To sum up: free speech on campus is threatened from a dozen directions. It is threatened by police spies, overzealous administrators, and students who are intolerant of dissent. It is threatened by activists agitating for speech codes and sanctions for professors or classmates who disagree with them. It is threatened by people who push to disinvite speakers because of their viewpoints and those who shut down events to prevent people from speaking. Harper and Stanley were unpersuaded that free speech is under threat not because they defend speech codes or sanctions––both say outright at different times that they are for untrammeled speech––but because they are blind to the number and degree of threats to speech.

And this whole discussion has been restricted to documented, overt threats to speech. Chilling effects are harder to quantify or cite, but they are real. Professors and students see those around them being punished for their viewpoints and decide to hold their tongues rather than speak their minds. Stanley denies that this is a significant problem. And yet, last semester, without looking very hard, I found and spoke to tenured and non-tenured professors and students at Yale, his own institution, who told me that their speech was chilled. They feared that their place at the school would be jeopardized if they opined honestly about campus controversies; or did not want to be targets of intolerant activists like the ones who spat on lecture attendees because the activists disagreed with words spoken at the lecture.