One of the most important themes in this book is the theme of fire. First, the title of the book has to do with the mind on fire. This foreshadows the use of fire as a theme throughout this book. This fire has to do with power and energy. Emerson's mind was on fire throughout much of his life. As the author states in the Preface, Emerson's private and professionals lives were intertwined; a biography about Emerson's career would be incomplete without his personal life. This fire, or energy, filled Emerson as a child in a family that put importance on education, when he studied in college and was inspired by various writers and professors as a young man.