The three parts of the book set Thelwall's achievements and challenges in the political and literary context of his times. Part One, "Jacobin(s) Writing," focuses on the most essential aspects, ideologically and formally, of the insurgent writing of the 1790s to which Thelwall contributed. Part Two, "The Voice of the People," treats both Thelwall's radical oratory and journalism, as well as his writings and activities as a natural scientist and rhetorician, a professor and technician of "elocution." Part Three, "Jacobin Allegory," expounds on Thelwall's characteristic strategy of indirect expression through synecdoche and allegory, which he used in his later career after repression forced him out of politics.

Through Thelwall's life Michael Scrivener succeeds in revealing how British Jacobinism reshaped the public sphere, initiating numerous literary experiments with oratory, pamphlets, periodicals, popularizations, and songs in the spaces opened up by political associations, lectures, meetings, and trials. Jacobinism thus altered the very institutions of reading and writing by expanding literacy, restructuring the popular arena for reading, and generating a body of diverse texts that were "seditious allegories."