Mental measurement and the introspective privilege

Abstract

Abstract According to a long-standing belief, introspection provides privileged access to the mind, while objective methods, which we denote as “extrospection”, suffer from basic epistemic deficits. Here we will argue that neither an introspective privilege exists nor does extrospection suffer from such deficits. We will focus on two entailments of an introspective privilege: first, such a privilege would require that introspective evidence prevails in cases of conflict with extrospective information. However, we will show that this is not the case: extrospective claims can prevail in cases of conflict. These conflicts are resolved by an inference to the explanation that best accounts for the available evidence. This explanation may speak in favor of extrospection. Second, given an introspective privilege, the development of extrospective measurement techniques should be restricted by the accuracy of introspective reports. We will argue that this problem is part of a more general issue that comes up with the establishment of measurement in the natural sciences. We will identify three strategies that have proven successful in dealing with the problem in the natural sciences. It will turn out that all these strategies are available for extrospective measurement as well. Consequently, the insufficiencies of introspective reports do not impose a limit on the accuracy of extrospective measurement methods. We conclude that neither an introspective privilege nor basic extrospective deficits exist. This does not mean that extrospection will ever replace introspection. Rather, both approaches provide independent and indispensable forms of epistemic access to the mind.