Rethinking Expert Opinion Evidence as an Argument from Epistemic Authority

Abstract

In the modern age dominated by technical thinking and overabundance of information, judges, as never before, have become dependent on expert witness opinions without having necessary assessment tools at their disposal. Legal dogmatics, especially that of civil law procedure and penal law procedure, needs data feedback from argumentation theory to be used to augment and change the existing legal order concerning court expert institution, and to provide basis for developing techniques that could help lay people in the court environment in evaluation of experts and their opinions in a way inaccessible for legal dogmatics alone. On the other hand, it should be stressed that every theory of legal argumentation always has to take into consideration a given legal culture with its traditions, values, rules and legal science. The tools that are used to accomplish this are based on Douglas Walton’s logical argumentation, Bayesian probability and Bayesian belief networks. The author’s own way of combining Bayesian network with Walton’s critical questions method is viewed as a new tool that employs a questionnaire to gather data to be subsequently used in Bayes theorem calculations. The degree to which the argumentation theory tools prove to be useful depends on the amount of data gathered during the argumentation evaluation and the number of opportunities when dialectical critical testing can be performed.