• Analysis of 108 sworn canonical depositions reveals a coherent behavioral corpus. • Recurrent, stereotyped episodes shows stable convergence with modern epilepsy semiology. • Statistical analysis does not support feigning as a sufficient explanatory model. • Episodes produced sustained functional impairment and institutional intervention.• Provides a structured framework for clinical interpretation of historical mystic phenomena. This study analyzes a corpus of seventeenth-century sworn eyewitness depositions concerning the Franciscan friar Joseph of Copertino (1603–1663) to assess whether the behavioral descriptions they contain correspond to features recognized in modern neurological and psychiatric semiology. Joseph’s episodes were documented during formal ecclesiastical investigations, producing an unusually detailed body of contemporaneous testimony. We analyzed 103 canonical eyewitness depositions, comprising testimonies both with and without alleged aerial motion, recorded by observers lacking a conceptual framework for modern nonconvulsive seizure states. Recurrent behavioral features were examined in relation to contemporary neurological and psychiatric semiology, including epileptic and non-epileptic seizure frameworks, without attempting retrospective diagnosis. Statistical testing did not support the feigning mechanism proposed in a skeptical critique as a sufficient explanation for the reported aerial elevations. Descriptive analysis revealed a recurrent semiological constellation across multiple witnesses, contexts, and decades, including abrupt loud vocalization at episode onset, motion arrest, maintained posture with open eyes, reduced responsiveness, repetitive motor and verbal behavior, and precise resumption of previously interrupted activity in several accounts. Episodes produced functional consequences, including interruption of religious duties and enforced seclusion. Although historical analysis precludes clinical diagnosis and does not exclude psychogenic, cultural, or theological interpretations, the convergence of multiple recorded semiological features is compatible with epileptic semiology, although some features remain open to alternative interpretations. Canonical testimony, analyzed with methodological restraint, may therefore function as inadvertent clinical observation in interdisciplinary historical research.
Costa et al. (Sun,) studied this question.