense systems.
Conducting research on adolescents raises a number of ethical issues not often confronted in research on younger children. In part, these differences are due to the fact that although assent is usually not an issue, given cognitive and social competencies, the life situations and behavior of youth make it more difficult to balance rights and privacy of the adolescents. In this article, the three ethical principles of beneficence, justice, and respect for persons are discussed in terms of their application to (...) the study of adolescents. Then, seven vignettes are presented to illustrate how these principles apply to real-life situations. How to balance the rights of adolescents and their parents is discussed, using adolescent girls and their parents for illustrative purposes. (shrink)
This long-awaited book replaces Hughes and Cresswell's two classic studies of modal logic: _An Introduction to Modal Logic_ and _A Companion to Modal Logic_. _A New Introduction to Modal Logic_ is an entirely new work, completely re-written by the authors. They have incorporated all the new developments that have taken place since 1968 in both modal propositional logic and modal predicate logic, without sacrificing tha clarity of exposition and approachability that were essential features of their earlier works. The book takes (...) readers from the most basic systems of modal propositional logic right up to systems of modal predicate with identity. It covers both technical developments such as completeness and incompleteness, and finite and infinite models, and their philosophical applications, especially in the area of modal predicate logic. (shrink)
The absence of a necessary connection in singular causation is a key step in the Humean argument against any form of necessity in causation. I argue that Hume's defence of this step is unsuccessful, and that the step could be skipped, accepting the possibility of necessary a posteriori truths. Still this does not suffice to guarantee a necessary connection in singular causation. Necessary a posteriori truths should be backed by necessary a priori truths. Thus, a main object of this paper (...) is to argue that an a priori philosophical concept of causality involves a necessary connection between its terms. (shrink)
Expressions in a language, whether words, phrases, or sentences, have meanings. So it seems reasonable to suppose that there are meanings that expressions have. Of course, it is fashionable in some philosophical circles to deny this.
Using as a springboard a three-way debate between theoretical physicist Lee Smolin, philosopher of science Nancy Cartwright and myself, I address in layman’s terms the issues of why we need a unified theory of the fundamental interactions and why, in my opinion, string and M-theory currently offer the best hope. The focus will be on responding more generally to the various criticisms. I also describe the diverse application of string/M-theory techniques to other branches of physics and mathematics which render the (...) whole enterprise worthwhile whether or not “a theory of everything” is forthcoming. (shrink)
In “Imposing Risks,” Judith Thomson gives a case in which, by turning on her stove, she accidentally causes her neighbor’s death. She claims that both the following are true: (1) she ought not to have caused her neighbor’s death; (2) it was permissible for her to turn her stove on. In this paper it is argued that it cannot be that both (1) and (2) are true, that (2) is true, and that therefore (1) is false. How this is so (...) is explained, and the implications of this position regarding the relation between rights and duties is explored. (shrink)
In this paper we examine the case of Tay, the Microsoft AI chatbot that was launched in March, 2016. After less than 24 hours, Microsoft shut down the experiment because the chatbot was generating tweets that were judged to be inappropriate since they included racist, sexist, and anti-Semitic language. We contend that the case of Tay illustrates a problem with the very nature of learning software that interacts directly with the public, and the developer's role and responsibility associated with it. (...) We make the case that when LS interacts directly with people or indirectly via social media, the developer has additional ethical responsibilities beyond those of standard software. There is an additional burden of care. (shrink)
The principal question of this paper is: Why are religious values special in refusal of lifesaving medical treatment? This question is approached through a critical examination of a common kind of refusal of treatment case, one involving a rational adult. The central value cited in defence of honouring such a patient's refusal is autonomy. Once autonomy is isolated from other justificatory factors, however, possible cases can be imagined which cast doubt on the great valuational weight assigned it by strong anti-paternalists. (...) This weight is sufficient, in their estimation, to justify honouring the patient's refusal. There is thus a tension between the strong anti-paternalist's commitment to the sufficiency of autonomy and our intuitions respecting such cases. Attempts can be made to relieve this tension, such as arguing that patients aren't really rational in the circumstances envisaged, or that other values, such as privacy or bodily integrity, if added to autonomy, are sufficient to justify an anti-paternalistic stance. All such attempts fail, however. But what does not fail is the addition of religious freedom, freedom respecting a patient's religious beliefs and values. Why religious freedom reduces the tension is then explained, and the specialness of religious beliefs and values examined. (shrink)
The book offers a proposal on how to define truth in all its complexity, without reductionism, showing at the same time which questions a theory of truth has to answer and which questions, although related to truth, do not belong within the scope of such a theory. Just like any other theory, a theory of truth has its structure and limits. The semantic core of the position is that truth-ascriptions are pro-forms, i.e. natural language propositional variables. The book also offers (...) an explanation of the syntactic behaviour of truth-terms, and the pragmatic roles of truth-acts. The theory of truth we present is a technical proposal, relatively uncontaminated by radical philosophical discussion. It makes indeed philosophical points, but it is intended to be a conceptual analysis, as neutral as possible, of the aspects that may serve as a point of departure for more philosophically-laden destinations. Like the Fregean account of quantifiers, which is prior to and, to a large extent, independent of the metaphysical debate about existence and its forms, or the Kaplanian view on demonstratives, that is neutral regarding the debate about individuals and the possibilities we have to actually “reach” them in a referring act, we intend our proposal about truth to be a sophisticated and explicative setting that helps to situate other debates about truth accurately, far from the distorted and sometimes strongly ideological discussions that have turned the topic into a paradigm of philosophical impasse. (shrink)
In a number of publications A.N. Prior considered the use of what he called ‘metric tense logic’. This is a tense logic in which the past and future operators P and F have an index representing a temporal distance, so that Pnα means that α was true n -much ago, and Fn α means that α will be true n -much hence. The paper investigates the use of metric predicate tense logic in formalising phenomena ormally treated by such devices as (...) multiple indexing or quantification over times. (shrink)
Various claims have been made, recently, that Darwin's argumentation in the Origin instantiates and so supports some general philosophical proposal about scientific theorizing, for example, the "semantic view". But these claims are grounded in various incorrect analyses of that argumentation. A summary is given here of an analysis defended at greater length in several papers by the present author. The historical and philosophical advantages of this analysis are explained briefly. Darwin's argument comprises three distinct evidential cases on behalf of natural (...) selection, cases, that is, for its existence, its adequacy and its responsibility. Theorizing, today, about evolution by natural selection involves a similar structure of evidential and explanatory concerns. (shrink)