In a paper and a reply to critics published in _Informal Logic_, I argue that arguments from expert opinion are weak arguments. To appeal to expert opinion is to take an expert’s judgment that _p_ is the case as evidence for _p_. Such appeals to expert opinion are weak, I argue, because the fact that an expert judges that _p_ does not make it significantly more likely that _p_ is true or probable, as evidence from empirical studies on expert performance (...) suggests. Unlike other critics of this argument, who take issue with the empirical evidence on expert performance, David Botting says that he wants to take issue with the premise that reliability is a necessary condition for the strength of appeals to expert opinion. I respond to Botting’s objections and argue that they miss their intended target. I also argue that his attempt to show that arguments from expert opinion are strong is unsuccessful. (shrink)

Accounts of arguments from expert opinion take it for granted that expert judgments count as (defeasible) evidence for propositions, and so an argument that proceeds from premises about what an expert judges to a conclusion that the expert is probably right is a strong argument. In Mizrahi (2013), I consider a potential justification for this assumption, namely, that expert judgments are significantly more likely to be true than novice judgments, and find it wanting because of empirical evidence suggesting that expert (...) judgments under uncertainty are not significantly more likely to be true than novice judgments or even chance. In this paper, I consider another potential justification for this assumption, namely, that expert judgments are not influenced by the cognitive biases novice judgments are influenced by, and find it wanting, too, because of empirical evidence suggesting that experts are vulnerable to pretty much the same cognitive biases that novices are vulnerable to. If this is correct, then the basic assumption at the core of accounts of arguments from expert opinion, namely, that expert judgments count as (defeasible) evidence for propositions, remains unjustified. (shrink)

In one of his papers, Moti Mizrahi argues that arguments from an expert opinion are weak arguments. His thesis may seem controversial due to the consensus on this topic in the field of informal logic. I argue that its controversy is framework-dependent, and if translated into a different framework, it appears to be a correct, however trivial, claim. I will use a framework based on Douglas Walton’s argumentation scheme theory and his conception of examination dialogue to demonstrate that it is (...) so. It appears that Mizrahi’s idiosyncratic framework provides an excessively restrictive conception of an argument from expert opinion than Walton’s scheme does. There is no quarrel between both frameworks, as they yield analogous, almost identical, outcomes of argument evaluation. The actual and crucial disagreement is on the topic of argument classification. Mizrahi’s conception of arguments from an expert opinion imposes exact conditions that such argument must fulfil: an expert’s opinion o truth-value must be unknown; o must be unsupported by any evidence; an expert’s peers neither accept o nor reject it. These exclude, by definition, every possible strong, in Walton’s terms, variant of such an argument. Therefore, if rephrased with the notions of the examination dialogue framework, Mizrahi’s thesis sounds as follows: weak arguments from expert opinion are weak arguments. (shrink)

Recent disputes :57–79, 2013; Mizrahi in Inform Logic 36:238–252, 2016; Mizrahi in Argumentation 32:175–195, 2018; Seidel in Inform Logic 34:192–218, 2014; Seidel in Inform Logic 36:253–264, 2016; Hinton in Inform Logic 35:539–554, 2015) on the strength of arguments from expert opinion give rise to a potential legitimacy crisis of it. Mizrahi :57–79, 2013; Inform Logic 36:238–252; Argumentation 32:175–195, 2018) claims that AEO are weak arguments by presenting two independent arguments. The first argument is that AEO are weak arguments because empirical (...) studies show that expert opinions p do not make p significantly more likely to be true. The second argument is that AEO are weak arguments because empirical studies show that expert opinions are susceptible to the kinds of cognitive biases that novice opinions are susceptible to. In this paper, I intend to argue that Mizrahi’s two arguments both fail because of inconsistency, irrelevance, and insufficiency. Nevertheless, Mizrahi’s arguments help to evaluate AEO better by expanding the relevant critical questions. (shrink)

ABSTRACTIn order to properly understand how expert disagreement should be dealt with, it is essential to grasp how expert opinion is used in the reasoning process by which humans reach conclusions and make decisions. This paper utilises the tools of argumentation theory, specifically Douglas Walton’s argument schemes, and variations upon them, in order to examine how patterns of reasoning are affected by the presence of conflicting testimony. This study suggests that although it may be supplemented with the construction of epistemic (...) hierarchies, the scheme of reasoning for the appeal to expert opinion provides no mechanism for establishing a preference for one expert statement over another, making it impossible to reach any rational conclusion as to the likely truth of the matter. Further, it is also argued that other schemes for presumptive argumentation are either unhelpful in themselves or lead to unwanted consequences. (shrink)

In this paper I will argue that there is an inductive and a non-inductive argument from position to know, and will characterise the latter as an argument from authority because of providing content-independent reasons. I will also argue that both types of argument should be doubt-preserving: testimony cannot justify a stronger cognitive attitude in the arguer than the expert herself expresses when she testifies. Failure to appreciate this point undercuts Mizrahi’s claim that arguments from expert opinion are weak.