A background assumption of this paper is that the repertoire of inference schemes available to humanity is not fixed, but subject to change as new schemes are invented or refined and as old ones are obsolesced or abandoned. This is particularly visible in areas like health and environmental sciences, where enormous societal investment has been made in finding ways to reach more dependable conclusions. Computational modeling of argumentation, at least for the discourse in expert fields, will require the possibility of (...) modeling change in a stock of schemes that may be applied to generate conclusions from data. We examine Randomized Clinical Trial, an inference scheme established within medical science in the mid-20th Century, and show that its successful defense by means of practical reasoning allowed for its black-boxing as an inference scheme that generates (and warrants belief in) conclusions about the effects of medical treatments. Modeling the use of a scheme is well-understood; here we focus on modeling how the scheme comes to be established so that it is available for use. (shrink)

This article seeks, first, to show that much of the existing normative work on argument from expert opinion (AEO) is problematic for failing to be properly informed by empirical findings on expert performance. Second, it seeks to show how, with the analytic tool of Bayesian reasoning, the problem diagnosed can be remedied to circumvent some of the problems facing the scheme-based treatment of AEOs. To establish the first contention, we will illustrate how empirical studies on factors conditioning expert reliability can (...) be drawn upon to re-construct. Walton’s critical questions matching the scheme of AEOs. To establish the second contention, we will illustrate how Walton’s re-constructed set of critical questions can be formalized within a Bayesian network. Finally, we will highlight how the specific ways in which the Bayesian framework we propose is both continuous with and distinct from the models of source reliability put forward by theorists like Bovens and Hartmann (2003). (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.

A background assumption of this paper is that the repertoire of inference schemes available to humanity is not fixed, but subject to change as new schemes are invented or refined and as old ones ar...

Authority arguments generate support for claims by appealing to an agent’s authority status, rather than to reasons independent of it. With few exceptions, the current literature on argument schemes acknowledges two basic authority types. The _epistemic_ type grounds in knowledge, the_ deontic_ type grounds in power. We review how historically earlier scholarship acknowledged an_ attractiveness-based_ and a _majority-based_ authority type as equally basic type. Crossing these with basic speech act types thus yields authority argument sub-schemes. Focusing on the_ epistemic-assertive_ sub-scheme (...) (‘an epistemic authority _A_ _E_ asserts a proposition _P_’), we apply a meta-level approach to specifying critical questions. Results improve the evaluation of this sub-scheme and show how similar improvements are obtainable for other schemes. (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)

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)