‘Every expression is watched’: Mind, medical expertise and display in the nineteenth

The growing presence of medical experts in the English courtroom during the early nineteenth century presented new challenges with regard to how those experts would exert their authority in an adversarial setting. This article examines the ways in which mental science practitioners responded when confronted with the need to testify as to the soundness or unsoundness of mind of an individual in the context of a legal proceeding. It argues that they often engaged in ‘a double act of self-fashioning’. On the one hand, they attempted to fashion their personae into representations of truth-telling beings; on the other hand, they sought to present testimony in such a way that the judge or jury could diagnose the individual’s alleged soundness or unsoundness of mind for themselves, and they sought to do this without leaving any trace of their own efforts. The procedures and presumptions of the English courtroom thus created an epistemic space in which physicians (and other scientific experts) were frequently presented with the puzzle of how to translate determinations arrived at on the basis of often recondite professional knowledge and years of experience into manifestations that could be made visible to a lay audience. Moreover, they had to do this in a setting in which every significant claim was likely to be disputed by adversary counsel and rival experts