John Stuart Mill was one of the greatest thinkers of the nineteenth century. His impact on modern culture and thought has been immense, and his continuing importance for contemporary philosophy and social thought is widely recognized. This companion furnishes the reader with a systematic and up-to-date account of the many facets of Mill's thought and influence. New readers will find this the most convenient and accessible guide to Mill currently available. Advanced students and specialists will find a conspectus of recent developments in the interpretation of Mill.