How much disagreement, over which matters, can a society sustain before it reaches the breaking point? Teresa Bejan's erudite and eloquent book shows us that this all-too-timely question has been with us for a long while, and how well it behooves us to return to early modern thinkers for whom the choice between the toleration of disagreement, on the one hand, and bloodshed, on the other, was even more immediate than it is for us. Bejan's turn to three exemplary early modern thinkers—Hobbes and Locke, to whom she fruitfully adds the less-studied Roger Williams—would not be so interesting if she stuck to the standard storyline: the necessity of putting a stop to the violence of the Wars of Religion gave birth to the inventions by which modern constitutionalists have sought to solve the problem of forging a society out of people who disagree about the most fundamental questions.

While we tend to cluster these inventions—state noninterference in the internal affairs of religious communities, rights of free association and freedom of conscience, rights of free speech and expression—the originality of Bejan's study arises, in the first instance, from her disaggregation of these political devices. In this regard, she has recovered an important and fascinating historical fact: some early modern regimes of official toleration went hand in hand with robust rights of free speech, but others placed strong restrictions on speech when it came to voicing opinions about others’ religious beliefs. These “religious insult” laws bear a striking resemblance to the hate-speech restrictions that we are wont to believe are the innovation of a post-Holocaust world. Noticing these variations in the regulation of speech enables us to see that although official toleration is a necessary condition of a civil society that can be shared among people who fundamentally disagree, it is not a sufficient one. Official toleration addresses the relation between the state and individual members of society, but leaves unanswered the question of how they are to relate to one another. To share civil society, citizens must treat each other civilly, but what does that mean in practice?

Our views about civility turn on our views about the limits of toleration, which, as Bejan argues (152), we can break down into a three-part question: “(1) how much difference we can bear, (2) how much must we share in order to make that difference bearable, and (3) where should we draw the line?” Bejan's claim is that theories of civility should be understood as alternative answers to the second question. However, by drawing our focus there, she takes our eyes off the first and most important question. In so doing, she draws our attention away from the problem of violence as the absolute limit of what we can bear. By focusing on speech, Bejan unduly minimizes the centrality of violence in the history of toleration, in the history of ideas about toleration, and in our consideration of the standards of civility appropriate to our own times.

We tolerate more disagreement, the less we have to lose from it. As Bejan acknowledges, there is thus a “prudential calculus” at the heart of judgments about what to tolerate and what not to tolerate. Indeed, one of the most original insights of her reading of Locke is to trace the shifting prudential calculus through which he converted from “intolerant Hobbism” to not only an acceptance of official toleration but also a rejection of the religious insult laws he had earlier supported. What I want to suggest is that the difference between the conceptions of civility offered by Williams, Hobbes, and Locke reflects differences between the prudential calculus each performed in assessing the costs of disagreement not just in general or in the abstract, but in the concrete social contexts in and to which they were writing.

When Hobbes entertained the thought that it would have been better to kill off one thousand seditious Presbyterian preachers than allow the hundred thousand deaths caused by the English Civil War, he was not indulging in hyperbolic hypotheticals in order to defend sovereign control over religious belief. Bejan comments that the Hobbes who could entertain such a thought “is hardly one that will satisfy modern liberals, just as difference without disagreement would not have satisfied radical tolerationists like Williams in his own day” (110). But this is too quick in casting the difference between Hobbes, modern liberals, and Williams as a difference of opinion. Hobbes's estimate of the deaths immediately caused by the English Civil War was quite accurate. Modern liberals (at least in Western democracies) do not confront a social reality in which heated rhetoric is likely to generate deaths on this scale, and if they did it is very likely that their calculus would be similar to Hobbes's. Neither did Williams confront a social context in which large-scale killing was likely to result from intemperate speech. His own intemperate speech led to his banishment, not his execution. As for Locke, his shift from Hobbism to a more robust defense of toleration might track the decline of religious violence after the Glorious Revolution, in which case there would have been less and less to fear from disagreement, but also more to hope for from agreement: the trust that underwrote his project of civil concordia also underwrote contract and commerce.

In characterizing contemporary debates over free speech and civility, Bejan similarly invokes a potentially shifting “prudential calculus.” First Amendment absolutists, she provocatively (and truly insightfully) argues, are heirs to the evangelical free-speech tradition of which Williams was an exemplar. Their opponents argue that the stakes are too high, particularly when it comes to hate speech. But “what if … the prudential calculus shifts?” Bejan asks. “Defenders of free speech can cite studies showing that laws banning religious insult are counterproductive, but their opponents can always cite the latest massacre” (173). Yet there are massacres to cite, and it is not hyperbolic to draw a connection between hate speech and the massacres of nine churchgoers in Charleston in 2015 and of six people (and the injury of nineteen more) at a Quebec City mosque in January of 2017.

Williams's embrace of vigorous disagreement sounds appealing, but it is important to keep reminding ourselves of something that Bejan also acknowledges: that our views about civility reflect our own partial positions. While the repressive potential of restrictions of speech on university campuses, hate-speech regulations, and “trigger warnings” all have the potential to shut down discourse as the most important medium we have to sustain a shared commitment to what Bejan calls “unmurderous coexistence,” it is a mistake to lose contact with vulnerability to violence as our most enduring and important touchstone for the dictates of civility and the limits of toleration. Those who ridicule “liberal snowflakes” for getting angry about racist, misogynist, heterosexist, anti-immigrant, and Islamophobic speech are generally not vulnerable when what begins as an incitement to discourse ends as an incitement to violence. When we carry out our prudential calculus, the bottom line must be assessed from the standpoint of those who have the most to lose from incivility. This brilliant book does not take a definitive stance against this argument, but it would benefit from being less agnostic about it.