Sven Ove Hansson

Contrary to the received view, decision theory is not primarily devoted to instrumental (ends-to-means) reasoning. Instead, its major preoccupation is the derivation of ends from other ends. Given preferences over basic alternatives, it constructs preferences over alternatives that have been modified through the addition of value object modifiers (modes) that specify probability, uncertainty, distance in time etc. A typology of the decision-theoretical modes is offered. The modes do not have (even extrinsic) value, but they transform the value of objects to which they are applied. A rational agent's total set of preferences should be coherent, but from this it does not follow that her preferences over mode-containing objects have to be derivable from her preferences over mode-free objects.

Analytical tools that give precision to the concept of "independence of syntax" are developed in the form of a series of substitutivity principles. These principles are applied in a study of the rôle of language in belief revision theory. It is shown that sets of sentences can be used in models of belief revision to convey more information than what is conveyed by the combined propositional contents of the respective sets. It is argued that it would be unwise to programmatically restrain the use of sets of sentences to that of representing propositional contents. Instead, the expressive power of language should be used as fully as possible. Therefore, syntax-independence should not be seen as a criterion of adequacy for language-based models of information-processing, but rather as a property that emerges from some but not all the idealization processes through which such models are constructed.

When presented with a situation involving an agent’s choice between alternative actions, a moral oracle says what the agent is allowed to do. The oracle bases her advice on some moral theory, but the nature of that theory is not known by us. The moral oracle’s test consists in determining whether a series of questions to the oracle can be so constructed that her answers will reveal which of two given types of theories she adheres to. The test can be applied to moral theories in order to determine if they differ in their recommendations for action. Based on this test, a terminology is developed to specify different forms and degrees of distinguishability between moral theories, or types of theories, in terms of their recommendations for action. In conclusion, the test is applied to consequentialism and utilitarianism.

Ethicists have investigated ethical problems in other disciplines, but there has not been much discussion of the ethics of their own activities. Research in ethics has many ethical problems in common with other areas of research, and it also has problems of its own. The researcher’s integrity is more precarious than in most other disciplines, and therefore even stronger procedural checks are needed to protect it. The promotion of some standpoints in ethical issues may be socially harmful, and even our decisions as to which issues we label as “ethical” may have unintended and potentially harmful social consequences. It can be argued that ethicists have an obligation to make positive contributions to society, but the practical implications of such an obligation are not easily identified. This article provides an overview of ethical issues that arise in research into ethics and in the application of such research. It ends with a list of ten practical proposals for how these issues should be dealt with.

ConclusionUnlike the more commonly discussed paradoxes of deontic logic, the revenger's paradox is present not only in strong logics such as SDL, but also in much weaker logics that have been constructed to avoid the paradoxes of SDL. The paradox shows that any deontic logic with intersubstitutivity makes counter-intuitive truth assignments to some deontic expressions.However, the revenger's paradox does not pose as serious a problem as does Ross's paradox to the logics in which it occurs. A deontic logic in which Ross's paradox does not arise is preferable to one in which it does arise, even if the latter is subject to the revenger's paradox.

The maximin rule can be used as a formal version of the precautionary principle. This paper evaluates the feasibility and the intuitive plausibility of this decision rule. The major conclusions are: (1) Precaution has to be applied symmetrically. (2) Precaution is only possible when outcomes are comparable in terms of value, so that it can be determined which outcome is worst. (3) Precaution is sensitive to standards of possibility. Far-away scenarios have to be excluded, and it is difficult to find a principled way to draw the line. (4) Precaution is sensitive to the framing of decision problems. Local cautiousness may add up to global incautiousness.

The purpose of this presentation is to introduce both the concept of risk and the precautionary principle, that is a major policy principle in present-day risk management. Since risk has been the subject of many misconceptions I will do this in large part by criticizing seven views on risk that I believe to have caused considerable confusion both among scientists and policy-makers. But before looking at the seven myths of risk, let us begin with the basic issue of defining “risk”. The word “risk” often refers, rather vaguely, to situations in which it is possible but not certain that some undesirable event will occur. In addition, the word has several more specialized meanings. Let me illustrate this by making a few statements about the single most important preventable health hazard in non-starving countries. First: “Lung cancer is one of the major risks that affect smokers.” Here, we use “risk” in the following sense: (1) risk = an unwanted event which may or may not occur. 1 (15).

Specified meet contraction is the operation defined by the identity where ∼ is full meet contraction and f is a sentential selector, a function from sentences to sentences. With suitable conditions on the sentential selector, specified meet contraction coincides with the partial meet contractions that yield a finite-based contraction outcome if the original belief set is finite-based. In terms of cognitive realism, specified meet contraction has an advantage over partial meet contraction in that the selection mechanism operates on sentences rather than on temporary infinite structures (remainders) that are cognitively inaccessible. Specified meet contraction provides a versatile framework in which other types of contraction, such as severe withdrawal and base-generated contraction, can be expressed with suitably chosen properties of the sentential selector.