This essay introduces basic issues that make up the topic of freedom of thought, including newly emerging issues raised by the current proliferation of Internet search algorithms.

Mill advocated an unqualified defense of the liberty of conscience in the most comprehensive sense, which he understood to include not just the freedom to hold but also to express any opinion or sentiment. Yet considerable dispute persists about the nature of Mill’s argument for freedom of expression and whether his premises can support so strong a conclusion. Two prominent interpretations of Mill that threaten to undermine his uncompromising defense of free speech are considered and refuted. A better interpretation can be founded on Mill’s claim that the liberties of conscience are inseparable in practice. This claim can be defended with modern psychological insight about the nature of cognitive bias, and epistemological insight about why justification of creedal beliefs requires the universal toleration of opinion, insights which are largely anticipated by Mill. This argument is especially vital because it highlights the divide between classical liberalism and progressivism that has become a flashpoint in the current political debate over free speech.

While autonomy arguments provide a compelling foundation for free speech, they also support individual privacy rights. Considering how speech and privacy may be justified, I will argue that the speech necessary for self-government does not need to include details that would violate privacy rights. Additionally, I will argue that if viewed as a kind of intangible property right, informational privacy should limit speech and expression in a range of cases. In a world where we have an overabundance of content to consume, much of which could be called “information pollution,” and where there are numerous platforms to broadcast one’s expressions, it is increasingly difficult to maintain that speech should trump privacy.

Freedom of thought means freedom from social tyranny, the capacity to think for oneself, to encounter even shocking ideas without shrinking away from them. That aspiration is a core concern of the free speech tradition. It is not specifically concerned with law, but it explains some familiar aspects of the First Amendment law we actually have—aspects that the most prevalent theories of free speech fail to capture. It explains the prohibition of compelled speech, and can clarify the perennial puzzle of why freedom of speech extends to art and literature. It also tells us something about the limits of legal regulation, and about the ethical obligations of private actors.

Freedom of thought is often explicitly protected in constitutions and human rights documents, and even more often employed as a rallying cry against state tyranny. It is not so clear, however, just what freedom of thought is, what it would be to threaten it, and how, if at all, it differs from basic liberty or freedom. This essay seeks to analyze the idea of freedom of thought, to pose some skeptical questions about its alleged independent existence, and to ask, again with a skeptical mindset, what it is to protect it and why its protection should be so commonly valued.

Conservatives in the United States have grown increasingly critical of universities and their faculty, convinced that professors are ideologues from the political left. Universities, for their part, have increasingly adopted a mantra of diversity and inclusivity, but have shown little interest in diversifying the political and ideological profile of their faculties. This essay argues that the lack of political diversity among American university faculty hampers the ability of universities to fulfill their core mission of advancing and disseminating knowledge. The argument is advanced through a series of four questions: Is it true that university faculty are not ideologically diverse? Why might it be true? Does it matter? How might it be fixed.

Early in the history of liberalism, its most important proponents were concerned with freedom of religion. As polities and individuals now accept a dizzying array of religions, this has receded to the background for most theorists. It nonetheless remains a concern. Freedom of speech is a similar concern and very much in the foreground for theorists looking at the current state of academia. In this essay, I argue that inappropriate limits to freedom of religion and inappropriate limits to freedom of speech—especially in the form of de-platforming on college campuses—both have, as one of their effects, what I call harms of silence. This means we ought not have those limits, so should seek to change them where they exist.

Suffering can make sacred, so it may partly be nature, and not culture alone, that leads us to apprehend a sacred aspect in victims of oppression. Those who recognize this sacredness show piety—a special form of respect—toward members of oppressed groups. The result is a system of social constructions often dismissed as “identity politics.” This essay starts with an analysis of the intentionality of piety and sacredness and how they relate to suffering, sacrifice, sanctions, pollution, and purification. It then argues that the sacralization of oppressed groups is an expression of the perennial human disposition to acknowledge sacredness and to respond piously. The essay then analyzes this sacred status as socially constructed. Based on the sacred-making (that is, “sacrificial”) power of suffering, the sacred status elicits piety, gives its bearers special authority, surrounds them with sanctions, and calls for symbolic sacrificial punishments of the impious. By dissecting sacrificial politics as a system of social constructions, we see that, although the oppressed groups are made sacred, certain people in the oppressor groups—“the Pious”—continue to exercise fundamental power. This essay, by displaying the inner logic of this cultural phenomenon, helps us both to sympathize with and to critique the system and then to pose questions about what good or bad the system might be doing.

