Lena Wahlberg

Fallacies in ad hominem arguments

Arguments ad hominem are common in political debates, legal argumentation and everyday conversations. In this article, we propose a general definition of ad hominem arguments. An argument ad hominem is an argument that makes a claim about the reliability of a person in the performance of a certain function, based on some attribute relating to the person in question. On the basis of this definition, we examine the different ways that ad hominem arguments can go wrong, and classify them as seven different ad hominem fallacies: false attribution, irrelevant attribute, overrated effect, reliability irrelevance, irrelevant person, insufficient degree and irrelevant function. The various fallacies are illustrated with examples from politics, law and everyday life.

Importing notions in health law: science and proven experience

In Swedish law, the notion of ‘science and proven experience’ (in Swedish, vetenskap och beprovad erfarenhet) defines the gold standard for public decision-making and practice, especially in medicine. The notion is notoriously vague but nevertheless plays an important role in the distribution of rights and duties of patients and healthcare workers. For example, failure to provide care in accordance with this standard can lead to penal responsibility. The notion also helps to define Swedish patients’ right to reimbursement for cross-border healthcare. From a legal point of view, the notion is especially intriguing because it appears to import medical standards into the legal conceptual apparatus. The purpose of this article is to explore the mechanisms of this andkindred ‘importing notions’ by investigating the role that the notion of science and proven experience plays in Swedish law and in the transfer of information between the legal and medical fields. (Less)

Legal Ontology, Scientific Expertise and the Factual World

Abstract This article analyses the role of scientific information in legal proceedings by exploring the relationship of law, science and the factual world. The article compares legal and scientific ontology, and discusses how they relate to each other. The comparison is used to explain previous controversies between legal and scientific experts. Special consideration is devoted to the legal notion of cause-in-fact, which is discussed at length. The article distinguishes among different meanings of “facticity” in the legal discourse on causation, and discusses the bearing that these meanings have on the legal relevance of scientific information.

Science and proven experience : a Swedish variety of evidence based medicine and a way to better risk analysis?

Abstract A key question for evidence-based medicine (EBM) is how best to model the way in which EBM should ‘[integrate] individual clinical expertise and the best external evidence’. We argue that the formulations and models available in the literature today are modest variations on a common theme and face very similar problems when it comes to risk analysis, which is here understood as a decision procedure comprising a factual assessment of risk, the risk assessment, and the decision what to do based on this assessment, the risk management. Both the early and updated models of evidence-based clinical decisions presented in the writings of Haynes, Devereaux and Guyatt assume that EBM consists of, among other things, evidence from clinical research together with information about patients’ values and clinical expertise. On this A-view, EBM describes all that goes on in a specific justifiable medical decision. There is, however, an alternative interpretation of EBM, the B-view, in which EBM describes just one component of the decision situation (a component usually based on evidence from clinical research) and in which, together with other types of evidence, EBM leads to a justifiable clincial decision but does not describe the decision itself. This B-view is inspired by a 100-years older version of EBM, a Swedish standard requiring medical decision-making, professional risk-taking and practice to be in accordance with ‘science and proven experience’ (VBE). In the paper, we outline how the Swedish concept leads to an improved understanding of the way in which scientific evidence and clinical experience can and cannot be integrated in light of EBM. How scientific evidence and clinical experience is integrated influences both the way we do risk assessment and risk management. In addition, the paper sketches the as yet unexplored historical background to VBE and EBM.

Prototype Effect and the Persuasiveness of Generalizations.

An argument that makes use of a generalization activates the prototype for the category used in the generalization. We conducted two experiments that investigated how the activation of the prototype affects the persuasiveness of the argument. The results of the experiments suggest that the features of the prototype overshadow and partly overwrite the actual facts of the case. The case is, to some extent, judged as if it had the features of the prototype instead of the features it actually has. This prototype effect increases the persuasiveness of the argument in situations where the audience finds the judgment more warranted for the prototype than for the actual case (positive prototype effect), but decreases persuasiveness in situations where the audience finds the judgment less warranted for the prototype than for the actual case (negative prototype effect).

Appeal to expert testimony - A Bayesian approach

In this chapter, we offer a Bayesian model for evaluating expert testimony in the court room. Statements from a putative expert are difficult for a legal decision maker to assess, as the legal decision maker – who lacks expert knowledge on the subject issue – must distinguish between experts that are highly reliable and experts that are less reliable. A methodology for the assessment of the expert testimony has been suggested previously, in the works of Walton and Goldman, and we develop this methodology further, using a Bayesian approach to reliability assessment. The reliability of an expert can be questioned on different grounds (lack of competence, bias and lack of motivation), and we clarify different effects that these grounds can have on the expert’s reliability.