In the first part of this paper, I clear the ground from frequent misconceptions of the relationship between fact and value by examining some uses of the adjective “natural” in ethical controversies. Such uses bear evidence to our “natural” tendency to regard nature as the source of ethical norms. I then try to account for the origins of this tendency by offering three related explanations, the most important of which is evolutionistic: if any behaviour that favours our equilibrium with the (...) environment is potentially adaptive, nothing can be more effective for this goal than developing an attitude toward the natural world that considers it as a dispenser of sacred norms that must be invariably respected. By referring to the Aristotelian notion of human flourishing illustrated in the first part of the paper, in the second I discuss as a case study some ethical problems raised by mini-chips implantable in our bodies. I conclude by defending their potential beneficial effects of such new technological instruments. (shrink)

SUGGESTED COURSES Introductory level A (Requires very little background in logic .): 4: -9 - - -7 -2 Introductory level B: -9,:+-+ -,2:+,2: -,3:20+-22+ -7 -2 ...

In the middle of the 1980s, logical tools were discovered that make it possible to model changes in belief and knowledge in entirely new ways. These logical tools turned out to be applicable both to human beliefs and to the contents of databases. This is the first textbook in this new area. It contains both discursive chapters with a minimum of formalism and formal chapters in which proofs and proof methods are presented. By using different selections from the formal section (...) the book can be used on all levels of University education. (shrink)

The relatively new discipline of risk analysis promises to provide objective guidance in some of the most controversial issues in modern high‐technology societies. Four conditions are discussed that must be satisfied for this promise to be fulfilled. Since none of these conditions is satisfied, risk analysis does not keep its promise. In its attempts to reduce genuinely political issues to technocratic calculations, it neglects many of the factors that should influence decisions on risk acceptance. A list of tentative guidelines is (...) given for numerical decision support that encourages democratic decision‐making instead of trying to evade it. (shrink)

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. (shrink)

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. (shrink)

A representation theorem is obtained for contraction operators that are based on Levi's recent proposal that selection functions should be applied to the set of saturatable contractions, rather than to maximal subsets as in the AGM framework. Furthermore, it is shown that Levi's proposal to base the selection on a weakly monotonic measure of informational value guarantees the satisfaction of both of Gärdenfors' supplementary postulates for contraction. These results indicate that Levi has succeeded in constructing a well-behaved operation of contraction (...) that does not satisfy the postulate of recovery. (shrink)

The postulate of recovery is commonly regarded to be the intuitively least compelling of the six basic Gärdenfors postulates for belief contraction. We replace recovery by the seemingly much weaker postulate of core-retainment, which ensures that if x is excluded from K when p is contracted, then x plays some role for the fact that K implies p. Surprisingly enough, core-retainment together with four of the other Gärdenfors postulates implies recovery for logically closed belief sets. Reasonable contraction operators without recovery (...) do not seem to be possible for such sets. Instead, however, they can be obtained for non-closed belief bases. Some results on partial meet contractions on belief bases are given, including an axiomatic characterization and a non-vacuous extension of the AGM closure condition. (shrink)

This book explains how the logic of theory change employs formal models in the investigation of changes in belief states and databases. The topics covered include equivalent characterizations of AGM operations, extended representations of the belief states, change operators not included in the original framework, iterated change, applications of the model, its connections with other formal frameworks, and criticism of the model.

In order to explore the quantifiability and formalizability of uncertainty a wide range of uncertainties are investigated. They are summarized under eight main categories: factual, possibilistic, metadoxastic, agential, interactive, value, structural, and linguistic uncertainty. This includes both classical uncertainty and the uncertainties commonly called great, deep, or radical. For five of the eight types of uncertainty, both quantitative and non-quantitative formalizations are meaningful and available. For one of them (interactive uncertainty), only non-quantitative formalizations seem to be meaningful, and for two (...) (agential and structural uncertainty) neither quantitative nor non-quantitative formalization seems to be a useful approach. (shrink)

This paper summarizes and systematizes recent and ongoing work on non-prioritized belief change, i.e., belief revision in which the new information has no special priority due to its novelty.

