John Stuart Mill is—surprisingly—a difficult writer. He writes clearly, non-technically, and in a very plain prose which Bertrand Russell once described as a model for philosophers. It is never hard to see what the general drift of the argument is, and never hard to see which side he is on. He is, none the less, a difficult writer because his clarity hides complicated arguments and assumptions which often take a good deal of unpicking. And when we have done that unpicking, the task of analysing the merits and deficiencies of the arguments is still only half completed. This is true of all his work and particularly true of Liberty. It is an essay whose clarity and energy have made it the most popular of all Mill's work. Yet it conceals philosophical, sociological and historical assumptions of a very debatable kind. In his introduction, Mill says

the object of this essay is to defend one very simple principle, as entitled to govern absolutely the dealings of society with the individual in the way of compulsion and control, whether the means used be legal penalties, or the moral coercion of public opinion (Liberty, 68).