In this book some options concerning the greenhouse effect are assessed from a welfarist point of view: business as usual, stabilization of greenhouse gas emissions and reduction by 25% and by 60%. Up to today only economic analyses of such options are available, which monetize welfare losses. Because this is found to be wanting from a moral point of view, the present study welfarizes (among others) monetary losses on the basis of a hedonistic utilitarianism and other, justice incorporating, welfare ethics. (...) For these welfarist evaluations information about the social consequences of the four options are collected from the literature and eventually corrected; then the consequences for individual well-being are assessed based on psychological research about well-being dependent on the social situation of the individual; finally the aggregation formulas of the respective welfare ethics are applied to these data. Assessments by other types of ethics, e.g. Kantian ethic, are included. The strongest abatement option is found to be optimum with great unanimity. - In addition a cost-welfare analysis of greenhouse gas abatement is undertaken revealing efficient cost-welfare ratios for these measures and the most efficient ratio for the strongest option. - A final, more theoretical part discusses the moral obligations following from such evaluations. The notion of 'moral obligation' is explained in a way that, apart from moral goodness of the required act, reinforcement by formal or informal sanctions is another necessary condition for moral obligations. This leads to a conception of a historical morality according to which the demands of morality rise in the long run. Applying this conception to the greenhouse effect implies that presently we have the moral duty to raise the standards of greenhouse gas abatement as much as is politically feasible. (shrink)

The research discussed in this paper concerns an investigation of logical dialogue games as a vehicle for enhanced human-computer communication. The need for a dialogue capability in computer systems is argued, and a prima facie case made for dialogue games, in particular Mackenzie's "DC", as a suitable dialogue model. Empirical work concerning DC is outlined, and strategies for adoption by the computer are presented. A user interface, software architecture and conceptualised example are discussed. The hope is that the paper will (...) help bring together two groups of workers-philosophers of dialogue and designers of computer systems-to the mutual benefit of each. (shrink)

Dialogical logic is a game-theoretical approach to logic. Logic is studied with the help of certain games, which can be thought of as idealized argumentations. Two players, the Proponent, who puts forward the initial thesis and tries to defend it, and the Opponent, who tries to attack the Proponent’s thesis, alternately utter argumentative moves according to certain rules. For a long time the dialogical approach had been worked out only for classical and intuitionistic logic. The seven papers of this dissertation (...) show that this narrowness was uncalled for. The initial paper presents an overview and serves as an introduction to the other papers. Those papers are related by one central theme. As each of them presents dialogical formulations of a different non-classical logic, they show that dialogical logic constitutes a powerful and flexible general framework for the development and study of various logical formalisms and combinations thereof. As such it is especially attractive to logical pluralists that reject the idea of “the single correct logic”. The collection contains treatments of free logic, modal logic, relevance logic, connexive logic, linear logic, and multi-valued logic. (shrink)

The purpose of this paper is twofold: to give a good account of the argument from ignorance, with a presumptive argumentation scheme, and to raise issues on the work of Walton, the nature of abduction and the concept of epistemic closure. First, I offer a brief disambiguation of how the terms 'argument from ignorance' and 'argumentum ad ignorantiam' are used. Second, I show how attempts to embellish this form of reasoning by Douglas Walton and A.J. Kreider have been unnecessary and (...) unhelpful. Lastly, I offer a full and effective account of the argument from ignorance and discuss the lessons of the analysis.Le but de cet article est double: donner un bon compte rendu de l'argument par l'ignorance, avec un schème d'argumentation présomptif, et soulever des questions sur certains aspects de l’œuvre de Walton, la nature des raisonnements abductifs et le concept de fermeture épistémique. Premièrement, j'offre une brève désambiguïsation de la façon dont les termes «argument par l'ignorance» et «argumentum ad ignorantiam» sont utilisés. Deuxièmement, je montre comment les tentatives de Douglas Walton et de A.J. Kreider d'embellir cette forme de raisonnement ont été ni nécessaires et ni utiles. Enfin, j'offre un compte-rendu complet et utile de l'argument par l'ignorance et je discute des leçons de l'analyse. (shrink)

Wellman identified three types of conductive arguments, the third of which contains both pro and counter-considerations in the same piece of reasoning. This paper provides a pragma-dialectical analysis of this type of argumentation, with special focus on argumentation reconstruction. It argues that the account of pro/con argumentation in the framework of argument-as-product has problems solvable by a pragma-dialectical approach. The paper asserts that pro/con argumentation should be analyzed as a dialectical strategy of a protagonist, where acknowledgement of counter-considerations shows that (...) the antagonist’s reasons have been taken into consideration, although the pro-considerations override them. Thus, the pro-considerations of pro/con argumentation should be interpreted as the protagonist’s overriding defeaters of the antagonist’s counter-arguments, the protagonist incorporating the latter as counter-considerations. The paper further argues that the pragma-dialectical framework needs an additional conceptual tool to properly reconstruct complex forms of pro/con argumentation. Finally, the pragma-dialectical approach to reconstruct pro/con argumentation has several advantages, especially to a more logical-structural approach to complex pro/con argumentation. (shrink)

This article consists of three parts, two introductory, in which the limits and the methods of analysis of dialogues are expounded, and the major part, in which the main features of a philosophical theory of disputation are outlined.It was an essential aim of the philosophical analysis of argumentative dialogues to develop tools of substantiation for cases in which logic doesn't help any more. In the first part of this paper I show that such tools can and will be developed only (...) by analyzing argumentations (“argumentation” in the sense of a monologue in which arguments for a thesis are brought forward), and that the analysis of argumentative dialogues doesn't contribute anything to the development of such tools.The systematically first task of the philosophical analysis of dialogues consists in understanding the general practical aims of philosophically interesting types of dialogue. Only subsequently the rules of the dialogue can be reconstructed as good means for reaching these aims. Dialogical games constructed without referring to such a purpose are externally senseless and useless.The third part is an outline of a philosophical theory of disputation (“disputation” here will mean: (learned) dialogue in which the participants cooperatively though perhaps controversially attempt to find out by means of arguments and mutual criticism whether a thesis is true or false). Disputations contain argumentations, and many functions of a disputation can also be fulfilled by argumentations alone. Certifying the truth of convictions is the specific aim of disputation. This is accomplished by eliminating errors of substantiation and foundation as effectively as possible, in revising false convictions and their foundations, thereby making the remaining convictions more certain. Based on this analysis of the aim of disputation, the basic rules of disputations will be critically reconstructed: possible moves, rules of sequence, and the internal aim and ends of disputations. (shrink)

Needed for such dialogue games as dialectic are appropriate standards of fairness and rationality. The rules of procedure of dialectic must describe a game playable by actual human participants. The present paper centers on certain idealizations of the dialectician that are not allowable.

Design deliberation refers to the process of thoughtfully weighing options, before making a design decision. This process is strongly related to argumentation, not only because of the well-known relation between argumentation and deliberation, but also due to characteristics of the design process. However, no structural model of team design deliberation exists to guide designers’ practice. This paper checks the hypothesis of inter-dependence between argument structures and group decision-making struc-ture as expressed through prescribed deliberation stages.

The purpose of this paper is to discuss some ways in which dialectical models can be put to computational use. In particular, we consider means of facilitating human-computer debate, means of catering for a wider range of dialogue types than purely debate and means of providing dialectical support for group dialogues. We also suggest how the computational use of dialectical theories may help to illuminate research issues in the field of dialectic itself.