John Stuart Mill's defense of freedom of discussion in On Liberty remains a major influence on philosophical and public debates about free speech. By highlighting underappreciated textual evidence and key distinctions, this introduction attempts to show how the contributions of the symposium authors – Melina Constantine Bell, Rafael Cejudo, Christopher Macleod, and Dale E. Miller – point toward a more complete account of Mill's views.

I consider whether Mill intends for us to see the arguments that constitute his defense of the “Liberty of Thought and Discussion” in chapter 2 of On Liberty as a part of his larger case for the “harm” or “liberty” principle (LP). Several commentators depict this chapter as a digression that interrupts the flow between his introduction of this principle in the first chapter and his exposition and defense of it in the final three. I will argue instead for a reading of On Liberty on which chapter 2 is well integrated with the rest of the essay and is in fact where Mill starts constructing his case for LP.

In this article, I offer a reading of On Liberty II which focuses on the structural features of the argument that Mill presents. Mill's argument, I suggest, is grounded on an appeal to the value of truth, and is divided into three sub-arguments, treating true, false and partially true opinion respectively. In section 1, I consider what constraints the teleological orientation of Mill's argument places on the case he makes, before examining in section 2 what the division of Mill's argument into three exhaustive sub-arguments tells us about the nature of ‘discussion’ as Mill uses the term. I go on, in section 3, to suggest that although On Liberty II does not offer a defence of free speech in the broad sense in which the term is often now used, we should be optimistic about the chances of finding such a defence in On Liberty III.

This article advocates employing John Stuart Mill's harm principle to set the boundary for unregulated free speech, and his Greatest Happiness Principle to regulate speech outside that boundary because it threatens unconsented-to harm. Supplementing the harm principle with an offense principle is unnecessary and undesirable if our conception of harm integrates recent empirical evidence unavailable to Mill. For example, current research uncovers the tangible harms individuals suffer directly from bigoted speech, as well as the indirect harms generated by the systemic oppression and epistemic injustice that bigoted speech constructs and reinforces. Using Mill's ethical framework with an updated notion of harm, we can conclude that social coercion is not justified to restrict any harmless speech, no matter how offensive. Yet certain forms of speech, such as bigoted insults, are both harmful and fail to express a genuine opinion, and so do not deserve free speech protection.

This article aims to reconstruct a Millian argument for protecting a broad artistic freedom, as well as to delineate the exceptional cases in which censorship of works of art might be justified. Mill's On Liberty offers two lines of reasoning that might be used to defend the widest possible artistic freedom. The first is Mill's defense of freedom of speech in chapter 2, although this would apparently still allow for censoring art that serves to instigate harm. The second is his defense of “experiments in living” in chapter 3, but this might allow for censoring the exhibition or publication of artworks that constitute “offences against decency.” While this Millian doctrine on artistic freedom provides guidelines for coping with difficult cases in arts management, its limitations highlight the peculiarities of the arts and literature in relation to freedom and censorship.