One of the constant fascinations Mill holds for the general public as well as scholars derives from the early flowering of his genius. This development is seen in detail in the journal and notebook he kept in France during his fifteenth year, and in the debating speeches and walking-tour journals dating from his eighteenth to twenty-fourth years. This was the period when he first adopted Benthamism as 'a religion,' worked intensively as a propagandist for the faith, and then began the painful reassessment that led to his independent mature thought and action. Some of the results of that reassessment are seen in the diary entries from 1854, written for his wife, which reveal in personal form many of their most passionately held ideas. These materials have never before been gathered, and almost all appear here for the first time in scholarly form. They throw light on contemporary social interests and behavior, and will encourage new assessments of Mill’s life and thought. The texts, the great majority drawn from manuscripts, are presented in critical form, collated, with explanatory and textual notes. The Introduction gives the personal and historical context, with an analysis of content and rhetoric; the Textual Introduction supplies information about the nature and history of the documents, while Appendices provide ancillary materials. Both bibliographic and analytic indexes are included.