"A History of the Inquisition of Spain; vol. 4" by Henry Charles Lea is a historical account written in the early 20th century. This volume delves into the complexities of mysticism and the Inquisition's reactions to various spiritual movements, exploring the intersections of faith, authority, and dissent within the context of Spanish religious history. Lea examines the nuances of how mystics, their practices, and their theological beliefs were perceived and treated by the Inquisition. At the start of this volume, the author outlines the foundational concepts of mysticism, tracing its historical roots and prominence in spiritual practices. He discusses the dangers associated with mysticism, particularly how its followers sometimes diverged from orthodox religious teachings, leading to persecution by the Inquisition. Through detailed accounts of notable figures, including Francisca Hernández and María Cazalla, and their trials, the opening portion illustrates the conflict between mysticism and the church's authority, setting the stage for an exploration of the complex relationship between spirituality and institutional power. (This is an automatically generated summary.)