A definition of pseudoscience is proposed, according to which a statement is pseudoscientific if and only if it (1) pertains to an issue within the domains of science, (2) is not epistemically warranted, and (3) is part of a doctrine whose major proponents try to create the impression that it is epistemically warranted. This approach has the advantage of separating the definition of pseudoscience from the justification of the claim that science represents the most epistemically warranted statements. The definition is (...) used to explain why proponents of widely divergent criteria for the demarcation between science and pseudoscience tend to be in almost complete agreement on the particular demarcations that should presumably be based on these general criteria. (shrink)

Due to modern biochemistry and, in particular, recent developments in genomics, proteomics, and bioinformatics, human samples have become the most important raw materials for advancement in the health sciences. Such material has been at the center of fundamental biomedical research for a long time. What is new is its increased usefulness in research with direct clinical relevance, such as the development of drugs. Because of the larger commercial involvement in such research, this has also led to greater economic interests in (...) human biological material and in the information that can be extracted from it. (shrink)

In standard Bayesian probability revision, the adoption of full beliefs (propositions with probability 1) is irreversible. Once an agent has full belief in a proposition, no subsequent revision can remove that belief. This is an unrealistic feature, and it also makes probability revision incompatible with belief change theory, which focuses on how the set of full beliefs is modified through both additions and retractions. This problem in probability theory can be solved in a model that (i) lets the codomain of (...) the probability function be a hyperreal-valued rather than the real-valued closed interval [0, 1], and (ii) identifies the full beliefs as the propositions whose probability is either 1 or infinitesimally smaller than 1. In this model, changes in the probability function will result in changes in the set of full beliefs (belief set), which constitutes a submodel that can be conceived as the “tip of the iceberg” within the larger model that also contains beliefs on lower levels of probability. The patterns of change in the set of full beliefs in this modified Bayesian model coincides with the corresponding pattern in a slightly modified version of AGM revision, which is commonly conceived as the gold standard of (dichotomous) belief change. The modification only concerns the marginal case of revision by an inconsistent input sentence. These results show that probability revision and dichotomous belief change can be unified in one and the same framework, or – if we so wish – that belief change theory can be subsumed under a modified version of probability revision that allows for iterated change and for the removal of full beliefs. (shrink)

Sweden is probably one of the most secularized nations in the world. Therefore religious arguments tend to play a smaller role in the public bioethical debate than in most other countries. Issues such as abortion, stem-cell research, and therapeutic cloning have been far less controversial in Sweden than elsewhere. Instead, other issues have dominated recent bioethical debates in Sweden, in particular those concerning privacy and the control over biological information about individuals.

Three of the bioethical issues recently discussed in Sweden appear to be particularly interesting also to an international audience. A new law allowing restrictive use of preimplantation genetic diagnosis /human leukocyte antigen () has been implemented, a new recommendation for the cessation of life-sustaining treatment has been issued, and the scope of individual responsibility for medical mistakes has been rather thoroughly discussed.

Five types of constructions are introduced for non-prioritized belief revision, i.e., belief revision in which the input sentence is not always accepted. These constructions include generalizations of entrenchment-based and sphere-based revision. Axiomatic characterizations are provided, and close interconnections are shown to hold between the different constructions.

An operator of contraction for a belief set (a theory) can be obtained by assigning to it a belief base and an operator of partial meet contraction for that base. It is argued that closure of the base under disjunction is an intuitively reasonable condition. Axiomatic characterizations are given of the contractions of belief sets that can be generated by (various types of) partial meet contraction on disjunctively closed bases. The corresponding revision operators are also characterized. Finally, some results are (...) reported on operations on bases that are closed under material implication. (shrink)

This article investigates the properties of multistate top revision, a dichotomous model of belief revision that is based on an underlying model of probability revision. A proposition is included in the belief set if and only if its probability is either 1 or infinitesimally close to 1. Infinitesimal probabilities are used to keep track of propositions that are currently considered to have negligible probability, so that they are available if future information makes them more plausible. Multistate top revision satisfies a (...) slightly modified version of the set of basic and supplementary AGM postulates, except the inclusion and success postulates. This result shows that hyperreal probabilities can provide us with efficient tools for overcoming the well known difficulties in combining dichotomous and probabilistic models of belief change. (shrink)

In order to explore public views on nanobiotechnology (NBT), convergence seminars were held in four places in Europe; namely in Visby (Sweden), Sheffield (UK), Lublin (Poland), and Porto (Portugal). A convergence seminar is a new form of public participatory activity that can be used to deal systematically with the uncertainty associated for instance with the development of an emerging technology like nanobiotechnology. In its first phase, the participants are divided into three “scenario groups” that discuss different future scenarios. In the (...) second phase, the participants are regrouped into three “convergence groups”, each of which contains representatives from each of the three groups from the first phase. In the final third phase, all participants meet for a summary discussion. This pilot project had two aims: (1) to develop and assess the new methodology and (2) to gather advice and recommendations from the public that may be useful for future decisions on nanobiotechnology (NBT). Participants emphasized that they wanted the technology to focus on solutions to environmental and medical problems and to meet the needs of developing countries. The need for further public participation and deliberation on NBT issues seemed to be acknowledged by all participants. Many of them also raised equality concerns. Views on the means by which NBT should be steered into socially useful directions were more divided. In particular, different views were expressed on how much regulation of company activities is needed to curb unwanted developments. The participants’ responses in a questionnaire indicate that the methodology of the convergence seminars was successful for decision-making under uncertainty. In particular, the participants stated that their advice was influenced both by access to different possible future developments and by the points of view of their co-participants, which is what the method is specifically intended to achieve. (shrink)

