Question: In which publication did the great 19ty-century liberal philosopher John Stuart Mill explain the harm principle, of exercising power over others only to protect them from harm?
Sentence (from "The Limits of State Action"): The Limits Of State Action is a philosophical treatise by Wilhelm von Humboldt, which is a major work of the German Enlightenment and the most significant source for the ideas which John Stuart Mill popularized in his essay "On Liberty".
Relevant evidence: No