When the officials of any government seek to change the laws that regulate individual liberty or when rhetoricians seek to change public opinion about what individuals should or should not be allowed to say or do, Mill's On Liberty serves as an effective antidote to the poisons of excessive intrusion into the lives of individuals. The present edition is specifically designed to employ the dual nature of rhetoric — oral and written language — and to utilize electronic technology to open Mill's text to contemporary listeners as well as readers.

English, like all natural languages, changes over time. Some aspects of Mill's 19th century prose have shifted in meaning, leading to confusion and misunderstanding. His frequent use of long and indirect sentences distorts the clarity and logical precision of his ideas. The sexist language that was customary in his day violates one of Mill's most fundamental principles, developed so forcefully in The Subjection of Women, which he wrote in 1861. Our revision seeks to capture the spirit and meaning of Mill's philosophy while overcoming those difficulties. The text is unabridged. We have sought to render Mill's words in a form that brings a living presence to ideas that are vital for life itself.