In the rich history of political philosophy, great minds have sought to define the nature and extent of human freedom, with careful justifications offered for the principles proposed. This tradition experienced a heightened degree of enthusiastic intensity upon the publication of On Liberty in England during the nineteenth century. In this, his most powerful essay, John Stuart Mill defends individual liberty against both social and political encroachment, by daring to suggest that lines of demarcation be drawn to outline the proper role of government with respect to individual freedom. Appropriate spheres of action are offered for individuals, society, and the state; basic rules are established to deal with those cases in which human action may need to be restrained or limited. Mill’s eloquence and his unwavering dedication to the cause of freedom permeate every page.