The Secret Codes of the Mind: From Medieval Philosophy to the Enlightenment, Volume IV, Part Three (The Age of Enlightenment) examines the Enlightenment through the transformation of ideas about reason, freedom, political authority, knowledge, conscience, and human perfectibility. The volume begins with Voltaire and his defense of reason and toleration against fanaticism and inherited authority. It then turns to Jean-Jacques Rousseau and Montesquieu, examining competing approaches to freedom, law, political order, sovereignty, and the conditions under which legitimate authority can be established and restrained. The discussion continues with Denis Diderot and the encyclopedic project, exploring the organization and dissemination of knowledge, philosophical critique, and the challenge that independent inquiry poses to established intellectual authority. The concluding section examines Grigory Skovoroda and Freemasonry, through which questions of conscience, self-knowledge, moral formation, inner freedom, toleration, and human brotherhood acquire a different philosophical form. Across these discussions, the Enlightenment emerges as an intellectual struggle over the right of reason to judge authority and the possibility of transforming both political institutions and the individual. Each lecture includes questions and assignments designed to support philosophical analysis, together with recommended literature for further study. ( direct link )