Sven Ove Hansson

​This book describes argumentative tools and strategies that can be used to guide policy decisions under conditions of great uncertainty. Contributing authors explore methods from philosophical analysis and in particular argumentation analysis, showing how it can be used to systematize discussions about policy issues involving great uncertainty. The first part of the work explores how to deal in a systematic way with decision-making when there may be plural perspectives on the decision problem, along with unknown consequences of what we do. Readers will see how argumentation tools can be used for prioritizing among uncertain dangers, for determining how decisions should be framed, for choosing a suitable time frame for a decision, and for systematically choosing among different decision options. Case studies are presented in the second part of the book, showing argumentation in practice in the areas of climate geoengineering, water governance, synthetic biology, nuclear waste, and financial markets. In one example, argumentation analysis is applied to proposals to solve the climate problem with various technological manipulations of the natural climate system, such as massive dispersion of reflective aerosols into the stratosphere. Even after a thorough investigation of such a proposal, doubt remains as to whether all the potential risks have been identified. In such discussions, conventional risk analysis does not have much to contribute since it presupposes that the risks have been identified, whereas the argumentative approach to uncertainty management can be used to systematize discussions.

This book provides a critical examination of how the choice of what to believe is represented in the standard model of belief change. In particular the use of possible worlds and infinite remainders as objects of choice is critically examined. Descriptors are introduced as a versatile tool for expressing the success conditions of belief change, addressing both local and global descriptor revision. The book presents dynamic descriptors such as Ramsey descriptors that convey how an agent’s beliefs tend to be changed in response to different inputs. It also explores sentential revision and demonstrates how local and global operations of revision by a sentence can be derived as a special case of descriptor revision. Lastly, the book examines revocation, a generalization of contraction in which a specified sentence is removed in a process that may possibly also involve the addition of some new information to the belief set.

This volume is the first extensive study of the historical and philosophical connections between technology and mathematics. Coverage includes the use of mathematics in ancient as well as modern technology, devices and machines for computation, cryptology, mathematics in technological education, the epistemology of computer-mediated proofs, and the relationship between technological and mathematical computability. The book also examines the work of such historical figures as Gottfried Wilhelm Leibniz, Charles Babbage, Ada Lovelace, and Alan Turing.

Clear-cut cases of decision-making under risk (known probabilities) are unusual in real life. The gambler’s decisions at the roulette table are as close as we can get to this type of decision-making. In contrast, decision-making under uncertainty (unknown probabilities) can be exemplified by a decision whether to enter a jungle that may contain unknown dangers. Life is usually more like an expedition into an unknown jungle than a visit to the casino. Nevertheless, it is common in decision-supporting disciplines to proceed as if reasonably reliable probability estimates were available for all possible outcomes, i.e. as if the prevailing epistemic conditions were analogous to those of gambling at the roulette table. This mistake can be called the tuxedo fallacy. It is argued that traditional engineering practices such as safety factors and multiple safety barriers avoid this fallacy and that they therefore manage uncertainty better than probabilistic risk analysis (PRA). PRA is a useful tool, but it must be supplemented with other methods in order not to limit the analysis to dangers that can be assigned meaningful probability estimates.

It is almost universally acknowledged that risks have to be weighed against benefits, but there are different ways to perform the weighing. In conventional risk analysis, collectivist risk-weighing is the standard. This means that an option is accepted if the sum of all individual benefits outweighs the sum of all individual risks. In practices originating in clinical medicine, such as ethical appraisals of clinical trials, individualist risk-weighing is the standard. This implies a much stricter criterion for risk acceptance, namely that the risk to which each individual is exposed should be outweighed by benefits for that same individual. The different choices of risk-weighing methods in different policy areas seem to have emerged from traditional thought patterns and social relations, rather than from explicit deliberations on possible justifications for the alternative ways to weigh risks against benefits. It is not obvious how the prevalent differences in risk-weighing practices can be reconstructed in terms of consistent underlying principles of preventive health or social priority-setting.

Workplace inspections are undertaken because they are believed to lead to better conditions In the workplace. It is therefore essential to know if inspections have the desired effects on working conditions. We introduce a theoretical framework for the evaluation of workplace inspections with respect to their effects on working conditions. Criteria of efficiency and priority-setting are discussed. Some empirical results concerning priority-setting in Swedish inspection agencies are presented. Further, we argue that in order to obtain reliable information about the effects of different inspection methods, it is necessary to perform controlled comparative studies in which different methods are used in different workplaces. Given the facility with which such studies can be performed, it is surprising how few such studies have been made. We conclude by surveying some empirical studies that concern the issue of efficient inspections.

The typical function of goals is to regulate action in a way that furthers goal achievement. Goals are typically set on the assumption that they will help bring the agent closer to the desired state of affairs. However, sometimes endorsement of a goal, or the processes by which the goal is set, can obstruct its achievement. When this happens, the goal is self-defeating. Self-defeating goals are common in both private and social decision-making but have not received much attention by decision theorists. In this paper, we investigate different variants of three major types of self-defeating mechanisms: The goal can be an obstacle to its own fulfilment, goal-setting activities can impede goal achievement, and disclosure of the goal can interfere with its attainment. Different strategies against self-defeasance are tentatively explored, and their efficiency against different types of self-defeasance is investigated.

As part of the conference commemorating Theoria's 75th anniversary, a round table discussion on philosophy publishing was held in Bergendal, Sollentuna, Sweden, on 1 October 2010. Bengt Hansson was the chair, and the other participants were eight editors-in-chief of philosophy journals: Hans van Ditmarsch (Journal of Philosophical Logic), Pascal Engel (Dialectica), Sven Ove Hansson (Theoria), Vincent Hendricks (Synthese), Søren Holm (Journal of Medical Ethics), Pauline Jacobson (Linguistics and Philosophy), Anthonie Meijers (Philosophical Explorations), Henry S. Richardson (Ethics) and Hans Rott (Erkenntnis)

As part of the conference commemorating Theoria's 75th anniversary, a round table discussion on philosophy publishing was held in Bergendal, Sollentuna, Sweden, on 1 October 2010. Bengt Hansson was the chair, and the other participants were eight editors‐in‐chief of philosophy journals: Hans van Ditmarsch (Journal of Philosophical Logic), Pascal Engel (Dialectica), Sven Ove Hansson (Theoria), Vincent Hendricks (Synthese), Søren Holm (Journal of Medical Ethics), Pauline Jacobson (Linguistics and Philosophy), Anthonie Meijers (Philosophical Explorations), Henry S. Richardson (Ethics) and Hans Rott (Erkenntnis).

The AGM theory of belief contraction is extended tomultiple contraction, i.e. to contraction by a set of sentences rather than by a single sentence. There are two major variants: Inpackage contraction all the sentences must be removed from the belief set, whereas inchoice contraction it is sufficient that at least one of them is removed. Constructions of both types of multiple contraction are offered and axiomatically characterized. Neither package nor choice contraction can in general be reduced to contractions by single sentences; in the finite case choice contraction allows for reduction.

Healthcare depends increasingly on advanced medical technology. In addition, other forms of technology contribute to determine how our lives are influenced by disease and disability. The extent to which persons with impaired bodily functions are forced to live their lives differently than other people depends to a large part on a variety of technologies, from wheelchairs to computer interfaces, from hearing aids to garage doors. This wide-ranging influence of technology has important ethical aspects, but has seldom been discussed in bioethics, the ethics of technology, or other branches of applied ethics