Chapter 2 of On Liberty, titled ‘Of the Liberty of Thought and Discussion’, develops a well-known epistemic argument for free speech. While it makes a plausible case for open-mindedness and diversity of opinion, it also appears to encapsulate some of the flaws that critics attribute to ‘free speech ideology’. This paper defends On Liberty against this criticism and proposes a new interpretation of the chapter’s objectives and its contemporary relevance, the power-critical account. While I conclude that chapter 2 fails to show that it is always epistemically harmful to silence opinions, I defend the Millian idea that a robust principle of speaker immunity is required for the transition to an ideal, reflectively stable society.