The 1985 paper by Carlos Alchourrón, Peter Gärdenfors, and David Makinson, “On the Logic of Theory Change: Partial Meet Contraction and Revision Functions” was the starting-point of a large and rapidly growing literature that employs formal models in the investigation of changes in belief states and databases. In this review, the first twenty-five years of this development are summarized. The topics covered include equivalent characterizations of AGM operations, extended representations of the belief states, change operators not included in the original (...) framework, iterated change, applications of the model, its connections with other formal frameworks, computatibility of AGM operations, and criticism of the model. (shrink)

Despite Vision Zero’s moral appeal and its expansion throughout the world, it has been criticized on different grounds. This chapter is based on an extensive literature search for criticism of Vision Zero, using the bibliographic databases Philosopher’s Index, Web of Science, Science Direct, Scopus, Google Scholar, PubMed, and Phil Papers, and by following the references in the collected documents. Even if the primary emphasis was on Vision Zero in road traffic, our search also included documents criticizing Vision Zero policies in (...) other safety areas, such as public health, the construction and mining industries, and workplaces in general. Based on the findings, we identify and systematically characterize and classify the major arguments that have been put forward against Vision Zero. The most important arguments against Vision Zero can be divided into three major categories: moral arguments, arguments concerning the rationality of Vision Zero, and arguments aimed at the practical implementation of the goals. We also assess the arguments. Of the 13 identified main arguments, 6 were found to be useful for a constructive discussion on safety improvements. (shrink)

The 1985 paper by Carlos Alchourrón (1931–1996), Peter Gärdenfors, and David Makinson (AGM), "On the Logic of Theory Change: Partial Meet Contraction and Revision Functions" was the starting-point of a large and rapidly growing literature that employs formal models in the investigation of changes in belief states and databases. In this review, the first twentyfive years of this development are summarized. The topics covered include equivalent characterizations of AGM operations, extended representations of the belief states, change operators not included in (...) the original framework, iterated change, applications of the model, its connections with other formal frameworks, computatibility of AGM operations, and criticism of the model. (shrink)

Available methods such as technology assessment and risk analysis have failed to predict the effects of technological choices. We need to give up the futile predictive ambitions of previous approaches and instead base decisions on systematic studies of alternative future developments. It will then be necessary to cope with mere possibility arguments, i.e., arguments in which a conclusion is drawn from a mere possibility that a course of action may have certain consequences. A five-step procedure is proposed for the assessment (...) of such arguments. It includes a search for mere possibility arguments pointing in different directions, a scientific evaluation that may lead to the specification or refutation of some of these arguments, two symmetry tests, evaluation of the seriousness of the arguments in terms of novelty, spatio-temporal unlimitedness and interference with complex systems, and hypothetical retrospection that aims at finding a course of action that will be defensible in retrospect. (shrink)

Blockage contraction is an operation of belief contraction that acts directly on the outcome set, i.e. the set of logically closed subsets of the original belief set K that are potential contraction outcomes. Blocking is represented by a binary relation on the outcome set. If a potential outcome X blocks another potential outcome Y, and X does not imply the sentence p to be contracted, then Y ≠ K ÷ p. The contraction outcome K ÷ p is equal to the (...) (unique) inclusion-maximal unblocked element of the outcome set that does not imply p. Conditions on the blocking relation are specified that ensure the existence of such a unique inclusion-maximal set for all sentences p. Blockage contraction is axiomatically characterized and its relations to AGM-style operations are investigated. In a finite-based framework, every transitively relational partial meet contraction is also a blockage contraction. (shrink)

abstract Even though much research has been devoted to studies of safety, the concept of safety is in itself under‐theorised, especially concerning its relation to epistemic uncertainty. In this paper we propose a conceptual analysis of safety. The paper explores the distinc‐tion between absolute and relative safety, as well as that between objective and subjective safety. Four potential dimensions of safety are discussed, viz. harm, probability, epistemic uncertainty, and control. The first three of these are used in the proposed definition (...) of safety, whereas it is argued that control should not be included in a reasonable definition of safety. It is shown that strictly speaking, an objective safety concept is not attainable. Instead, an intersubjective concept is proposed that brings us as close as possible to an objective concept. (shrink)

