For a reader “just browsing” the book, there is a natural inclination to skip ahead to chapter three and some of the specific sections there. In that chapter, I take up the various kinds of controversies that have recently roiled university campuses in the United States and elsewhere and apply general principles of free speech to help us think through how we should resolve them. That chapter is full of specific examples of controversies that have arisen and things that have gone wrong on college campuses. What are safe spaces, and do they have a place on a college campus? Must universities regulate “hate speech”? Do demonstrators have a right to shout down speakers with whom they disagree? Should professors who express repulsive views on social media face university discipline? The chapter points to cases where university students, faculty and administrators have behaved rather badly, as well as to some cases where they have behaved admirably.As best I can, I try to explain the range of perspectives and competing concerns that give rise to these sorts of controversies. When you start to dig into most issues, you generally find that things are complicated and the answers are not as obvious as they might seem from a distance. There are often good arguments on all sides of the debate, and despite their disagreements people are often acting in good faith and from good motives. Nonetheless, I think it is possible to make progress on these issues and persuade those who come to these debates with an open mind and a willingness to think about the issues seriously.I hope the sections in this chapter can encourage campus activists to think twice before trying to shout down a speaker, a conservative student group to think twice about whether to invite a provocateur or a serious intellectual to campus, a politician to think twice about whether to call for a professor to be fired for a bad tweet, and university presidents to think twice before issuing public denunciations or worse regarding professors who have become a source of public controversy. Both the left and the right need to make space on campus for their ideological antagonists to have their say – and preferably to learn how to engage with those antagonists with a spirit of both skepticism and charity.I do hope, however, that readers who are just browsing those sections of the book on campus controversies find themselves intrigued enough to dig into other sections of the book, such as the mission of the university and the reasons for extending robust protections to the freedom of speech.I hope the book can contribute to a national conversation about the role of universities in society, about intellectual diversity and free inquiry on college campuses, and ultimately for the value of tolerance of disagreement and dissent in a liberal democracy.In the spring of 2015, I was among a group of professors who spearheaded an effort at Princeton University for the faculty to adopt the University of Chicago’s statement on the principles of free expression. The University of Chicago statement was issued in 2012 and provided an admirable and brief articulation of the importance of free and open inquiry in institutions of higher education. I thought Princeton’s faculty should endorse that statement not because Princeton had a particular problem with free speech on campus but because it was important for us to be seen to reaffirm those values at a time when many across the nation were calling them into question.I would like to see university faculty everywhere taking a lead in fostering a discussion on their own campuses of what core values animate those institutions and the degree to which their own institutions are committed to academic freedom and freedom of speech. Those will sometimes be difficult conversations, and not everyone will always be in agreement. But I think we have seen that if professors are not willing to stand up for the importance of freedom of thought on college campuses, then others will take the opportunity to erode that freedom away. If professors decide to sit on the sidelines on this issue, they should not be surprised to find that someone else – whether students, administrators or politicians – will take it upon themselves to take action and might well impose solutions that restrict the freedom that faculty have long enjoyed on college campuses.Those of us on college campuses need to be more self-conscious about the values that are important to the academic enterprise and make more of an effort to affirm and explain those values and to socialize those who are entering college campuses into understanding and sharing those values. We should not be surprised if first-year undergraduates arrive on college campuses with no appreciation of the importance of civil debate and the appropriate limits on forms of protest on those campuses. We should undertake the work of orienting those students to the expectations and responsibilities of being part of a scholarly community and not just of orienting those students on how to avoid injury while partying and how to find the dining hall. We should undertake the work of informing new graduate students and faculty of the importance of academic freedom and their responsibilities as scholars and teachers.There are no doubt policies and rules on college campuses that implicate free speech and that could use some reform and revision, but the bigger challenge is not how to design good policies but how to foster a good culture. Students and professors alike need to feel comfortable working through difficult ideas. Students and professors alike need to be encouraged to ask hard questions, to challenge received wisdom, to step outside the mainstream, to follow the arguments and evidence wherever they may lead, and to think carefully about the old ideas that they take for granted and the new ideas that they encounter.Ultimately, we should hope that ideas are taken seriously outside of academia as well as inside of it. We would be better off if we could live in a society in which we can productively engage with those with whom we disagree, can approach hard problems with an open mind, and can tolerate those who reach different conclusions than we do. At the very least, members of the campus community should be modelling those traits, and universities should be building communities infused with a spirit of intellectual curiosity and openness to a diverse array of perspectives and ideas.