The classical liberal doctrine of free expression asserts the priority of speech as an extension of the freedom of thought. Yet its critics argue that freedom of expression, itself, demands the suppression of the so-called “silencing speech” of racists, sexists, and so on, as a threat to the equal expressive rights of others. This essay argues that the claim to free expression must be distinguished from claims to equal speech. The former asserts an equal right to express one’s thoughts without interference; the latter the right to address others, and to receive a hearing and consideration from them, in turn. I explore the theory of equal speech in light of the ancient Athenian practice of isegoria and argue that the equality demanded is not distributive but relational: an equal speaker’s voice should be counted as “on a par” with others. This ideal better captures critics’ concerns about silencing speech than do their appeals to free expression. Insofar as epistemic and status-harms provide grounds for the suppression and exclusion of some speech and speakers, the ideal of equal speech is more closely connected with the freedom of association than of thought. Noticing this draws attention to the continuing—and potentially problematic—importance of exclusion in constituting effective sites of equal speech today.

Moral grandstanding, or the use of moral talk for self-promotion, is a threat to free expression. When grandstanding is introduced in a public forum, several ideals of free expression are less likely to be realized. Popular views are less likely to be challenged, people are less free to entertain heterodox ideas, and the cost of changing one’s mind goes up.

According to Tocqueville, the freedom of the press, which he treats as an extension of the freedom of speech, is a primary constituent element of liberty. Tocqueville treats the freedom of the press in relation to and as an extension of the right to assemble and govern one’s own affairs, both of which he argues are essential to preserving liberty in a free society. Although scholars acknowledge the importance of civil associations to liberty in Tocqueville’s political thought, they routinely ignore the importance he places on the freedom of the press and speech. His reflections on the importance of the free press and speech may help to shed light on the dangers of recent attempts to censor the press and speech.

I have argued elsewhere that in past history, freedom of speech, whether granted to few or many, was granted as bestowing some important benefit. John Stuart Mill, for example, in On Liberty, saw it as enabling us to learn from each other through discussion. By the test of benefit, I here argue that social media that are funded through trade in our personal data with advertisers, including propagandists, cannot claim to be supporting free speech. We lose our freedoms, if the personal data we entrust to online social media are used to target us with information, or disinformation, tailored as persuasive to different personalities, in order to maximize revenue from advertisers or propagandists. Among the serious consequences described, particularly dangerous because of its effect on democracy, is the use of such targeted advertisements to swing voting campaigns. Control is needed both of the social media and of any political parties that pay social media for differential targeting of voters based on personality. Using UK government documents, I recommend legislation for reform and enforcement.

In this essay, I explore ethical considerations that might arise from the use of collaborative filtering algorithms on dating apps. Collaborative filtering algorithms can predict the preferences of a target user by looking at the past behavior of similar users. By recommending products through this process, they can influence the news we read, the movies we watch, and more. They are extremely powerful and effective on platforms like Amazon and Google. Recommender systems on dating apps are likely to group people by race, since they exhibit similar patterns of behavior: users on dating platforms seem to segregate themselves based on race, exclude certain races from romantic and sexual consideration (except their own), and generally show a preference for white men and women. As collaborative filtering algorithms learn from these patterns to predict preferences and build recommendations, they can homogenize the behavior of dating app users and exacerbate biased sexual and romantic behavior.

A person’s epistemic goals sometimes clash with pragmatic ones. At times, rational agents will degrade the quality of their epistemic process in order to satisfy a goal that is knowledge-independent (for example, to gain status or at least keep the peace with friends.) This is particularly so when the epistemic quest concerns an abstract political or economic theory, where evidence is likely to be softer and open to interpretation. Before wide-scale adoption of the Internet, people sought out or stumbled upon evidence related to a proposition in a more random way. And it was difficult to aggregate the evidence of friends and other similar people to the exclusion of others, even if one had wanted to. Today, by contrast, the searchable Internet allows people to simultaneously pursue social and epistemic goals.

This essay shows that the selection effect caused by a merging of social and epistemic activities will cause both polarization in beliefs and devaluation of expert testimony. This will occur even if agents are rational Bayesians and have moderate credences before talking to their peers. What appears to be rampant dogmatism could be just as well explained by the nonrandom walk in evidence-gathering. This explanation better matches the empirical evidence on how people behave on social media platforms. It also helps clarify why media outlets (not just the Internet platforms) might have their own pragmatic reasons to compromise their epistemic goals in today’s competitive and polarized information market. Yet, it also makes policy intervention much more difficult, since we are unlikely to neatly separate individuals’ epistemic goals from their social ones.