our interests qua listeners, readers and viewers; and our interests qua bystanders involuntarily affected by the speech of others (see Scanlon 1979). Bystanders’ interests become most relevant when we look at the harms produced by speech; but both speaker- and audience-based interests are especially relevant to the explanation of the value of speech, as we will now see.
Free speech and truth
The best known defence of freedom of speech in political thought is contained in John Stuart Mill’s essay On Liberty (Mill 2006). Although this work was first published in 1859, Mill’s argument for free speech remains a touchstone of contemporary debate, as does his stirring defence of liberty more generally. Mill’s general project in On Liberty was to defend the ‘harm principle’, according to which individuals should be free to do as they wish, unless they harm others; only if they do is there ever a case for legal interference with individual liberty. Mill’s argument is directed against social tyranny; his fear was that popular opinion, allied with the state, could be mobilised to limit the freedom of individuals whose lifestyles are judged foolish, ignoble, strange or avant-garde, since all these challenge majority norms. By contrast, Mill urges us to realise our individuality and to develop a character that is strong, independent-minded, authentic, confident in its convictions, free from the tyranny of the majority, and ready to engage in experiments on ways of living. All this is consistent with, indeed requires, vigorous debate with others.
Mill develops a specific argument for free speech in chapter 2 of On Liberty. It is noteworthy that he does not set out his argument by employing the concept of harm, in other words by arguing that speech is harmless to others. His interest is instead in the special value of speech, which goes above that of ordinary liberty. This special value consists in the fact that speech is necessary for discovering the truth; and, in Mill’s view, knowing the truth is a source of happiness and well-being for both individuals and societies. Mill’s argument for free speech is therefore a consequentialist one; according to him, ‘[t]he truth of an opinion is part of its utility’ (Mill 2006, p. 29). This statement is best understood by considering Mill’s defence of liberty and free speech in his other famous work, Utilitarianism, produced a few years later, in 1863 (Mill 1998): there Mill argues that individuals’ actions, as well as the laws and policies of states, should be guided by the principle of maximising people’s happiness or utility.
Although Mill talks a lot about truth in chapter 2 of On Liberty, his argument needs to be understood in an appropriate way. Truth makes sense in the natural sciences, but what about politics, history, economics, morality, ethics, literature, art and religion? Some people think that there are just different subjective views in these areas and that no one position is objectively true (we may call this ‘Truth’ with a capital T). Yet in all these domains there is ceaseless and often heated discussion and argument, as people advance their ideas and comment on the opinions of others. The views that survive this process are those that can be best defended through the use of speech; they are the most cogent, persuasive, convincing or justifiable ones, even if they are not true in the same way in which ‘2 + 2 = 4’ is true. Conversely, views and opinions that do not convince or persuade others will tend to die away; they will have fewer (if any) adherents. The ‘marketplace of ideas’ is a metaphor often used in connection with Mill’s argument for free speech, even if that precise phrase was first used by the US Supreme Court in Abrams v United States (1919), not by Mill. Just as competitively priced goods attract buyers in the economic market, driving out more expensive goods that are less appealing, so cogent and well-founded views will tend to win out over weaker ones in the realm of competing ideas.
But what is really important for Mill is the process of discovery of more well-founded views. As independent-minded individuals employing our reasoning capacities together, we discuss and deliberate about what is most significant, persuasive, justifiable and so on in various fields. This is what serves our happiness as progressive beings – a happiness of a higher kind. In principle one could imagine an omniscient dictatorship, which used censorship and indoctrination to ensure that citizens hold only true or valid opinions and did so even as it curtailed free speech (Ten 1980). But such a ‘dictatorship of truth’ would possess no value for Mill, because in his eyes utility ultimately resides in people’s opportunity to employ their deliberative capacities. Robbed of this opportunity, citizens would not enjoy the practice of gradually arriving at more defensible views (cf. Brink 2008).
Three specific arguments for free speech, all based on the discovery of truth, can be found in the pages of Mill’s long defence in On Liberty. First, he argues, free speech should be protected because otherwise some cogent or well-founded views would be silenced. As no one knows for sure which views those are, people who restrict the speech of others because they wrongly assume their own infallibility risk depriving themselves and others of the knowledge of silenced yet true opinions. This is often referred to as the infallibility argument. Among the many examples with which Mill illustrates it, that of Galileo Galilei (1564–1642) stands out as especially powerful. An early defender of heliocentrism, Galilei was forced by the Catholic Church to recant his views, which were considered heretical. This act of censorship, grounded in the Church’s assumption that it infallibly ‘knew’ that the sun revolves around the earth, delayed people’s appreciation of the scientific truth. More importantly, it deprived them of the utility that results from genuine knowledge of the universe and from the evaluation of that knowledge through their critical powers. Without free speech, the truth may take longer to emerge – if not fail to do so altogether.
Of course, suppressing free speech may on occasion silence opinions that are clearly false and not really worth hearing. These might include what we nowadays call ‘fake news’. Mill maintains, however, that false opinions, too, play an important role in the marketplace of ideas. This is his second argument, known as the dead dogma argument. By challenging true opinions, false ones help those who know the truth to hold their views in a critical fashion rather than as unexamined ideas or prejudices whose grounds have been forgotten. When well-founded opinions are challenged by false ones, we are offered an opportunity to understand our own views better, as we are compelled to respond to misguided criticisms and flawed claims. If someone wrongly told us that ‘all immigrants are criminals’, for example, we could look at the data on crime, consider our views on the causes of crime, and come up with arguments to defeat our interlocutor, thereby employing our deliberative powers. As a result, well-founded views such as that criminals come from all walks of life and that most immigrants are not criminals would become more meaningful and lively in our minds.
Third, Mill argues that the most defensible position on many subjects is frequently not captured by any single view but is instead shared among different ones. Each view is therefore partially correct, and hence it is important to allow as many opinions as possible to circulate in order for the full truth to emerge (Mill 2006, p. 55). Political parties, he argues, are among the clearest real-world manifestations of this process. More generally, the partial truth argument seems to be especially suitable for explaining the importance of free speech when it comes to moral and political issues, where disagreement is generally the norm, as opposed for example to scientific matters, where the truth often is, indeed, all on one side.
While Mill does not emphasise, in On Liberty, the ways in which speech can harm, he does not overlook them either. In a famous passage, he writes:
An opinion that corn-dealers are starvers of the poor, or that private property is robbery, ought to be unmolested when simply circulated through the press, but may justly incur punishment when delivered orally to an excited mob assembled before the house of a corn-dealer, or when handed about among the same mob in the form of a placard. (Mill 2006, p. 64)
This example looks like what we would nowadays call ‘incitement to hatred’, whereby a speaker stirs up hatred or hostility in the audience against a bystander, possibly causing violence. While Mill’s bystanders are relatively privileged corn dealers and property owners, contemporary laws against incitement to hatred are generally intended to protect vulnerable religious, ethnic or other minorities.
Other restrictions consistent with Mill’s doctrine concern forms of