A new equivalent presentation of AGM revision is introduced, in which a preference-based choice function directly selects one among the potential outcomes of the operation. This model differs from the usual presentations of AGM revision in which the choice function instead delivers a collection of sets whose intersection is the outcome. The new presentation confirms the versatility of AGM revision, but it also lends credibility to the more general model of direct choice among outcomes of which AGM revision is shown (...) here to be a special case. (shrink)

A general theory of coherence is proposed, in which systemic and relational coherence are shown to be interdefinable. When this theory is applied to sets of sentences, it turns out that logical closure obscures the distinctions that are needed for a meaningful analysis of coherence. It is concluded that references to “all beliefs” in coherentist phrases such as “all beliefs support each other” have to be modified so that merely derived beliefs are excluded. Therefore, in order to avoid absurd conclusions, (...) coherentists have to accept a weak version of epistemic priority, that sorts out merely derived beliefs. Furthermore, it is shown that in belief revision theory, coherence cannot be adequately represented by logical closure, but has to be represented separately. (shrink)

We introduce a constructive model of selective belief revision in which it is possible to accept only a part of the input information. A selective revision operator ο is defined by the equality K ο α = K * f(α), where * is an AGM revision operator and f a function, typically with the property ⊢ α → f(α). Axiomatic characterizations are provided for three variants of selective revision.

A possible world semantics for preference is developed. The remainder operator () is used to give precision to the notion that two states of the world are as similar as possible, given a specified difference between them. A general structure is introduced for preference relations between states of affairs, and three types of such preference relations are defined. It is argued that one of them, actual preference, corresponds closely to the concept of preference in informal discourse. Its logical properties are (...) studied and shown to be plausible. (shrink)

Should Probabilistic Design Replace Safety Factors? Content Type Journal Article Pages 151-168 DOI 10.1007/s13347-010-0003-6 Authors Neelke Doorn, Department of Technology, Policy and Management, Delft University of Technology, PO Box 5015, 2600 GA Delft, The Netherlands Sven Ove Hansson, Department of Philosophy and the History of Technology, Royal Institute of Technology, Teknikringen 78 B, 100 44 Stockholm, Sweden Journal Philosophy & Technology Online ISSN 2210-5441 Print ISSN 2210-5433 Journal Volume Volume 24 Journal Issue Volume 24, Number 2.

A value statement such as “she is a good teacher” is categoryspecified, i.e., the criteria of evaluation are specified as those that are applicable to a given category, in this case the category of teachers. In this study of categoryspecified value statements, certain categories are identified that cannot be used to specify value aspects. Special attention is paid to categories that are constituted by functional characteristics. The logical properties of value statements that refer to such categories are shown to differ (...) significantly from the corresponding properties in social choice theory. (shrink)

We can often specify how we would contract by a certain sentence by saying that this contraction would coincide with some other contraction that we know how to perform. We can for instance clarify that our contraction by p&q would coincide with our contraction by p, or by q, or by {p, q}. In a framework where the set of potential outcomes is known, some contractions are “self-evident” in the sense that there is only one serious candidate that can be (...) the outcome of such a contraction. Contraction by a specific contractee (sentence or set of sentences to be contracted) is bootstrapped if it is specified by saying that it coincides with some such self-evident contraction. For a wide range of (multiple) contraction operators, contractions by any contractee can be bootstrapped. This means that the selection mechanism (selection function, incision function, etc.) can be replaced by a function called a bootstrapping selector that assigns to each contractee some “self-evident” contractee that yields the same outcome. With bootstrapping we can eliminate traditional extralogical components in contraction (e.g., selection functions) and replace them by bootstrapping selectors that reflect more closely the ways in which we actually reason and argue about belief contraction. (shrink)

Blockage revision is a version of descriptor revision, i.e. belief change in which a belief set K is changed with inputs whose success conditions are metalinguistic expressions containing the belief predicate \. This is a highly general framework that allows a single revision operator \ to take inputs corresponding to sentential revision ), contraction ) as well as more complex and composite operations. In blockage revision, such an operation is based on a relation \ of blockage among the set of (...) potential outcomes. \ signifies that if X satisfies the success condition of a belief change, then Y cannot be its outcome. The properties of blockage revision are investigated, and conditions on the blocking relation are specified that characterize various properties of the resulting operation of change. (shrink)