While most discussions of liberty center on government power, the subject of Mill's essay is the nature and limits of society's power over the individual. Society exercises control over the individual through prevailing opinion. Mill also argues that individuals should be allowed to participate in any activity they choose, so long as it does not harm others.

While most discussions of liberty center on government power, the subject of Mill's essay is the nature and limits of society's power over the individual. Society exercises control over the individual through prevailing opinion. Mill also argues that individuals should be allowed to participate in any activity they choose, so long as it does not harm others.